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Sexual intercourse (or coitus or copulation) is a
sexual activity
Human sexual activity, human sexual practice or human sexual behaviour is the manner in which humans experience and express their sexuality. People engage in a variety of sexual acts, ranging from activities done alone (e.g., masturbation) ...
typically involving the insertion and
thrusting
Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that sys ...
of the
penis
A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males do n ...
into the
vagina
In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hymen ...
for
sexual pleasure
Sexual stimulation is any stimulus (including bodily contact) that leads to, enhances and maintains sexual arousal, and may lead to orgasm. Although sexual arousal may arise without physical stimulation, achieving orgasm usually requires physica ...
or
reproduction
Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual or ...
.
[Sexual intercourse most commonly means penile–vaginal penetration for sexual pleasure or sexual reproduction; dictionary sources state that it especially means this, and scholarly sources over the years agree. See, for example;
*
*
*
*
*
*
*
*
*] This is also known as vaginal intercourse or vaginal sex.
Other forms of
penetrative sexual intercourse include
anal sex
Anal sex or anal intercourse is generally the insertion and thrusting of the erect penis into a person's anus, or anus and rectum, for sexual pleasure.Sepages 270–271for anal sex information, anpage 118for information about the clitoris. ...
(penetration of the
anus
The anus (Latin, 'ring' or 'circle') is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, the residual semi-solid waste that remains after food digestion, which, d ...
by the penis),
oral sex
Oral sex, sometimes referred to as oral intercourse, is sexual activity involving the stimulation of the genitalia of a person by another person using the mouth (including the lips, tongue, or teeth) and the throat. Cunnilingus is oral sex per ...
(penetration of the mouth by the penis or oral penetration of the female
genitalia
A sex organ (or reproductive organ) is any part of an animal or plant that is involved in sexual reproduction. The reproductive organs together constitute the reproductive system. In animals, the testis in the male, and the ovary in the female, a ...
),
fingering (sexual penetration by the fingers) and penetration by use of a
dildo
A dildo is a sex toy, often explicitly phallic in appearance, intended for sexual penetration or other sexual activity during masturbation or with sex partners. Dildos can be made from a number of materials and shaped like an erect human penis ...
(especially a
strap-on dildo
A strap-on dildo (also strap-on) is a dildo designed to be worn, usually with a harness, during sexual activity. Harnesses and dildos are made in a wide variety of styles, with variations in how the harness fits the wearer, how the dildo attach ...
).
These activities involve
physical intimacy
Physical intimacy is sensual proximity or touching. It is an act or reaction, such as an expression of feelings (including close friendship, platonic love, romantic love or sexual attraction), between people. Examples of physical intimacy i ...
between two or more individuals and are usually used among humans solely for physical or
emotional
Emotions are mental states brought on by neurophysiological changes, variously associated with thoughts, feelings, behavioral responses, and a degree of pleasure or displeasure. There is currently no scientific consensus on a definition. E ...
pleasure and can contribute to
human bonding
Human bonding is the process of development of a close, interpersonal relationship between two or more people. It most commonly takes place between family members or friends, but can also develop among groups, such as sporting teams and whenever ...
.
There are different views on what constitutes sexual intercourse or other sexual activity
Human sexual activity, human sexual practice or human sexual behaviour is the manner in which humans experience and express their sexuality. People engage in a variety of sexual acts, ranging from activities done alone (e.g., masturbation) ...
, which can impact on views on sexual health
Sexual and reproductive health (SRH) is a field of research, healthcare, and social activism that explores the health of an individual's reproductive system and sexual wellbeing during all stages of their life.
The term can also be further de ...
. Although ''sexual intercourse'', particularly the term ''coitus,'' generally denotes penile–vaginal penetration and the possibility of creating offspring
In biology, offspring are the young creation of living organisms, produced either by a single organism or, in the case of sexual reproduction, two organisms. Collective offspring may be known as a brood or progeny in a more general way. This ca ...
, it also commonly denotes penetrative oral sex and penile–anal sex, especially the latter.[
*
*] It usually encompasses sexual penetration, while non-penetrative sex
Non-penetrative sex or outercourse is sexual activity that usually does not include sexual penetration. It generally excludes the penetrative aspects of vaginal, anal, or oral sexual activity, but includes various forms of sexual and non-sexua ...
has been labeled "outercourse",[
*
*] but non-penetrative sex may also be considered sexual intercourse. ''Sex'', often a shorthand for ''sexual intercourse'', can mean any form of sexual activity. Because people can be at risk of contracting sexually transmitted infections
Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases (STDs) and the older term venereal diseases, are infections that are spread by sexual activity, especially vaginal intercourse, anal sex, and oral se ...
during these activities, safer sex
In cryptography, SAFER (Secure And Fast Encryption Routine) is the name of a family of block ciphers designed primarily by James Massey (one of the designers of IDEA) on behalf of Cylink Corporation. The early SAFER K and SAFER SK designs share t ...
practices are recommended by health professionals to reduce transmission risk.
Various jurisdictions place restrictions on certain sexual acts, such as incest
Incest ( ) is human sexual activity between family members or close relatives. This typically includes sexual activity between people in consanguinity (blood relations), and sometimes those related by affinity (marriage or stepfamily), adoption ...
, sexual activity with minors, prostitution
Prostitution is the business or practice of engaging in Sex work, sexual activity in exchange for payment. The definition of "sexual activity" varies, and is often defined as an activity requiring physical contact (e.g., sexual intercourse, n ...
, rape
Rape is a type of sexual assault usually involving sexual intercourse or other forms of sexual penetration carried out against a person without their consent. The act may be carried out by physical force, coercion, abuse of authority, or ag ...
, zoophilia
Zoophilia is a paraphilia involving a sexual fixation on non-human animals. Bestiality is cross-species sexual activity between humans and non-human animals. The terms are often used interchangeably, but some researchers make a distinction b ...
, sodomy
Sodomy () or buggery (British English) is generally anal or oral sex between people, or sexual activity between a person and a non-human animal ( bestiality), but it may also mean any non- procreative sexual activity. Originally, the term ''sodo ...
, premarital and extramarital sex
Extramarital sex occurs when a married person engages in sexual activity with someone other than their spouse.
The term may be applied to the situation of a single person having sex with a married person.
Where extramarital sexual relations do n ...
. Religious
Religion is usually defined as a social system, social-cultural system of designated religious behaviour, behaviors and practices, morality, morals, beliefs, worldviews, religious text, texts, sacred site, sanctified places, prophecy, prophecie ...
beliefs also play a role in personal decisions about sexual intercourse or other sexual activity, such as decisions about virginity
Virginity is the state of a person who has never engaged in sexual intercourse. The term ''virgin'' originally only referred to sexually inexperienced women, but has evolved to encompass a range of definitions, as found in traditional, modern ...
, or legal and public policy matters. Religious views on sexuality vary significantly between different religions and sects of the same religion, though there are common themes, such as prohibition of adultery
Adultery (from Latin ''adulterium'') is extramarital sex that is considered objectionable on social, religious, moral, or legal grounds. Although the sexual activities that constitute adultery vary, as well as the social, religious, and legal ...
.
Reproductive sexual intercourse between non-human animals is more often called ''copulation
Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetrat ...
'', and sperm
Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, whi ...
may be introduced into the female's reproductive tract in non-vaginal ways among the animals, such as by cloaca
In animal anatomy, a cloaca ( ), plural cloacae ( or ), is the posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles and birds, a ...
l copulation. For most non-human mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
s, mating
In biology, mating is the pairing of either opposite-sex or hermaphroditic organisms for the purposes of sexual reproduction. ''Fertilization'' is the fusion of two gametes. ''Copulation'' is the union of the sex organs of two sexually reproduc ...
and copulation occur at the point of estrus
The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous p ...
(the most fertile period of time in the female's reproductive cycle), which increases the chances of successful impregnation. However, bonobo
The bonobo (; ''Pan paniscus''), also historically called the pygmy chimpanzee and less often the dwarf chimpanzee or gracile chimpanzee, is an endangered great ape and one of the two species making up the genus '' Pan,'' the other being the comm ...
s, dolphin
A dolphin is an aquatic mammal within the infraorder Cetacea. Dolphin species belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontoporiidae (the ...
s and chimpanzee
The chimpanzee (''Pan troglodytes''), also known as simply the chimp, is a species of great ape native to the forest and savannah of tropical Africa. It has four confirmed subspecies and a fifth proposed subspecies. When its close relative th ...
s are known to engage in sexual intercourse regardless of whether the female is in estrus, and to engage in sex acts with same-sex partners.[
*
*] Like humans engaging in sexual activity primarily for pleasure, this behavior in these animals is also presumed to be for pleasure, and a contributing factor to strengthening their social bonds.
Behaviors
Definitions
''Sexual intercourse'' may be called ''coitus'', ''copulation'', ''coition'', or ''intercourse''. ''Coitus'' is derived from the Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
word ''coitio'' or ''coire'', meaning "a coming together or joining together" or "to go together", and is known under different ancient Latin names for a variety of sexual activities, but usually denotes penile–vaginal penetration.[
*
*
*
] This is often called ''vaginal intercourse'' or ''vaginal sex.''[Se]
page 302
for orgasm information, an
pages 285–286
for definitions, prevalence and length of sexual intercourse. ''Vaginal sex,'' and less often ''vaginal intercourse'', may also denote any vaginal sexual activity, particularly if penetrative, including sexual activity between lesbian couples. ''Copulation'', by contrast, more often denotes the mating
In biology, mating is the pairing of either opposite-sex or hermaphroditic organisms for the purposes of sexual reproduction. ''Fertilization'' is the fusion of two gametes. ''Copulation'' is the union of the sex organs of two sexually reproduc ...
process, especially for non-human animals; it can mean a variety of sexual activities between opposite-sex or same-sex pairings, but generally means the sexually reproductive act of transferring sperm
Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, whi ...
from a male to a female or sexual procreation between a man and a woman.
Although ''sex'' and "having sex" also most commonly denote penile–vaginal intercourse,[
*
*
*Se]
page 11 onwards
an
pages 47–49
for views on what constitutes virginity loss and therefore sexual intercourse or other sexual activity; source discusses how gay and lesbian individuals define virginity loss, and how the majority of researchers and heterosexuals define virginity loss/"technical virginity" by whether a person has engaged in penile–vaginal sex.
*
*
* ''sex'' can be significantly broad in its meaning and may cover any penetrative or non-penetrative sexual activity between two or more people. The World Health Organization
The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of h ...
(WHO) states that non-English languages and cultures use different words for sexual activity, "with slightly different meanings". Various vulgarisms
In the study of language and literary style, a vulgarism is an expression or usage considered non-standard or characteristic of uneducated speech or writing. In colloquial or lexical English, "vulgarism" or "vulgarity" may be synonymous with profan ...
, slang
Slang is vocabulary (words, phrases, and linguistic usages) of an informal register, common in spoken conversation but avoided in formal writing. It also sometimes refers to the language generally exclusive to the members of particular in-gro ...
, and euphemism
A euphemism () is an innocuous word or expression used in place of one that is deemed offensive or suggests something unpleasant. Some euphemisms are intended to amuse, while others use bland, inoffensive terms for concepts that the user wishes ...
s are used for sexual intercourse or other sexual activity, such as ''fuck
''Fuck'' is an English-language expletive. It often refers to the act of sexual intercourse, but is also commonly used as an intensifier or to convey disdain. While its origin is obscure, it is usually considered to be first attested to aro ...
