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Body hair, or androgenic hair, is the terminal hair that develops on the
human body The human body is the structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organ systems. They ensure homeostasis and the viability of the human body. It comprises a head ...
during and after puberty. It is differentiated from the
head hair Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals. The human body, apart from areas of glabrous skin, is covered in follicles which produce thick terminal and fin ...
and less visible vellus hair, which is much finer and lighter in color. The growth of androgenic hair is related to the level of
androgen An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This incl ...
s (often referred to as male hormones) and the density of androgen receptors in the dermal papillae. Both must reach a threshold for the proliferation of hair follicle cells. From childhood onward, regardless of
sex Sex is the trait that determines whether a sexually reproducing animal or plant produces male or female gametes. Male plants and animals produce smaller mobile gametes (spermatozoa, sperm, pollen), while females produce larger ones (ova, ...
, vellus hair covers almost the entire area of the
human body The human body is the structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organ systems. They ensure homeostasis and the viability of the human body. It comprises a head ...
. Exceptions include the lips, the backs of the ears, palms of hands, soles of the feet, certain external genital areas, the navel, and scar tissue. The density of hair – i.e. the number of
hair follicle The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction between h ...
s per unit area of skin – varies from person to person. In many cases, areas on the human body that contain vellus hair will begin to produce darker and thicker body hair during puberty, such as the first growth of beard hair on a male and female adolescent's previously smooth chin; although it may appear thinner on the female. Androgenic hair follows the same growth pattern as the hair that grows on the scalp, but with a shorter
anagen phase The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction between h ...
and longer telogen phase. While the anagen phase for the hair on one's head lasts for years, the androgenic hair growth phase for body hair lasts a few months. The telogen phase for body hair lasts close to a year. This shortened growing period and extended dormant period explains why the hair on the head tends to be much longer than other hair found on the body. Differences in length seen in comparing the hair on the back of the hand and pubic hair, for example, can be explained by varied growth cycles in those two regions. The same goes for differences in body hair length seen in different people, especially when comparing
men A man is an adult male human. Prior to adulthood, a male human is referred to as a boy (a male child or adolescent). Like most other male mammals, a man's genome usually inherits an X chromosome from the mother and a Y chromos ...
and women.


Distribution

Like much of the hair on the human body, leg, arm, chest, and back hair begin as vellus hair. As people age, the hair in these regions will often begin to grow darker and more abundantly. This will typically happen during or after puberty. Men will often have more abundant, coarser hair on the arms and back, while women tend to have a less drastic change in the hair growth in these areas but do experience a significant change in thickness of hairs. However, some women will grow darker, longer hair in one or more of these regions.


Chest and abdomen

Vellus hair grows on the chest and abdomen of both sexes at all stages of development. After puberty and extending into adulthood, most males grow increasing amounts of terminal hair over the
chest The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the crea ...
and
abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...
areas. Adult women also typically can grow terminal hairs around the
areola The human areola (''areola mammae'', or ) is the pigmented area on the breast around the nipple. Areola, more generally, is a small circular area on the body with a different histology from the surrounding tissue, or other small circular ...
though in many cultures these hairs are typically removed.


Arms

Arm hair grows on a human's
forearms The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is most often used to describe the entire appendage of the upper limb, but which in anat ...
, sometimes even on the elbow area, and rarely on a human's bicep, triceps, and/or shoulders. Terminal arm hair is concentrated on the wrist end of the forearm, extending over the
hand A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the koala (which has two opposable thumbs on each " ...
. Terminal hair growth in adolescent males is often much more intense than that in females, particularly for individuals with dark hair. In some cultures, it is common for women to remove arm hair, though this practice is less frequent than that of leg hair removal. Terminal hair growth on
arm In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between th ...
s is a secondary sexual characteristic in boys and appears in the last stages of puberty. Vellus arm hair is usually concentrated on the elbow end of the forearm and often ends on the lower part of the upper arm. This type of intense arm vellus hair growth sometimes occurs in girls and children of both sexes until puberty. Even though this causes the arms to appear hairy, it is not caused solely by testosterone. The hair is softer and different from terminal arm hair, in texture.


Feet

Visible hair appearing on the top surfaces of the feet and
toes Toes are the digits (fingers) of the foot of a tetrapod. Animal species such as cats that walk on their toes are described as being ''digitigrade''. Humans, and other animals that walk on the soles of their feet, are described as being ''plan ...
generally begins with the onset of puberty. Terminal hair growth on the feet is typically more intense in adult and adolescent males than in females.