'', ''shag'', and the phrase "sleep together". The laws of some countries use the euphemism "carnal knowledge
Carnal knowledge is an archaic or legal euphemism for sexual intercourse. In modern statutes, the term "sexual penetration" is widely used, though with various definitions.
Biblical source
The term derives from ''carnal'', meaning "of the flesh ...
". Penetration of the vagina by the erect penis is additionally known as ''intromission'', or by the Latin name '' immissio penis
A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males do n ...
'' (Latin for "insertion of the penis"). The age of first sexual intercourse is called ''sexarche''.
Vaginal, anal and oral sex are recognized as sexual intercourse more often than other sexual behaviors.[
*
*
*] Sexual activity that does not involve penile-vaginal sex or other sexual penetration might be used to retain virginity (sometimes called "technical virginity
Virginity is the state of a person who has never engaged in sexual intercourse. The term ''virgin'' originally only referred to sexually inexperienced women, but has evolved to encompass a range of definitions, as found in traditional, modern ...
)" or labeled "outercourse".[
*Se]
page 11 onwards
an
pages 47–49
for views on what constitutes virginity loss and therefore sexual intercourse or other sexual activity; source discusses how gay and lesbian individuals define virginity loss, and how the majority of researchers and heterosexuals define virginity loss/"technical virginity" by whether a person has engaged in penile–vaginal sex.
*
*
* One reason virginity loss is often based on penile–vaginal intercourse is because heterosexual couples may engage in anal or oral sex as a way of being sexually active while maintaining that they are virgins since they have not engaged in the reproductive act of coitus.[
*Se]
page 11 onwards
an
pages 47–49
for views on what constitutes virginity loss and therefore sexual intercourse or other sexual activity; source discusses how gay and lesbian individuals define virginity loss, and how the majority of researchers and heterosexuals define virginity loss/"technical virginity" by whether a person has engaged in penile–vaginal sex.
*
* Some gay men
Gay men are male homosexuals. Some bisexual and homoromantic men may also dually identify as gay, and a number of young gay men also identify as queer. Historically, gay men have been referred to by a number of different terms, including ' ...
consider frot
Frot or frotting (slang for frottage; ) is a non-penetrative form of male-to-male sexual activity that usually involves direct penis-to-penis contact. The term was popularized by gay men activists who disparaged the practice of anal sex, but ...
ting or oral sex as a way of maintaining their virginities, with penile-anal penetration used as sexual intercourse and for virginity loss, while other gay men may consider frotting or oral sex as their main forms of sexual activity. Lesbians may categorize oral sex or fingering as sexual intercourse and subsequently an act of virginity loss,[Se]
page 11 onwards
an
pages 47–49
for views on what constitutes virginity loss and therefore sexual intercourse or other sexual activity; source discusses how gay and lesbian individuals define virginity loss, and how the majority of researchers and heterosexuals define virginity loss/"technical virginity" by whether a person has engaged in penile–vaginal sex. or tribadism
Tribadism ( ) or tribbing, commonly known by its scissoring position, is a lesbian sexual practice in which a woman rubs her vulva against her partner's body for sexual stimulation, especially for stimulation of the clitoris. This may involve vulv ...
as a primary form of sexual activity.
Researchers commonly use ''sexual intercourse'' to denote penile–vaginal intercourse while using specific words, such as ''anal sex'' or ''oral sex'', for other sexual behaviors.[
*
*
*Se]
page 11 onwards
an
pages 47–49
for views on what constitutes virginity loss and therefore sexual intercourse or other sexual activity; source discusses how gay and lesbian individuals define virginity loss, and how the majority of researchers and heterosexuals define virginity loss/"technical virginity" by whether a person has engaged in penile–vaginal sex.
*
* Scholars Richard M. Lerner
Richard M. Lerner (born February 23, 1946) is professor of Human Development at Tufts University, occupying the Bergstrom Chair in Applied Developmental Science. Also at Tufts, he directs the Institute for Applied Research in Youth Development. and Laurence Steinberg
Laurence Steinberg (born 1952) is an American university professor of psychology, specializing in adolescent psychological development. Career
Steinberg is a professor at Temple University in Philadelphia, where he is a Distinguished University P ...
state that researchers also "rarely disclose" how they conceptualize sex "or even whether they resolved potential discrepancies" in conceptualizations of sex. Lerner and Steinberg attribute researchers' focus on penile–vaginal sex to "the larger culture's preoccupation with this form of sexual activity," and have expressed concern that the "widespread, unquestioned equation of penile–vaginal intercourse with sex reflects a failure to examine systematically 'whether the respondent's understanding of the question bout sexual activity
Bout can mean:
People
*Viktor Bout, suspected arms dealer
* Jan Everts Bout, early settler to New Netherland
* Marcel Bout
Musical instruments
* The outward-facing round parts of the body shape of violins, guitars, and other stringed instrum ...
matches what the researcher had in mind'". This focus can also relegate other forms of mutual sexual activity to foreplay
Foreplay is a set of emotionally and physically intimate acts between one or more people meant to create sexual arousal and desire for sexual activity. Although foreplay is typically understood as physical sexual activity, nonphysical activitie ...
or contribute to them not being regarded as "real sex", and limits the meaning of rape
Rape is a type of sexual assault usually involving sexual intercourse or other forms of sexual penetration carried out against a person without their consent. The act may be carried out by physical force, coercion, abuse of authority, or ag ...
. It may also be that conceptually conflating sexual activity with vaginal intercourse and sexual function hinders and limits information about sexual behavior that non-heterosexual
Non-heterosexual is a word for a sexual orientation or sexual identity that is not heterosexual. The term helps define the "concept of what is the norm and how a particular group is different from that norm". ''Non-heterosexual'' is used in femi ...
people may be engaging in, or information about heterosexuals who may be engaging in non–vaginal sexual activity.
Studies regarding the meaning of sexual intercourse sometimes conflict. While most consider penile–vaginal intercourse to be sex, whether anal or oral intercourse are considered sex is more debatable, with oral sex ranking lowest. The Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention (CDC) is the national public health agency of the United States. It is a United States federal agency, under the Department of Health and Human Services, and is headquartered in Atlanta, Georgi ...
(CDC) stated that "although there are only limited national data about how often adolescents engage in oral sex, some data suggest that many adolescents who engage in oral sex do not consider it to be 'sex'; therefore they may use oral sex as an option to experience sex while still, in their minds, remaining abstinent". Upton et al. stated, "It is possible that individuals who engage in oral sex, but do not consider it as 'sex', may not associate the acts with the potential health risks they can bring." In other cases, condom
A condom is a sheath-shaped barrier device used during sexual intercourse to reduce the probability of pregnancy or a sexually transmitted infection (STI). There are both male and female condoms. With proper use—and use at every act of in ...
use is a factor, with some men stating that sexual activity involving the protection of a condom is not "real sex" or "the real thing". This view is common among men in Africa, where sexual activity involving the protection of a condom is often associated with emasculation
Emasculation is the removal of both the penis and the testicles, the external male sex organs. It differs from castration, which is the removal of the testicles only, although the terms are sometimes used interchangeably. The potential medical ...
because condoms prevent direct penile–to–skin genital contact.
Stimulation
Sexual intercourse or other sexual activity can encompass various sexually stimulating
Sexual stimulation is any stimulus (including bodily contact) that leads to, enhances and maintains sexual arousal, and may lead to orgasm. Although sexual arousal may arise without physical stimulation, achieving orgasm usually requires physical ...
factors ( physiological stimulation or psychological stimulation), including different sex position
A sex position is a position of the body that people use for sexual intercourse or other sexual activities. Sexual acts are generally described by the positions the participants adopt in order to perform those acts. Though sexual intercourse ge ...
s (such as the missionary position
The missionary position or man-on-top position is a sex position in which, generally, a woman lies on her back and a man lies on top of her while they face each other and engage in vaginal intercourse. The position may also be used for other se ...
, the most common human sex position[Monge-Nájera, J., Rodríguez, M., & González, M. I. (2017). Time to deconstruct the concepts of "foreplay" and "intercourse": the real structure of human sexual encounters. Cuadernos de Investigación UNED, 9(1), 59-64.]) or the use of sex toy
A sex toy is an object or device that is primarily used to facilitate human sexual pleasure, such as a dildo, artificial vagina or vibrator. Many popular sex toys are designed to resemble human genitals, and may be vibrating or non-vibrating ...
s. Foreplay
Foreplay is a set of emotionally and physically intimate acts between one or more people meant to create sexual arousal and desire for sexual activity. Although foreplay is typically understood as physical sexual activity, nonphysical activitie ...
may precede some sexual activities, often leading to sexual arousal
Sexual arousal (also known as sexual excitement) describes the physiological and psychological responses in preparation for sexual intercourse or when exposed to sexual stimuli. A number of physiological responses occur in the body and mind as ...
of the partners and resulting in the erection of the penis
A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males do n ...
or natural lubrication of the vagina
In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hymen ...
. It is also common for people to be as sexually satisfied by being kissed, touched erotically, or held as they are during sexual intercourse.
Non-primate
Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians (monkeys and apes, the latter including huma ...
females copulate only when in estrus
The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous p ...
, but sexual intercourse is possible at any time of the menstrual cycle
The menstrual cycle is a series of natural changes in hormone production and the structures of the uterus and ovaries of the female reproductive system that make pregnancy possible. The ovarian cycle controls the production and release of eggs a ...
for women.[Dixson A.F. (2012]
''Primate sexuality: Comparative studies of the Prosimians, Monkeys, Apes, and Human Beings.''
Oxford University Press, 2nd edition. Sex pheromones
Sex pheromones are pheromones released by an organism to attract an individual of the same species, encourage them to mate with them, or perform some other function closely related with sexual reproduction.
Sex pheromones specifically focus on ind ...
facilitate copulatory reflexes in various organisms, but, in humans, the detection of pheromones is impaired and they have only residual effects.[Doty R.L. (2014]
in Mucignat-Caretta C. (Ed). ''Neurobiology of Chemical Communication.'' Boca Raton (FL): CRC Press, (19). Non-primate females put themselves in the crucial lordosis position
Lordosis behavior (), also known as mammalian lordosis (Greek lordōsis, from ''lordos'' "bent backward") or presenting, is the naturally occurring body posture for sexual receptivity to copulation present in females of most mammals including ro ...
and remain motionless, but these motor copulatory reflexes are no longer functional in women.[Pfaus J.G., Flanagan-Cato L.M., Blaustein J.D. (2015) Female sexual behavior. in Plant T., Zeleznik A. (Eds). Knobil and Neill's Physiology of Reproduction. Academic Press, 4th edition]
During coitus, the partners orient their hips to allow the penis to move back and forth in the vagina to cause friction, typically without fully removing the penis. In this way, they stimulate themselves and each other, often continuing until orgasm in either or both partners is achieved.
For human females, stimulation of the clitoris
The clitoris ( or ) is a female sex organ present in mammals, ostriches and a limited number of other animals. In humans, the visible portion – the glans – is at the front junction of the labia minora (inner lips), above the ope ...
plays a significant role in sexual activity; 70–80% of women require direct clitoral stimulation to achieve orgasm, though indirect clitoral stimulation (for example, via vaginal intercourse) may also be sufficient (see orgasm in females).
Because of this, some couples may engage in the woman on top position or the coital alignment technique
The coital alignment technique (CAT) List of sex positions, sex position, known colloquially as grinding the corn, is used primarily as a variant of the missionary position and is designed to maximize clitoral stimulation during sexual intercourse. ...
, a technique combining the "riding high" variation of the missionary position with pressure-counterpressure movements performed by each partner in rhythm with sexual penetration, to maximize clitoral stimulation.
Anal sex involves stimulation of the anus
The anus (Latin, 'ring' or 'circle') is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, the residual semi-solid waste that remains after food digestion, which, d ...
, anal cavity, sphincter valve or rectum
The rectum is the final straight portion of the large intestine in humans and some other mammals, and the Gastrointestinal tract, gut in others. The adult human rectum is about long, and begins at the rectosigmoid junction (the end of the s ...
; it most commonly means the insertion of a man's penis into another person's rectum, but may also mean the use of sex toys or fingers to penetrate the anus, or oral sex on the anus (anilingus
Anilingus (from the Latin ''anus'' + ''-lingus'', from ''lingere'', "to lick", variantly spelled "analingus") is the oral and anal sex act in which a person stimulates the anus of another by using the mouth, including lips, tongue, or teeth. I ...
), or pegging.
Oral sex consists of all the sexual activities that involve the use of the mouth and throat to stimulate genitalia
A sex organ (or reproductive organ) is any part of an animal or plant that is involved in sexual reproduction. The reproductive organs together constitute the reproductive system. In animals, the testis in the male, and the ovary in the female, a ...
or anus. It is sometimes performed to the exclusion of all other forms of sexual activity, and may include the ingestion or absorption of semen (during fellatio
Fellatio (also known as fellation, and in slang as blowjob, BJ, giving head, or sucking off) is an oral sex act involving a person stimulating the penis of another person by using the mouth, throat, or both. Oral stimulation of the scrotum may ...
) or vaginal fluids (during cunnilingus
Cunnilingus is an oral sex act performed by a person on the vulva or vagina of another person. The clitoris is the most sexually sensitive part of the human female genitalia, and its stimulation may result in a woman becoming sexually aroused ...
).
Fingering (or digital penetration or digital intercourse) involves the manual manipulation of the clitoris, rest of the vulva
The vulva (plural: vulvas or vulvae; derived from Latin for wrapper or covering) consists of the external sex organ, female sex organs. The vulva includes the mons pubis (or mons veneris), labia majora, labia minora, clitoris, bulb of vestibu ...
, vagina or anus for the purpose of sexual arousal and sexual stimulation; it may constitute the entire sexual encounter or it may be part of mutual masturbation, foreplay or other sexual activities.[
]
Reproduction
Natural human reproduction involves penile–vaginal penetration, during which semen
Semen, also known as seminal fluid, is an organic bodily fluid created to contain spermatozoa. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphroditic animals and can fertilize the female ovum. Semen i ...
, containing male gametes known as sperm
Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, whi ...
cells or spermatozoa, is expelled via ejaculation
Ejaculation is the discharge of semen (the ''ejaculate''; normally containing sperm) from the male reproductory tract as a result of an orgasm. It is the final stage and natural objective of male sexual stimulation, and an essential componen ...
through the penis into the vagina. The sperm passes through the vaginal vault
The vaginal vault is the expanded region of the vaginal canal at the internal end of the vagina.
Prolapse
The vaginal vault may prolapse after a hysterectomy, as there is no uterus supporting the interior end of the vagina.
''Colposacropexy'' is ...
, cervix
The cervix or cervix uteri (Latin, 'neck of the uterus') is the lower part of the uterus (womb) in the human female reproductive system. The cervix is usually 2 to 3 cm long (~1 inch) and roughly cylindrical in shape, which changes during ...
and into the uterus
The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The uter ...
, and then into the fallopian tube
The fallopian tubes, also known as uterine tubes, oviducts or salpinges (singular salpinx), are paired tubes in the human female that stretch from the uterus to the ovaries. The fallopian tubes are part of the female reproductive system. In ot ...
s. Millions of sperm are present in each ejaculation to increase the chances of fertilization
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Proce ...
(see sperm competition
Sperm competition is the competitive process between spermatozoa of two or more different males to fertilize the same egg during sexual reproduction. Competition can occur when females have multiple potential mating partners. Greater choice and ...
), but only one reaching an egg or ovum
The egg cell, or ovum (plural ova), is the female reproductive cell, or gamete, in most anisogamous organisms (organisms that reproduce sexually with a larger, female gamete and a smaller, male one). The term is used when the female gamete is ...
is sufficient to achieve fertilization. When a fertile ovum from the female is present in the fallopian tubes, the male gamete joins with the ovum, resulting in fertilization and the formation of a new embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...
. When a fertilized ovum reaches the uterus, it becomes implanted in the lining of the uterus (the endometrium
The endometrium is the inner epithelial layer, along with its mucous membrane, of the mammalian uterus. It has a basal layer and a functional layer: the basal layer contains stem cells which regenerate the functional layer. The functional laye ...
) and a pregnancy
Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins.
Pregnancy usually occurs by sexual intercourse, but ca ...
begins.
Pregnancy rates for sexual intercourse are highest during the menstrual cycle
The menstrual cycle is a series of natural changes in hormone production and the structures of the uterus and ovaries of the female reproductive system that make pregnancy possible. The ovarian cycle controls the production and release of eggs a ...
time from some 5 days before until 1 to 2 days after ovulation. For optimal pregnancy chance, there are recommendations of sexual intercourse every 1 or 2 days, or every 2 or 3 days. Studies have shown no significant difference between different sex positions
A sex position is a position of the body that people use for sexual intercourse or other sexual activities. Sexual acts are generally described by the positions the participants adopt in order to perform those acts. Though sexual intercourse ge ...
and pregnancy rate, as long as it results in ejaculation
Ejaculation is the discharge of semen (the ''ejaculate''; normally containing sperm) from the male reproductory tract as a result of an orgasm. It is the final stage and natural objective of male sexual stimulation, and an essential componen ...
into the vagina
In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hymen ...
.
When a sperm donor
Sperm donation is the provision by a man of his sperm with the intention that it be used in the artificial insemination or other 'fertility treatment' of a woman or women who are not his sexual partners in order that they may become pregnant by hi ...
has sexual intercourse with a woman who is not his partner and for the sole purpose of impregnating the woman, this may be known as natural insemination
Insemination is the introduction of sperm into a female’s reproductive system for the purpose of impregnating, also called fertilizing, the female for sexual reproduction. The sperm is introduced into the uterus of a mammal or the oviduct of an ...
, as opposed to artificial insemination
Artificial insemination is the deliberate introduction of sperm into a female's cervix or uterine cavity for the purpose of achieving a pregnancy through in vivo fertilization by means other than sexual intercourse. It is a fertility treatme ...
. Artificial insemination is a form of assisted reproductive technology
Assisted reproductive technology (ART) includes medical procedures used primarily to address infertility. This subject involves procedures such as in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), cryopreservation of gametes o ...
, which are methods used to achieve pregnancy by artificial or partially artificial means. For artificial insemination, sperm donors
Sperm donation is the provision by a man of his sperm with the intention that it be used in the artificial insemination or other 'fertility treatment' of a woman or women who are not his sexual partners in order that they may become pregnant by h ...
may donate their sperm through a sperm bank
A sperm bank, semen bank, or cryobank is a facility or enterprise which purchases, stores and sells human semen. The semen is produced and sold by men who are known as sperm donors. The sperm is purchased by or for other persons for the purpose o ...
, and the insemination is performed with the express intention of attempting to impregnate the female; to this extent, its purpose is the medical equivalent of sexual intercourse. Reproductive methods also extend to gay and lesbian couples. For gay male pairings, there is the option of surrogate
A surrogate is a substitute or deputy for another person in a specific role and may refer to:
Relationships
* Surrogacy, an arrangement where a woman agrees to carry and give birth to a child for another person who will become its parent at bi ...
pregnancy; for lesbian couples, there is donor insemination in addition to choosing surrogate pregnancy.
Safe sex and birth control
There are a variety of safe sex
Safe sex is sexual activity using methods or contraceptive devices (such as condoms) to reduce the risk of transmitting or acquiring sexually transmitted infections (STIs), especially HIV. "Safe sex" is also sometimes referred to as safer se ...
methods that are practiced by heterosexual and same-sex couples, including non-penetrative sex acts, and heterosexual couples may use oral or anal sex (or both) as a means of birth control. However, pregnancy can still occur with anal sex or other forms of sexual activity if the penis is near the vagina (such as during intercrural sex
Intercrural sex, which is also known as coitus interfemoris, thigh sex (or thighing) and interfemoral sex, is a type of non-penetrative sex in which the penis is placed between the receiving partner's thighs and friction is generated via thrust ...
or other genital-genital rubbing
A sex position is a position of the body that people use for sexual intercourse or other sexual activities. Sexual acts are generally described by the positions the participants adopt in order to perform those acts. Though sexual intercourse ...
) and its sperm is deposited near the vagina's entrance and travels along the vagina's lubricating fluids; the risk of pregnancy can also occur without the penis being near the vagina because sperm may be transported to the vaginal opening by the vagina coming in contact with fingers or other non-genital body parts that have come in contact with semen.
Safe sex is a relevant harm reduction
Harm reduction, or harm minimization, refers to a range of public health policies designed to lessen the negative social and/or physical consequences associated with various human behaviors, both legal and illegal. Harm reduction is used to de ...
philosophy and condom
A condom is a sheath-shaped barrier device used during sexual intercourse to reduce the probability of pregnancy or a sexually transmitted infection (STI). There are both male and female condoms. With proper use—and use at every act of in ...
s are used as a form of safe sex and contraception. Condoms are widely recommended for the prevention of sexually transmitted infections
Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases (STDs) and the older term venereal diseases, are infections that are spread by sexual activity, especially vaginal intercourse, anal sex, and oral se ...
(STIs). According to reports by the National Institutes of Health
The National Institutes of Health, commonly referred to as NIH (with each letter pronounced individually), is the primary agency of the United States government responsible for biomedical and public health research. It was founded in the late ...
(NIH) and World Health Organization
The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of h ...
(WHO), correct and consistent use of latex condoms reduces the risk of HIV/AIDS
Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...
transmission by approximately 85–99% relative to risk when unprotected. Condoms are rarely used for oral sex and there is significantly less research on behaviors with regard to condom use for anal and oral sex. The most effective way to avoid sexually transmitted infections is to abstain
Abstention is a term in election procedure for when a participant in a vote either does not go to vote (on election day) or, in parliamentary procedure, is present during the vote, but does not cast a ballot. Abstention must be contrasted with ...
from sexual intercourse, especially vaginal, anal, and oral sexual intercourse.
Decisions and options concerning birth control can be affected by cultural reasons, such as religion, gender role
A gender role, also known as a sex role, is a social role encompassing a range of behaviors and attitudes that are generally considered acceptable, appropriate, or desirable for a person based on that person's sex. Gender roles are usually cent ...
s or folklore
Folklore is shared by a particular group of people; it encompasses the traditions common to that culture, subculture or group. This includes oral traditions such as tales, legends, proverbs and jokes. They include material culture, ranging ...
. In the predominantly Catholic
The Catholic Church, also known as the Roman Catholic Church, is the largest Christian church, with 1.3 billion baptized Catholics worldwide . It is among the world's oldest and largest international institutions, and has played a ...
countries Ireland, Italy and the Philippines, fertility awareness
Fertility awareness (FA) refers to a set of practices used to determine the fertile and infertile phases of a woman's menstrual cycle. Fertility awareness methods may be used to avoid pregnancy, to achieve pregnancy, or as a way to monitor gynec ...
and the rhythm method
Calendar-based methods are various methods of estimating a woman's likelihood of fertility, based on a record of the length of previous menstrual cycles. Various methods are known as the Knaus–Ogino method and the rhythm method. The standard days ...
are emphasized while disapproval is expressed with regard to other contraceptive methods. Worldwide, sterilization is a more common birth control method, and use of the intrauterine device
An intrauterine device (IUD), also known as intrauterine contraceptive device (IUCD or ICD) or coil, is a small, often T-shaped birth control device that is inserted into the uterus to prevent pregnancy. IUDs are one form of long-acting rever ...
(IUD) is the most common and effective way of reversible contraception. Conception and contraception are additionally a life-and-death situation in developing countries
A developing country is a sovereign state with a lesser developed industrial base and a lower Human Development Index (HDI) relative to other countries. However, this definition is not universally agreed upon. There is also no clear agreem ...
, where one in three women give birth before age 20; however, 90% of unsafe abortion
An unsafe abortion is the termination of a pregnancy by people lacking the necessary skills, or in an environment lacking minimal medical standards, or both. An unsafe abortion is a life-threatening procedure. It includes self-induced abortions, a ...
s in these countries could be prevented by effective contraception use.
The National Survey of Sexual Health and Behavior
The National Survey of Sexual Health and Behavior is a decade-long nationally representative study of human sexual behavior. The research has been conducted in the United States by researchers from the Center for Sexual Health Promotion in the Scho ...
(NSSHB) indicated in 2010 that "1 of 4 acts of vaginal intercourse are condom-protected in the U.S. (1 in 3 among singles)," that "condom use is higher among black and Hispanic Americans than among white Americans and those from other racial groups," and that "adults using a condom for intercourse were just as likely to rate the sexual extent positively in terms of arousal, pleasure and orgasm than when having intercourse without one".
Prevalence
Penile–vaginal penetration is the most common form of sexual intercourse. Studies indicate that most heterosexual couples engage in vaginal intercourse nearly every sexual encounter. The National Survey of Sexual Health and Behavior (NSSHB) reported in 2010 that vaginal intercourse is "the most prevalent sexual behavior among men and women of all ages and ethnicities". Clint E. Bruess et al. stated that it "is the most frequently studied behavior" and is "often the focus of sexuality education programming for youth." Weiten et al. said that it "is the most widely endorsed and practiced sexual act in our society."
Regarding oral or anal intercourse, the CDC stated in 2009, "Studies indicate that oral sex is commonly practiced by sexually active male-female and same-gender couples of various ages, including adolescents." Oral sex is significantly more common than anal sex. The 2010 NSSHB study reported that vaginal intercourse was practiced more than insertive anal intercourse among men, but that 13% to 15% of men aged 25 to 49 practiced insertive anal intercourse. Receptive anal intercourse was infrequent among men, with approximately 7% of men aged 14 to 94 years old having said that they were a receptive partner during anal intercourse. The study said that fewer women reported engaging in anal sex than other partnered sexual behaviors. It was estimated that 10% to 14% of women aged 18 to 39 years old practiced anal sex in the past 90 days, and that most of the women who engage in anal sex said they practiced it once a month or a few times a year.
Age at first intercourse
The prevalence of sexual intercourse has been compared cross-culturally. In 2003, Michael Bozon of the French Institut national d'études démographiques
The French Institute for Demographic Studies (French: ''Institut national d'études démographiques'', INED) is a French research institute specializing in demography and population studies in general.
History Before 1945
In 1941, Nobel Prize wi ...
conducted a cross-cultural study titled "At what age do women and men have their first sexual intercourse?" In the first group of the contemporary cultures he studied, which included sub-Saharan Africa
Sub-Saharan Africa is, geographically, the area and regions of the continent of Africa that lies south of the Sahara. These include West Africa, East Africa, Central Africa, and Southern Africa. Geopolitically, in addition to the List of sov ...
(listing Mali
Mali (; ), officially the Republic of Mali,, , ff, 𞤈𞤫𞤲𞥆𞤣𞤢𞥄𞤲𞤣𞤭 𞤃𞤢𞥄𞤤𞤭, Renndaandi Maali, italics=no, ar, جمهورية مالي, Jumhūriyyāt Mālī is a landlocked country in West Africa. Mali ...
, Senegal
Senegal,; Wolof: ''Senegaal''; Pulaar: 𞤅𞤫𞤲𞤫𞤺𞤢𞥄𞤤𞤭 (Senegaali); Arabic: السنغال ''As-Sinighal'') officially the Republic of Senegal,; Wolof: ''Réewum Senegaal''; Pulaar : 𞤈𞤫𞤲𞤣𞤢𞥄𞤲𞤣𞤭 ...
and Ethiopia
Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...
), the data indicated that the age of men at sexual initiation in these societies is at later ages than that of women, but is often extra-marital; the study considered the Indian subcontinent
The Indian subcontinent is a list of the physiographic regions of the world, physiographical region in United Nations geoscheme for Asia#Southern Asia, Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian O ...
to also fall into this group, though data was only available from Nepal
Nepal (; ne, नेपाल ), formerly the Federal Democratic Republic of Nepal ( ne,
सङ्घीय लोकतान्त्रिक गणतन्त्र नेपाल ), is a landlocked country in South Asia. It is mai ...
.
In the second group, the data indicated families encouraged daughters to delay marriage, and to abstain from sexual activity before that time. However, sons are encouraged to gain experience with older women or prostitutes before marriage. Age of men at sexual initiation in these societies is at lower ages than that of women; this group includes south European and Latin cultures (Portugal, Greece and Romania are noted) and such from Latin America
Latin America or
* french: Amérique Latine, link=no
* ht, Amerik Latin, link=no
* pt, América Latina, link=no, name=a, sometimes referred to as LatAm is a large cultural region in the Americas where Romance languages — languages derived f ...
(Brazil, Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...
, and the Dominican Republic
The Dominican Republic ( ; es, República Dominicana, ) is a country located on the island of Hispaniola in the Greater Antilles archipelago of the Caribbean region. It occupies the eastern five-eighths of the island, which it shares wit ...
). The study considered many Asian societies to also fall into this group, although matching data was only available from Thailand
Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is bo ...
.
In the third group, age of men and women at sexual initiation was more closely matched; there were two sub-groups, however. In non-Latin, Catholic countries (Poland and Lithuania
Lithuania (; lt, Lietuva ), officially the Republic of Lithuania ( lt, Lietuvos Respublika, links=no ), is a country in the Baltic region of Europe. It is one of three Baltic states and lies on the eastern shore of the Baltic Sea. Lithuania ...
are mentioned), age at sexual initiation was higher, suggesting later marriage and reciprocal valuing of male and female virginity. The same pattern of late marriage and reciprocal valuing of virginity was reflected in Singapore
Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, borde ...
and Sri Lanka
Sri Lanka (, ; si, ශ්රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...
. The study considered China and Vietnam to also fall into this group, though data were not available. In northern and eastern European countries, age at sexual initiation was lower, with both men and women involved in sexual intercourse before any union formation; the study listed Switzerland, Germany and the Czech Republic as members of this group.
Concerning United States data, tabulations by the National Center for Health Statistics
The National Center for Health Statistics (NCHS) is a U.S. government agency that provides statistical information to guide actions and policies to improve the public health of the American people. It is a unit of the Centers for Disease Control ...
report that the age of first sexual intercourse was 17.1 years for both males and females in 2010. The CDC stated that 45.5 percent of girls and 45.7 percent of boys had engaged in sexual activity by 19 in 2002; in 2011, reporting their research from 2006 to 2010, they stated that 43% of American unmarried teenage girls and 42% of American unmarried teenage boys have ever engaged in sexual intercourse. The CDC also reports that American girls will most likely lose their virginity to a boy who is 1 to 3 years older than they are. Between 1988 and 2002, the percentage of people in the U.S. who had sexual intercourse between the ages of 15 to 19 fell from 60 to 46 percent for never-married males, and from 51 to 46 percent for never-married females.
Health effects
Vaginal intercourse for the first time increases vaginal immune activity.
Benefits
In humans, sexual intercourse and sexual activity in general have been reported as having health benefits as varied as increased immunity
Immunity may refer to:
Medicine
* Immunity (medical), resistance of an organism to infection or disease
* ''Immunity'' (journal), a scientific journal published by Cell Press
Biology
* Immune system
Engineering
* Radiofrequence immunity desc ...
by increasing the body's production of antibodies
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...
and subsequent lower blood pressure
Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressure" r ...
, and decreased risk of prostate cancer
Prostate cancer is cancer of the prostate. Prostate cancer is the second most common cancerous tumor worldwide and is the fifth leading cause of cancer-related mortality among men. The prostate is a gland in the male reproductive system that sur ...
. Sexual intimacy and orgasms increase levels of the hormone oxytocin
Oxytocin (Oxt or OT) is a peptide hormone and neuropeptide normally produced in the hypothalamus and released by the posterior pituitary. It plays a role in social bonding, reproduction, childbirth, and the period after childbirth. Oxytocin ...
(also known as "the love hormone"), which can help people bond and build trust. Oxytocin is believed to have a more significant impact on women than on men, which may be why women associate sexual attraction or sexual activity with romance and love more than men do. A long-term study of 3,500 people between ages 18 and 102 by clinical neuropsychologist
Neuropsychology is a branch of psychology concerned with how a person's cognition and behavior are related to the brain and the rest of the nervous system. Professionals in this branch of psychology often focus on how injuries or illnesses of t ...
David Weeks indicated that, based on impartial ratings of the subjects' photographs, sex on a regular basis is associated with people looking significantly chronologically younger. However this does not imply causality.
Risks
Sexually transmitted infection
Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases (STDs) and the older term venereal diseases, are infections that are Transmission (medicine), spread by Human sexual activity, sexual activity, especi ...
s (STIs) are bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
, virus
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea.
Since Dmitri Ivanovsky's 1 ...
es or parasites
Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted structurally to this way of lif ...
that are spread
Spread may refer to:
Places
* Spread, West Virginia
Arts, entertainment, and media
* ''Spread'' (film), a 2009 film.
* ''$pread'', a quarterly magazine by and for sex workers
* "Spread", a song by OutKast from their 2003 album ''Speakerboxxx/T ...
by sexual contact, especially vaginal, anal, or oral intercourse, or unprotected sex
Safe sex is sexual activity using methods or contraceptive devices (such as condoms) to reduce the risk of transmitting or acquiring sexually transmitted infections (STIs), especially HIV. "Safe sex" is also sometimes referred to as safer sex ...
. Oral sex is less risky than vaginal or anal intercourse. Many times, STIs initially do not cause symptoms, increasing the risk of unknowingly passing the infection on to a sex partner or others.
There are 19 million new cases of sexually transmitted infections every year in the U.S., and, in 2005, the World Health Organization (WHO) estimated that 448 million people aged 15–49 were infected per year with curable STIs (such as syphilis
Syphilis () is a sexually transmitted infection caused by the bacterium ''Treponema pallidum'' subspecies ''pallidum''. The signs and symptoms of syphilis vary depending in which of the four stages it presents (primary, secondary, latent, an ...
, gonorrhea
Gonorrhea, colloquially known as the clap, is a sexually transmitted infection (STI) caused by the bacterium '' Neisseria gonorrhoeae''. Infection may involve the genitals, mouth, or rectum. Infected men may experience pain or burning with ...
and chlamydia
Chlamydia, or more specifically a chlamydia infection, is a sexually transmitted infection caused by the bacterium ''Chlamydia trachomatis''. Most people who are infected have no symptoms. When symptoms do appear they may occur only several wee ...
). Some STIs can cause a genital ulcer
A genital ulcer is an open sore located on the genital area, which includes the vulva, penis, perianal region, or anus. Genital ulcers are most commonly caused by infectious agents (fungal infections, secondary bacterial infections, or sexually t ...
; even if they do not, they increase the risk of both acquiring and passing on HIV up to ten-fold. Hepatitis B
Hepatitis B is an infectious disease caused by the ''Hepatitis B virus'' (HBV) that affects the liver; it is a type of viral hepatitis. It can cause both acute and chronic infection.
Many people have no symptoms during an initial infection. Fo ...
can also be transmitted through sexual contact. Globally, there are about 257 million chronic carriers of hepatitis B. HIV is one of the world's leading infectious killers; in 2010, approximately 30 million people were estimated to have died because of it since the beginning of the epidemic. Of the 2.7 million new HIV infections estimated to occur worldwide in 2010, 1.9 million (70%) were in Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
. The World Health Organization also stated that the "estimated 1.2 million Africans who died of HIV-related illnesses in 2010 comprised 69% of the global total of 1.8 million deaths attributable to the epidemic." It is diagnosed by blood tests, and while no cure has been found, it can be controlled by management through antiretroviral drugs for the disease, and patients can enjoy healthy and productive lives.
In cases where infection is suspected, early medical intervention is highly beneficial in all cases. The CDC stated "the risk of HIV transmission from an infected partner through oral sex is much less than the risk of HIV transmission from anal or vaginal sex," but that "measuring the exact risk of HIV transmission as a result of oral sex is very difficult" and that this is "because most sexually active individuals practice oral sex in addition to other forms of sex, such as vaginal or anal sex, when transmission occurs, it is difficult to determine whether it occurred as a result of oral sex or other more risky sexual activities". They added that "several co-factors may increase the risk of HIV transmission through oral sex"; this includes ulcers, bleeding gums, genital sores, and the presence of other STIs.
In 2005, the World Health Organization estimated that 123 million women become pregnant worldwide each year, and around 87 million of those pregnancies or 70.7% are unintentional. Approximately 46 million pregnancies per year reportedly end in induced abortion
Abortion is the termination of a pregnancy by removal or expulsion of an embryo or fetus. An abortion that occurs without intervention is known as a miscarriage or "spontaneous abortion"; these occur in approximately 30% to 40% of pregn ...
. Approximately 6 million U.S. women become pregnant per year. Out of known pregnancies, two-thirds result in live births and roughly 25% in abortions; the remainder end in miscarriage. However, many more women become pregnant and miscarry without even realizing it, instead mistaking the miscarriage for an unusually heavy menstruation
Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. The menstrual cycle is characterized by the rise and fall of hor ...
. The U.S. teenage pregnancy
Teenage pregnancy, also known as adolescent pregnancy, is pregnancy in a female adolescent or young adult under the age of 20. This includes those who are legally considered adults in their country. The WHO defines adolescence as the period bet ...
rate fell by 27 percent between 1990 and 2000, from 116.3 pregnancies per 1,000 girls aged 15–19 to 84.5. This data includes live births, abortions, and fetal losses. Almost 1 million American teenage women, 10% of all women aged 15–19 and 19% of those who report having had intercourse, become pregnant each year.
Sexual activity can increase the expression of a gene transcription
Transcription is the process of copying a segment of DNA into RNA. The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). Other segments of DNA are copied into RNA molecules calle ...
factor called ΔFosB
Protein fosB, also known as FosB and G0/G1 switch regulatory protein 3 (G0S3), is a protein that in humans is encoded by the FBJ murine osteosarcoma viral oncogene homolog B (''FOSB'') gene.
The FOS gene family consists of four members: FOS, F ...
(delta FosB) in the brain's reward center; consequently excessively frequent engagement in sexual activity on a regular (daily) basis can lead to the overexpression of ΔFosB, inducing an addiction to sexual activity. Sexual addiction
According to proponents of the concept, sexual addiction, also known as sex addiction, is a state characterized by compulsive participation or engagement in sexual activity, particularly sexual intercourse, despite negative consequences. The con ...
or hypersexuality
Hypersexuality is extremely frequent or suddenly increased libido. It is controversial whether it should be included as a clinical diagnosis used by mental healthcare professionals. Nymphomania and satyriasis were terms previously used for the c ...
is often considered an impulse control disorder or a behavioral addiction. It has been linked to atypical levels of dopamine, a neurotransmitter. This behavior is characterized by a fixation on sexual intercourse and disinhibition. It was proposed that this 'addictive behavior' be classified in DSM-5
The ''Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition'' (DSM-5), is the 2013 update to the ''Diagnostic and Statistical Manual of Mental Disorders'', the taxonomic and diagnostic tool published by the American Psychiatric ...
as an impulsive–compulsive behavioral disorder. Addiction to sexual intercourse is thought to be genetically linked. Those having an addiction to sexual intercourse have a higher response to visual sexual cues in the brain. Those seeking treatment will typically see a physician for pharmacological management and therapy. One form of hypersexuality is Kleine–Levin syndrome
Kleine–Levin syndrome (KLS) is a rare disorder characterized by persistent episodic hypersomnia and cognitive or mood changes. Many patients also experience hyperphagia, hypersexuality and other symptoms. Patients generally experience recurrent e ...
. It is manifested by hypersomnia
Hypersomnia is a neurological disorder of excessive time spent sleeping or excessive sleepiness. It can have many possible causes (such as seasonal affective disorder) and can cause distress and problems with functioning. In the fifth edition ...
and hypersexuality and remains relatively rare.
Sexual activity can directly cause death, particularly due to coronary circulation
Coronary circulation is the circulation of blood in the blood vessels that supply the heart muscle (myocardium).
Coronary arteries supply oxygenated blood to the heart muscle. Cardiac veins then drain away the blood after it has been deoxygenat ...
complications, which is sometimes called ''coital death,'' ''coital sudden death'' or ''coital coronary.'' However, coital deaths are significantly rare. People, especially those who get little or no physical exercise, have a slightly increased risk of triggering a heart attack
A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which may tr ...
or sudden cardiac death
Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and possib ...
when they engage in sexual intercourse or any vigorous physical exercise that is engaged in on a sporadic basis. Regular exercise reduces, but does not eliminate, the increased risk.
Duration and genital complications
Sexual intercourse, when involving a male participant, often ends when the male has ejaculated, and thus the partner might not have time to reach orgasm
Orgasm (from Greek , ; "excitement, swelling") or sexual climax is the sudden discharge of accumulated sexual excitement during the sexual response cycle, resulting in rhythmic, involuntary muscular contractions in the pelvic region charac ...
. In addition, premature ejaculation
Premature ejaculation (PE) occurs when a man expels semen (and most likely experiences orgasm) soon after beginning sexual activity, and with minimal penile stimulation. It has also been called ''early ejaculation'', ''rapid ejaculation'', ''ra ...
(PE) is common, and women often require a substantially longer duration of stimulation with a sexual partner than men do before reaching an orgasm. Scholars, such as Weiten et al., state that "many couples are locked into the idea that orgasms should be achieved only through intercourse enile-vaginal sex" that "the word ''foreplay'' suggests that any other form of sexual stimulation is merely preparation for the 'main event'" and that "because women reach orgasm through intercourse less consistently than men," they are likelier than men to fake an orgasm to satisfy their sexual partners.
In 1991, scholars from the Kinsey Institute stated, "The truth is that the time between penetration and ejaculation varies not only from man to man, but from one time to the next for the same man." They added that the appropriate length for sexual intercourse is the length of time it takes for both partners to be mutually satisfied, emphasizing that Kinsey "found that 75 percent of men ejaculated within two minutes of penetration. But he didn't ask if the men or their partners considered two minutes mutually satisfying" and "more recent research reports slightly longer times for intercourse". A 2008 survey of Canadian and American sex therapists
Sex therapy is a strategy for the improvement of sexual function and treatment of sexual dysfunction. This includes sexual dysfunctions such as premature ejaculation or delayed ejaculation, erectile dysfunction, lack of sexual interest or arousal ...
stated that the average time for heterosexual intercourse (coitus) was 7 minutes and that 1 to 2 minutes was too short, 3 to 7 minutes was adequate and 7 to 13 minutes desirable, while 10 to 30 minutes was too long.
Anorgasmia
Anorgasmia is a type of sexual dysfunction in which a person cannot achieve orgasm despite adequate stimulation. Anorgasmia is far more common in females (4.6 percent) than in males and is especially rare in younger men. The problem is greater in ...
is regular difficulty reaching orgasm after ample sexual stimulation, causing personal distress. This is significantly more common in women than in men, which has been attributed to the lack of sex education
Sex education, also known as sexual education, sexuality education or sex ed, is the instruction of issues relating to human sexuality, including emotional relations and responsibilities, human sexual anatomy, Human sexual activity, sexual acti ...
with regard to women's bodies, especially in sex-negative
The sex-positive movement is a social movement, social and philosophical movement that seeks to change cultural attitudes and norms around sexuality, promoting the recognition of sexuality (in the countless forms of expression) as a natural and he ...
cultures, such as clitoral stimulation usually being key for women to orgasm. The physical structure of coitus favors penile stimulation over clitoral stimulation; the location of the clitoris then usually necessitates manual or oral stimulation in order for the woman to achieve orgasm. Approximately 25% of women report difficulties with orgasm, 10% of women have never had an orgasm, and 40% or 40–50% have either complained about sexual dissatisfaction or experienced difficulty becoming sexually aroused at some point in their lives.
Vaginismus
Vaginismus is a condition in which involuntary muscle spasm interferes with vaginal intercourse or other penetration of the vagina. This often results in pain with attempts at sex. Often, it begins when vaginal intercourse is first attempted.
...
is involuntary tensing of the pelvic floor musculature, making coitus, or any form of penetration of the vagina, distressing, painful and sometimes impossible for women. It is a conditioned reflex of the pubococcygeus muscle, and is sometimes referred to as the ''PC muscle.'' Vaginismus can be hard to overcome because if a woman expects to experience pain during sexual intercourse, this can cause a muscle spasm, which results in painful sexual intercourse. Treatment of vaginismus often includes both psychological and behavioral techniques, including the use of vaginal dilators. Additionally, the use of Botox
Botulinum toxin, or botulinum neurotoxin (BoNT), is a neurotoxic protein produced by the bacterium ''Clostridium botulinum'' and related species. It prevents the release of the neurotransmitter acetylcholine from axon endings at the neurom ...
as a medical treatment for vaginismus has been tested and administered. Painful or uncomfortable sexual intercourse may also be categorized as dyspareunia
Dyspareunia ( ) is painful sexual intercourse due to medical or psychological causes. The term ''dyspareunia'' covers both female dyspareunia and male dyspareunia, but many discussions that use the term without further specification concern the f ...
.
Approximately 40% of males reportedly have some form of erectile dysfunction
Erectile dysfunction (ED), also called impotence, is the type of sexual dysfunction in which the penis fails to become or stay erect during sexual activity. It is the most common sexual problem in men.Cunningham GR, Rosen RC. Overview of male ...
(ED) or impotence, at least occasionally. Premature ejaculation has been reported to be more common than erectile dysfunction, although some estimates suggest otherwise. Due to various meanings of the disorder, estimates for the prevalence of premature ejaculation vary significantly more than for erectile dysfunction. For example, the Mayo Clinic
The Mayo Clinic () is a nonprofit American academic medical center focused on integrated health care, education, and research. It employs over 4,500 physicians and scientists, along with another 58,400 administrative and allied health staff, ...
states, "Estimates vary, but as many as 1 out of 3 men may be affected by remature ejaculationat some time." Further, "Masters and Johnson speculated that premature ejaculation is the most common sexual dysfunction, even though more men seek therapy for erectile difficulties" and that this is because "although an estimated 15 percent to 20 percent of men experience difficulty controlling rapid ejaculation, most do not consider it a problem requiring help, and many women have difficulty expressing their sexual needs". The American Urological Association
The American Urological Association (AUA) is a professional association in the United States for urology professionals. It has its headquarters at the William P. Didusch Center for Urologic History in Maryland.
AUA works with many international o ...
(AUA) estimates that premature ejaculation could affect 21 percent of men in the United States.
For those whose impotence is caused by medical conditions, prescription drugs such as Viagra
Sildenafil, sold under the brand name Viagra, among others, is a medication used to treat erectile dysfunction and pulmonary arterial hypertension. It is unclear if it is effective for treating sexual dysfunction in women. It is taken by ...
, Cialis
Tadalafil, sold under the brand name Cialis among others, is a medication used to treat erectile dysfunction (ED), benign prostatic hyperplasia (BPH), and pulmonary arterial hypertension. It is taken by mouth. Onset is typically within half ...
, and Levitra are available. However, doctors caution against the unnecessary use of these drugs because they are accompanied by serious risks such as increased chance of heart attack. The selective serotonin reuptake inhibitor
Selective serotonin reuptake inhibitors (SSRIs) are a class of drugs that are typically used as antidepressants in the treatment of major depressive disorder, anxiety disorders, and other psychological conditions.
SSRIs increase the extracell ...
(SSRI) and antidepressant drug dapoxetine
Dapoxetine, marketed as Priligy, among others, is a medication used for the treatment of premature ejaculation (PE) in men 18–64 years old. Dapoxetine works by inhibiting the serotonin transporter, increasing serotonin's action at the postsynap ...
has been used to treat premature ejaculation. In clinical trials, those with PE who took dapoxetine experienced sexual intercourse three to four times longer before orgasm than without the drug. Another ejaculation-related disorder is delayed ejaculation
Delayed ejaculation (DE) describes a man's inability or persistent difficulty in achieving orgasm, despite typical sexual desire and sexual stimulation. Generally, a man can reach orgasm within a few minutes of active thrusting during sexual inter ...
, which can be caused as an unwanted side effect of antidepressant medications such as fluvoxamine
Fluvoxamine, sold under the brand name Luvox and Faverin among others, is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class. It is primarily used to treat major depressive disorder and obsessive–compulsive disorder ...
; however, all SSRIs have ejaculation-delaying effects, and fluvoxamine has the least ejaculation-delaying effects.
Sexual intercourse remains possible after major medical treatment of the reproductive organs and structures. This is especially true for women. Even after extensive gynecological surgical procedures (such as hysterectomy
Hysterectomy is the surgical removal of the uterus. It may also involve removal of the cervix, ovaries (oophorectomy), Fallopian tubes (salpingectomy), and other surrounding structures.
Usually performed by a gynecologist, a hysterectomy may b ...
, oophorectomy
Oophorectomy (; from Greek , , 'egg-bearing' and , , 'a cutting out of'), historically also called ''ovariotomy'' is the surgical removal of an ovary or ovaries. The surgery is also called ovariectomy, but this term is mostly used in reference to ...
, salpingectomy
Salpingectomy refers to the surgical removal of a Fallopian tube. This may be done to treat an ectopic pregnancy or cancer, to prevent cancer, or as a form of contraception.
This procedure is now sometimes preferred over its ovarian tube-sparin ...
, dilation and curettage
Dilation (or dilatation) and curettage (D&C) refers to the dilation (widening/opening) of the cervix and surgical removal of part of the lining of the uterus and/or contents of the uterus by scraping and scooping (curettage). It is a gynecologic ...
, hymenotomy
A hymenotomy is a medical procedure involving the surgery, surgical removal or opening of the hymen. It is often performed on patients with an imperforate hymen, imperforate or Hymen#Anatomic variations, septate hymen, or other situations where th ...
, Bartholin gland
The Bartholin's glands (named after Caspar Bartholin the Younger; also called Bartholin glands or greater vestibular glands) are two pea sized compound alveolar glandsManual of Obstetrics. (3rd ed.). Elsevier. pp. 1-16. . located slightly poster ...
surgery, abscess removal, vestibulectomy A vestibulectomy is a gynecological surgical procedure that can be used to treat vulvar pain, specifically in cases of provoked vestibulodynia. Vestibulodynia (vulvar vestibulitis) is a chronic pain syndrome that is a subtype of localized vulvo ...
, labia minora
The labia minora (Latin for 'smaller lips', singular: ''labium minus'', 'smaller lip'), also known as the inner labia, inner lips, vaginal lips or nymphae are two flaps of skin on either side of the human vaginal opening in the vulva, situated be ...
reduction, cervical conization
Cervical conization ( CPT codes 57520 (Cold Knife) and 57522 (Loop Excision)) refers to an excision of a cone-shaped sample of tissue from the mucous membrane of the cervix. Conization may be used for either diagnostic purposes as part of a biopsy ...
, surgical
Surgery ''cheirourgikē'' (composed of χείρ, "hand", and ἔργον, "work"), via la, chirurgiae, meaning "hand work". is a medical specialty that uses operative manual and instrumental techniques on a person to investigate or treat a pat ...
and radiological cancer treatments and chemotherapy), coitus can continue. Reconstructive surgery remains an option for women who have experienced benign and malignant conditions.
Disabilities and other complications
Obstacles that those with disabilities
Disability is the experience of any condition that makes it more difficult for a person to do certain activities or have equitable access within a given society. Disabilities may be cognitive, developmental, intellectual, mental, physical, se ...
face with regard to engaging in sexual intercourse include pain, depression, fatigue, negative body image
Body image is a person's thoughts, feelings and perception of the aesthetics or sexual attractiveness of their own body. The concept of body image is used in a number of disciplines, including neuroscience, psychology, medicine, psychiatry, ps ...
, stiffness, functional impairment, anxiety, reduced libido
Libido (; colloquial: sex drive) is a person's overall sexual drive or desire for sexual activity. Libido is influenced by biological, psychological, and social factors. Biologically, the sex hormones and associated neurotransmitters that act up ...
, hormonal imbalance, and drug treatment or side effects. Sexual functioning has been regularly identified as a neglected area of the quality of life in patients with rheumatoid arthritis
Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and hands are involv ...
. For those that must take opioids for pain control, sexual intercourse can become more difficult. Having a stroke
A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...
can also largely impact on the ability to engage in sexual intercourse. Although disability-related pain, including as a result of cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
, and mobility impairment can hamper sexual intercourse, in many cases, the most significant impediments to sexual intercourse for individuals with a disability are psychological. In particular, people who have a disability can find sexual intercourse daunting due to issues involving their self-concept
In the psychology of self, one's self-concept (also called self-construction, self-identity, self-perspective or self-structure) is a collection of beliefs about oneself. Generally, self-concept embodies the answer to the question ''"Who am I? ...
as a sexual being, or a partner's discomfort or perceived discomfort. Temporary difficulties can arise with alcohol and sex
Alcohol and sex deals with the effects of the consumption of alcohol on sexual behavior. The effects of alcohol are balanced between its suppressive effects on sexual physiology, which will decrease sexual activity, and its suppression of psycholo ...
, as alcohol can initially increase interest through disinhibition but decrease capacity with greater intake; however, disinhibition can vary depending on the culture.
People with mental disabilities
Mental may refer to:
* of or relating to the mind
Films
* ''Mental'' (2012 film), an Australian comedy-drama
* ''Mental'' (2016 film), a Bangladeshi romantic-action movie
* ''Mental'', a 2008 documentary by Kazuhiro Soda
* ''Mental'', a 2014 Od ...
also are subject to challenges in participating in sexual intercourse. Women with intellectual disabilities (ID) are often presented with situations that prevent sexual intercourse. This can include the lack of a knowledgeable healthcare provider trained and experienced in counseling those with ID on sexual intercourse. Those with ID may have hesitations regarding the discussion of the topic of sex, a lack of sexual knowledge and limited opportunities for sex education. In addition there are other barriers such as a higher prevalence of sexual abuse and assault. These crimes often remain underreported. There remains a lack of "dialogue around this population's human right to consensual sexual expression, undertreatment of menstrual disorders, and legal and systemic barriers". Women with ID may lack sexual health care and sex education. They may not recognize sexual abuse. Consensual sexual intercourse is not always an option for some. Those with ID may have limited knowledge and access to contraception, screening for sexually transmitted infections and cervical cancer.
Social effects
Adults
Sexual intercourse may be for reproductive, relational, or recreational purposes. It often plays a strong role in human bonding
Human bonding is the process of development of a close, interpersonal relationship between two or more people. It most commonly takes place between family members or friends, but can also develop among groups, such as sporting teams and whenever ...
. In many societies, it is normal for couples to have sexual intercourse while using some method of birth control, sharing pleasure and strengthening their emotional bond through sexual activity even though they are deliberately avoiding pregnancy.
In humans and bonobo
The bonobo (; ''Pan paniscus''), also historically called the pygmy chimpanzee and less often the dwarf chimpanzee or gracile chimpanzee, is an endangered great ape and one of the two species making up the genus '' Pan,'' the other being the comm ...
s, the female undergoes relatively concealed ovulation Concealed ovulation or hidden œstrus in a species is the lack of any perceptible change in an adult female (for instance, a change in appearance or scent) when she is fertile and near ovulation. Some examples of perceptible changes are swelling an ...
so that male and female partners commonly do not know whether she is fertile at any given moment. One possible reason for this distinct biological feature may be formation of strong emotional bonds between sexual partners important for social interactions and, in the case of humans, long-term partnership rather than immediate sexual reproduction.
Sexual dissatisfaction
Sexual frustration is a sense of dissatisfaction stemming from a discrepancy between a person's desired and achieved sexual activity. It may result from physical, mental, emotional, social, and religious or spiritual barriers. It may also derive ...
due to the lack of sexual intercourse is associated with increased risk of divorce
Divorce (also known as dissolution of marriage) is the process of terminating a marriage or marital union. Divorce usually entails the canceling or reorganizing of the legal duties and responsibilities of marriage, thus dissolving the ...
and relationship dissolution, especially for men. Some research, however, indicates that general dissatisfaction with marriage
Marriage, also called matrimony or wedlock, is a culturally and often legally recognized union between people called spouses. It establishes rights and obligations between them, as well as between them and their children, and between ...
for men results if their wives flirted
Flirting or coquetry is a social and sexual behavior involving spoken or written communication, as well as body language. It is either to suggest interest in a deeper relationship with the other person or, if done playfully, for amusement.
It ...
with, erotically kissed or became romantically or sexually involved with another man (infidelity
Infidelity (synonyms include cheating, straying, adultery, being unfaithful, two-timing, or having an affair) is a violation of a couple's emotional and/or sexual exclusivity that commonly results in feelings of anger, sexual jealousy, and riva ...
), and that this is especially the case for men with a lower emotional and composite marital satisfaction. Other studies report that the lack of sexual intercourse does not significantly result in divorce, though it is commonly one of the various contributors to it. According to the 2010 National Survey of Sexual Health and Behavior (NSSHB), men whose most recent sexual encounter was with a relationship partner reported greater arousal, greater pleasure, fewer problems with erectile function, orgasm, and less pain during the event than men whose last sexual encounter was with a non-relationship partner.
For women, there is often a complaint about the lack of their spouses' sexual spontaneity. Decreased sexual activity among these women may be the result of their perceived failure to maintain ideal physical attractiveness
Physical attractiveness is the degree to which a person's physical features are considered aesthetically pleasing or beautiful. The term often implies sexual attractiveness or desirability, but can also be distinct from either. There are many ...
or because their sexual partners' health issues have hindered sexual intercourse. Some women express that their most satisfying sexual experiences entail being connected to someone, rather than solely basing satisfaction on orgasm. With regard to divorce, women are more likely to divorce their spouses for a one-night stand
A one-night stand or one-night sex is a single sexual encounter in which there is an expectation that there shall be no further relations between the sexual participants. It draws its name from the common practice of a one-night stand, a single ...
or various infidelities if they are in less cooperative or high-conflict marriages.
Research additionally indicates that non-married couples who are cohabiting
Cohabitation is an arrangement where people who are not married, usually couples, live together. They are often involved in a romantic or sexually intimate relationship on a long-term or permanent basis. Such arrangements have become increas ...
engage in sexual intercourse more often than married couples, and are more likely to participate in sexual activity outside of their sexual relationships; this may be due to the "honeymoon
A honeymoon is a vacation taken by newlyweds immediately after their wedding, to celebrate their marriage. Today, honeymoons are often celebrated in destinations considered exotic or romantic. In a similar context, it may also refer to the phase ...
" effect (the newness or novelty of sexual intercourse with the partner), since sexual intercourse is usually practiced less the longer a couple is married, with couples engaging in sexual intercourse or other sexual activity once or twice a week, or approximately six to seven times a month. Sexuality in older age
Sexuality in older age concerns the sexual drive, sexual activity, interests, orientation, intimacy, self-esteem, behaviors, and overall sexuality of people in middle age and old age, and the social perceptions concerning sexuality in older age ...
also affects the frequency of sexual intercourse, as older people generally engage in sexual intercourse less frequently than younger people do.
Adolescents
Adolescents commonly use sexual intercourse for relational and recreational purposes, which may negatively or positively impact their lives. For example, while teenage pregnancy
Teenage pregnancy, also known as adolescent pregnancy, is pregnancy in a female adolescent or young adult under the age of 20. This includes those who are legally considered adults in their country. The WHO defines adolescence as the period bet ...
may be welcomed in some cultures, it is also commonly disparaged, and research suggests that the earlier onset of puberty for children puts pressure on children and teenagers to act like adults before they are emotionally or cognitively ready. Some studies have concluded that engaging in sexual intercourse leaves adolescents, especially girls, with higher levels of stress and depression, and that girls may be likelier to engage in sexual risk (such as sexual intercourse without the use of a condom), but it may be that further research is needed in these areas. In some countries, such as the United States, sex education
Sex education, also known as sexual education, sexuality education or sex ed, is the instruction of issues relating to human sexuality, including emotional relations and responsibilities, human sexual anatomy, Human sexual activity, sexual acti ...
and abstinence-only sex education
Abstinence-only sex education is a form of sex education that teaches not having sex outside of marriage. It often excludes other types of sexual and reproductive health education, such as birth control and safe sex. Comprehensive sex education, ...
curricula are available to educate adolescents about sexual activity; these programs are controversial, as debate exists as to whether teaching children and adolescents about sexual intercourse or other sexual activity should only be left up to parents or other caregiver
A caregiver or carer is a paid or unpaid member of a person's social network who helps them with activities of daily living. Since they have no specific professional training, they are often described as informal caregivers. Caregivers most commo ...
s.
Some studies from the 1970s through 1990s suggested an association between self-esteem
Self-esteem is confidence in one's own worth or abilities. Self-esteem encompasses beliefs about oneself (for example, "I am loved", "I am worthy") as well as emotional states, such as triumph, despair, pride, and shame. Smith and Mackie (2007) d ...
and sexual intercourse among adolescents, while other studies, from the 1980s and 1990s, reported that the research generally indicates little or no relationship between self-esteem and sexual activity among adolescents. By the 1990s, the evidence mostly supported the latter, and further research has supported little or no relationship between self-esteem and sexual activity among adolescents. Scholar Lisa Arai stated, "The idea that early sexual activity and pregnancy is linked to low self-esteem became fashionable in the latter half of the 20th century, particularly in the US," adding that, "Yet, in a systematic review of the relationship between self-esteem and teenagers' sexual behaviours, attitudes and intentions (which analyzed findings from 38 publications) 62% of behavioral findings and 72% of the attitudinal findings exhibited no statistically significant associations (Goodson et al, 2006)." Studies that do find a link suggest that non-virgin boys have higher self-esteem than virgin boys and that girls who have low self-esteem and poor self-image
Self-image is the mental picture, generally of a kind that is quite resistant to change, that depicts not only details that are potentially available to an objective investigation by others (height, weight, hair color, etc.), but also items that h ...
are more prone to risk-taking behaviors, such as unprotected sex and multiple sexual partners
Multiple sex partners is the measure and incidence of engaging in sexual activities with two or more people within a specific time period. Sexual activity with MSP can happen simultaneously or serially. MSP includes sexual activity between people o ...
.
Psychiatrist Lynn Ponton Dr. Lynn Elisabeth Ponton (born 3 October 1951) is a child and adolescent psychiatrist and professor at the University of California, San Francisco. She is the author of the books '' The Sex Lives of Teenagers'' and '' The Romance of Risk''. Her wo ...
wrote, "All adolescents have sex lives, whether they are sexually active with others, with themselves, or seemingly not at all", and that viewing adolescent sexuality as a potentially positive experience, rather than as something inherently dangerous, may help young people develop healthier patterns and make more positive choices regarding sexual activity. Researchers state that long-term romantic relationships allow adolescents to gain the skills necessary for high-quality relationships later in life. Overall, positive romantic relationships among adolescents can result in long-term benefits. High-quality romantic relationships are associated with higher commitment in early adulthood, and are positively associated with social competence.
Ethical, religious, and legal views
General
While sexual intercourse, as coitus, is the natural mode of reproduction for the human species, humans have intricate moral and ethical guidelines which regulate the practice of sexual intercourse and vary according to religious
Religion is usually defined as a social system, social-cultural system of designated religious behaviour, behaviors and practices, morality, morals, beliefs, worldviews, religious text, texts, sacred site, sanctified places, prophecy, prophecie ...
and governmental laws. Some governments and religions also have strict designations of what they consider appropriate and inappropriate sexual behavior, which include restrictions on the types of sex acts which are permissible. A historically prohibited or regulated sex act is anal sex.
Sexual offenses
Sexual intercourse with a person against their will, or without their consent
Consent occurs when one person voluntarily agrees to the proposal or desires of another. It is a term of common speech, with specific definitions as used in such fields as the law, medicine, research, and sexual relationships. Consent as und ...
, is rape
Rape is a type of sexual assault usually involving sexual intercourse or other forms of sexual penetration carried out against a person without their consent. The act may be carried out by physical force, coercion, abuse of authority, or ag ...
, but may also be called ''sexual assault
Sexual assault is an act in which one intentionally sexually touches another person without that person's consent, or coerces or physically forces a person to engage in a sexual act against their will. It is a form of sexual violence, which ...
''; it is considered a serious crime
In ordinary language, a crime is an unlawful act punishable by a State (polity), state or other authority. The term ''crime'' does not, in modern criminal law, have any simple and universally accepted definition,Farmer, Lindsay: "Crime, definit ...
in most countries. More than 90% of rape victims are female, 99% of rapists male, and only about 5% of rapists are strangers to the victims.
Most countries have age of consent
The age of consent is the age at which a person is considered to be legally competent to consent to sexual acts. Consequently, an adult who engages in sexual activity with a person younger than the age of consent is unable to legally claim ...
laws which set the minimum legal age with whom an older person may engage in sexual intercourse, usually set at 16 to 18, but ranges from 12 to 20, years of age. In some societies, an age of consent is set by non-statutory custom or tradition. Sex with a person under the age of consent, regardless of their stated consent, is often considered sexual assault or statutory rape
In common law jurisdictions, statutory rape is nonforcible sexual activity in which one of the individuals is below the age of consent (the age required to legally consent to the behavior). Although it usually refers to adults engaging in sexual ...
depending on differences in ages of the participants. Some countries treat any sex with a person of diminished or insufficient mental capacity to give consent, regardless of age, as rape.
Robert Francoeur et al. stated that "prior to the 1970s, rape definitions of sex often included only penile-vaginal sexual intercourse." Authors Pamela J. Kalbfleisch and Michael J. Cody stated that this made it so that if "sex means penile-vaginal intercourse, then rape means forced penile-vaginal intercourse, and other sexual behaviors – such as fondling a person's genitals without her or his consent, forced oral sex, and same-sex coercion – are not considered rape"; they stated that "although some other forms of forced sexual contact are included within the legal category of sodomy (e.g., anal penetration and oral-genital contact), many unwanted sexual contacts have no legal grounding as rape in some states". Ken Plumber argued that the legal meaning "of rape in most countries is unlawful sexual intercourse which means the penis must penetrate the vagina" and that "other forms of sexual violence towards women such as forced oral sex or anal intercourse, or the insertion of other objects into the vagina, constitute the 'less serious' crime of sexual assault".
Over time, the meaning of rape broadened in some parts of the world to include many types of sexual penetration, including anal intercourse, fellatio, cunnilingus, and penetration of the genitals or rectum by an inanimate object. Until 2012, the Federal Bureau of Investigation
The Federal Bureau of Investigation (FBI) is the domestic intelligence and security service of the United States and its principal federal law enforcement agency. Operating under the jurisdiction of the United States Department of Justice, ...
(FBI) still considered rape a crime solely committed by men against women. In 2012, they changed the meaning from "The carnal knowledge of a female forcibly and against her will" to "The penetration, no matter how slight, of the vagina or anus with any body part or object, or oral penetration by a sex organ of another person, without the consent of the victim." The meaning does not change federal or state criminal codes or impact charging and prosecution on the federal, state or local level, but instead assures that rape will be more accurately reported nationwide. In some instances, penetration is not required for the act to be categorized as rape.
In most societies around the world, the concept of incest
Incest ( ) is human sexual activity between family members or close relatives. This typically includes sexual activity between people in consanguinity (blood relations), and sometimes those related by affinity (marriage or stepfamily), adoption ...
exists and is criminalized. James Roffee, a senior lecturer in criminology at Monash University, addressed potential harm associated with familial sexual activity, such as resulting children born with deficiencies. However, the law is more concerned with protecting the rights of people who are potentially subjected to such abuse. This is why familial sexual relationships are criminalized, even if all parties are consensual. There are laws prohibiting all kinds of sexual activity between relatives, not necessarily penetrative sex. These laws refer to grandparents, parents, children, siblings, aunts and uncles. There are differences between states in terms of the severity of punishments and what they consider to be a relative, including biological parents, step-parents, adoptive parents and half-siblings.
Another sexual matter concerning consent is zoophilia
Zoophilia is a paraphilia involving a sexual fixation on non-human animals. Bestiality is cross-species sexual activity between humans and non-human animals. The terms are often used interchangeably, but some researchers make a distinction b ...
, which is a paraphilia involving sexual activity between human and non-human animals, or a fixation on such practice. Human sexual activity with non-human animals is not outlawed in some jurisdictions, but it is illegal in others under cruelty to animals, animal abuse laws or laws dealing with crime against nature, crimes against nature.
Romantic relationships
Marriage and relationships
Sexual intercourse has traditionally been considered an essential part of a marriage, with many religious customs requiring consummation of the marriage and citing marriage as the most appropriate union for sexual reproduction (procreation). In such cases, a failure for any reason to consummate the marriage would be considered a ground for annulment (which does not require a divorce process). Sexual relations between marriage partners have been a "marital right" in various societies and religions, both historically and in modern times, especially with regard to a husband's rights to his wife. Until the late 20th century, there was usually a marital rape, marital exemption in rape laws which precluded a husband from being prosecuted under the rape law for forced sex with his wife. Author Oshisanya, 'lai Oshitokunbo stated, "As the legal status of women has changed, the concept of a married man's or woman's marital right to sexual intercourse has become less widely held."
Adultery (engaging in sexual intercourse with someone other than one's spouse) has been, and remains, a criminal offense in some jurisdictions. Sexual intercourse between unmarried partners and cohabitation of an unmarried couple are also illegal in some jurisdictions. Conversely, in other countries, marriage is not required, socially or legally, in order to have sexual intercourse or to procreate (for example, the majority of births are outside of marriage in countries such as Iceland, Norway, Sweden, Denmark, Bulgaria, Estonia, Slovenia, France, Belgium).
With regard to divorce laws, the refusal to engage in sexual intercourse with one's spouse may give rise to a grounds for divorce, which may be listed under "grounds of abandonment". Concerning no-fault divorce jurisdictions, author James G. Dwyer stated that no-fault divorce laws "have made it much easier for a woman to exit a marital relationship, and wives have obtained greater control over their bodies while in a marriage" because of legislative and judicial changes regarding the concept of a marital exemption when a man rapes his wife.
There are various legal positions regarding the meaning and legality of sexual intercourse between persons of the same sex or gender. For example, in the 2003 New Hampshire Supreme Court case Blanchflower v. Blanchflower, it was held that female same-sex sexual relations, and same-sex sexual practices in general, did not constitute sexual intercourse, based on a 1961 entry in ''Webster's Third New International Dictionary'' that categorizes sexual intercourse as coitus; and thereby an accused wife in a divorce case was found not guilty of adultery
Adultery (from Latin ''adulterium'') is extramarital sex that is considered objectionable on social, religious, moral, or legal grounds. Although the sexual activities that constitute adultery vary, as well as the social, religious, and legal ...
. Some countries consider same-sex sexual behavior an offense punishable by imprisonment or execution; this is the case, for example, LGBT in Islam, in Islamic countries, including LGBT rights in Iran, LGBT issues in Iran.
Opposition to same-sex marriage is largely based on the belief that sexual intercourse and sexual orientation should be of a heterosexual nature. The recognition of such marriages is a civil rights, political, social, moral and religious issue in many nations, and the conflicts arise over whether same-sex couples should be allowed to enter into marriage, be required to use a different status (such as a civil union, which either grant equal rights as marriage or limited rights in comparison to marriage), or not have any such rights. A related issue is whether the word ''marriage'' should be applied.
Religious views
There are wide differences in religious views with regard to sexual intercourse in or outside of marriage:
*Most denominations of Christianity, including Catholicism, have strict views or rules on what sexual practices are and are not acceptable. Most Christian views on sexual intercourse are influenced by various interpretations of the Bible. Sexual intercourse outside of marriage, for example, is considered a sin in some churches; in such cases, sexual intercourse may be called a sacred covenant, holy, or a holy sacrament between husband and wife. Historically, Christian teachings often promoted celibacy, although today usually only certain members (for example, certain celibacy of the clergy, religious leaders) of some groups take a vow of celibacy, forsaking both marriage and any type of sexual or romantic activity. The Bible may be interpreted as endorsing penile-vaginal penetration as the only form of acceptable sexual activity, while other interpretations view the Bible as not being clear on oral sex or other particular sexual behaviors and that it is a personal decision as to whether oral sex is acceptable within marriage. Some sects consider the use of birth control to prevent sexual reproduction a grave sin against God and marriage, as they believe that the main purpose of marriage, or one of its primary purposes, is to produce children, while other sects do not hold such beliefs. The Bible also prohibits sexual intercourse during menstruation
Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. The menstrual cycle is characterized by the rise and fall of hor ...
.
** In the Roman Catholic Church, if a matrimonial celebration takes place (ratification), but the spouses have not yet engaged in intercourse (consummation), then the marriage is considered to be a marriage via ''ratum sed non consummatum''. Such a marriage, regardless of the reason for non-consummation, can be dissolved by the pope.
** In the Church of Jesus Christ of Latter-day Saints (LDS Church) sexual relations within the bonds of matrimony are seen as sacred. Latter-day Saints consider sexual relations to be ordained of God for the creation of children and for the expression of love between husband and wife. Members are discouraged from having any sexual relations before marriage, and from being unfaithful to their spouses after marriage.
** Shakers believe that sexual intercourse is the root of all sin and that all people should therefore be celibate, including married couples. The original Shaker community that peaked at 6,000 full members in 1840 dwindled to Sister June Carpenter, three members by 2009.
* In Judaism, a married Jewish man is required to provide his wife with sexual pleasure called ''onah'' (literally, "her time"), which is one of the conditions he takes upon himself as part of the Jewish marriage contract, ''ketubah'', that he gives her during the Jewish wedding ceremony. In Jewish views on marriage, sexual desire is not evil, but must be satisfied in the proper time, place and manner.
* Islam views sex within marriage as something pleasurable, a spiritual activity, and a duty.[Abdul Rahman bin Abdul Karim al-Sheha. Islamic Perspective of Sex (2003) Saudi Arabia. ][Fatima M. D'Oyen. The Miracle of Life. (2007) Islamic Foundation (UK). ] In Shia Islam, men are allowed to enter into an unlimited number of temporary marriages, which are contracted to last for a period of minutes to multiple years and permit sexual intercourse. Shia women are allowed to enter only one marriage at a time, whether temporary or permanent.
* Hinduism has varied views about sexuality,[Don S. Browning, Martha Christian Green, John Witte. Sex, marriage, and family in world religions. (2006) Columbia University Press.]
/ref> but according to the Kama Sutra, ''sex'' is considered as a normal activity that is necessary for a fulfilling and happy life.
* Buddhism, Buddhist ethics, in its most general formulation, holds that one should neither be attached to nor crave sensual pleasure since it binds one to the cycle of birth and death, samsara, and prevents one attaining the goal of Nirvana. Since Buddhist monastics (i.e. bhikshus and bhikshunis) are to be fully dedicated towards this goal, they undertake the training rule of total abstinence from sexual intercourse, i.e. of celibacy. Other monastic training rules from the Code of Discipline (Patimokkha or Pratimoksasutra) and canonical Vinaya scriptures are to prevent masturbation, lustfully touching and speaking to members of the other sex, and other forms of sexual behaviour. Buddhist lay people undertake the Five Precepts, the third of which is avoiding sexual misconduct. Peter Harvey (academic), Peter Harvey says that this precept "relates primarily to the avoidance of causing suffering by one's sexual behaviour. Adultery—'going with the wife of another'—is the most straightforward breach of this precept. The wrongness of this is seen as partly in terms of its being an expression of greed, and partly in terms of its harm to others. It is said that a man breaks the precept if he has intercourse with women who are engaged, or who are still protected by any relative, or young girls not protected by a relative, Clearly, rape and incest are breaches of the precept." The Buddhist Canonical scriptures contain no other regulations or recommendations for lay people—for example, with regards homosexuality, masturbation, sexual practices and contraceptives. However, in keeping with the Buddhist ethical principles of not-harming and avoiding shame, guilt and remorse, socially taboo forms of sexuality as well as obsessive sexual activities can also be seen as being included in the third precept. Later Buddhist authors such as Nagarjuna give various clarifications and recommendations.
* In the Baháʼí Faith, sexual relationships are permitted only between a husband and wife.
* Unitarian Universalists, with an emphasis on strong interpersonal ethics, do not place boundaries on the occurrence of sexual intercourse among consenting adults.
* According to the Brahma Kumaris and AIVV, Prajapita Brahma Kumaris religion, the power of lust is the root of all evil and worse than murder. Purity (celibacy) is promoted for peace and to prepare for life in forthcoming Heaven on earth for 2,500 years when children will be created by the power of the mind.
* Wiccans are told, as declared within the Charge of the Goddess, to "''[l]et [the Goddess'] worship be within the heart that rejoiceth; for behold, all acts of love and pleasure are [the Goddess'] rituals.''" This statement appears to allow one freedom to explore sensuality and pleasure, and mixed with the final maxim within the Wiccan Rede—"''26. Eight words the Wiccan Rede fulfill—an' it harm none, do what ye will.''"—Wiccans are encouraged to be responsible with their sexual encounters, in whatever variety they may occur.
*Meher Baba maintained that "In the beginning of married life the partners are drawn to each other by lust as well as love; but with conscious and deliberate cooperation they can gradually lessen the element of lust and increase the element of love. Through this process of sublimation, lust ultimately gives place to deep love."
In some cases, the sexual intercourse between two people is seen as counter to religious law or doctrine. In many religious communities, including the Catholic Church and Bhikkhu, Mahayana Buddhists, religious leaders are expected to refrain from sexual intercourse in order to devote their full attention, energy, and loyalty to their religious duties.[William Skudlarek. Demythologizing Celibacy: Practical Wisdom from Christian and Buddhist Monasticism. (2008) Liturgical Press. ]
Other animals
In zoology, ''copulation'' often means the process in which a male introduces sperm into the female's body, especially directly into her reproductive tract. Spiders have separate male and female sexes. Before mating and copulation, the male spider spins a small web and ejaculates on to it. He then stores the sperm in reservoirs on his large pedipalps, from which he transfers sperm to the female's genitals. The females can store sperm indefinitely.
Many animals that live in water use external fertilization, whereas internal fertilization may have developed from a need to maintain gametes in a liquid medium in the Late Ordovician epoch. Internal fertilization with many vertebrates (such as reptiles, some fish, and most birds) occur via cloaca
In animal anatomy, a cloaca ( ), plural cloacae ( or ), is the posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles and birds, a ...
l copulation (see also hemipenis), while mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
s copulate vaginally, and many primitive (biology), basal vertebrates reproduce sexually with external fertilization.
For primitive insects, the male deposits spermatozoon, spermatozoa on the substrate, sometimes stored within a special structure; courtship involves inducing the female to take up the sperm package into her genital opening, but there is no actual copulation. In groups that have reproduction similar to spiders, such as Dragonfly, dragonflies, males extrude sperm into secondary copulatory structures removed from their genital opening, which are then used to inseminate the female. In dragonflies, it is a set of modified Sternum (arthropod anatomy), sternites on the second abdominal segment. In advanced groups of insects, the male uses its aedeagus, a structure formed from the terminal segments of the abdomen, to deposit sperm directly (though sometimes in a capsule called a ''spermatophore'') into the female's reproductive tract.
Bonobos, chimpanzees and dolphins are species known to engage in heterosexual behaviors even when the female is not in estrus, which is a point in her reproductive cycle suitable for successful impregnation. These species are also known to Homosexual behavior in animals, engage in same-sex sexual behaviors. In these animals, the use of sexual intercourse has evolved beyond reproduction to apparently serve additional social functions (such as bonding).
See also
*Human sexual response cycle
*Mammary intercourse
References
External links
The International Encyclopedia of Sexuality
* Janssen, D. F.
''Growing Up Sexually. Volume I. World Reference Atlas''
Advantages of Sexual Reproduction
* wikt:WikiSaurus:sexual intercourse, Synonyms for sexual intercourse – the Wiktionary, WikiSaurus list of synonyms and slang words for sexual intercourse in many languages
{{DEFAULTSORT:Sexual Intercourse
Fertility
Interpersonal relationships
Human reproduction
Mating
Sexology
Sexual acts, Intercourse
Health risk