Legs

Leg hair sometimes appears at the onset of adulthood, with the legs of men more often hairier than those of women. For a variety of reasons, people may shave their leg hair, including cultural practice or individual needs. Around the world, women generally shave their leg hair more regularly than men, to conform with the social norms of many cultures, many of which perceive smooth skin as a sign of youth, beauty, and in some cultures, hygiene. However, athletes of both sexes –
swimmers Swimming is the self-propulsion of a person through water, or other liquid, usually for recreation, sport, exercise, or survival. Locomotion is achieved through coordinated movement of the limbs and the body to achieve hydrodynamic thrust that r ...
, runners,
cyclists Cycling, also, when on a two-wheeled bicycle, called bicycling or biking, is the use of cycles for transport, recreation, exercise or sport. People engaged in cycling are referred to as "cyclists", "bicyclists", or "bikers". Apart from two ...
and bodybuilders in particular – may shave their androgenic hair to reduce friction, highlight muscular development or to make it easier to get into and out of skin-tight clothing.


Pubic

Pubic hair is a collection of coarse hair found in the pubic region. It will often also grow on the thighs and abdomen. Zoologist
Desmond Morris Desmond John Morris FLS ''hon. caus.'' (born 24 January 1928) is an English zoologist, ethologist and surrealist painter, as well as a popular author in human sociobiology. He is known for his 1967 book ''The Naked Ape'', and for his telev ...
disputes theories that it developed to signal sexual maturity or protect the skin from chafing during copulation, and prefers the explanation that pubic hair acts as a scent trap. Also, both sexes having thick pubic hairs act as a partial cushion during intercourse. The genital area of males and females are first inhabited by shorter, lighter vellus hairs that are next to invisible and only begin to develop into darker, thicker pubic hair at puberty. At this time, the
pituitary gland In vertebrate anatomy, the pituitary gland, or hypophysis, is an endocrine gland, about the size of a chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The hypoph ...
secretes
gonadotropin Gonadotropins are glycoprotein hormones secreted by gonadotropic cells of the anterior pituitary of vertebrates. This family includes the mammalian hormones follicle-stimulating hormone (FSH) and luteinizing hormone (LH), the placental/chorionic ...
hormones which trigger the production of testosterone in the testicles and ovaries, promoting pubic hair growth. The average ages pubic hair begins to grow in males and females are 12 and 11, respectively. However, in some females, pubic hair has been known to start growing as early as age 7. Just as individual people differ in scalp hair color, they can also differ in pubic hair color. Differences in thickness, growth rate, and length are also evident.


Axillary

Underarm hair normally starts to appear at the beginning of puberty, with growth usually completed by the end of the teenage years. Today in much of the world, it is common for women to regularly shave their underarm hair. The prevalence of this practice varies widely, though. The practice became popular for cosmetic reasons around 1915 in the United States and United Kingdom, when one or more magazines showed a woman in a dress with shaved underarms. Regular shaving became feasible with the introduction of the
safety razor A safety razor is a shaving implement with a protective device positioned between the edge of the blade and the skin. The initial purpose of these protective devices was to reduce the level of skill needed for injury-free shaving, thereby reduc ...
at the beginning of the 20th century. While underarm shaving was quickly adopted in some English speaking countries, especially in the US and Canada, it did not become widespread in Europe until well after World War II. Since then the practice has spread worldwide; some men also choose to shave their armpits.


Facial

Facial hair grows primarily on or around one's face. Both men and women experience facial hair growth. Like pubic hair, non-vellus facial hair will begin to grow in around puberty. Moustaches in young men usually begin to grow in at around the age of puberty, although some men may not grow a moustache until they reach late teens or at all. In some cases facial hair development may take longer to mature than the late teens, and some men experience no facial hair development even at an older age. It is common for many women to develop a few facial hairs under or around the chin, along the sides of the face (in the area of sideburns), or on the upper lip. These may appear at any age after puberty but are often seen in women after
menopause Menopause, also known as the climacteric, is the time in women's lives when menstrual periods stop permanently, and they are no longer able to bear children. Menopause usually occurs between the age of 47 and 54. Medical professionals often ...
due to decreased levels of estrogen. A darkening of the vellus hair of the upper lip in women is not considered true facial hair, though it is often referred to as a "moustache"; the appearance of these dark vellus hairs may be lessened by bleaching. A relatively small number of women are able to grow enough facial hair to have a distinct beard. In some cases, female beard growth is the result of a hormonal imbalance (usually
androgen An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This incl ...
excess), or a rare genetic disorder known as
hypertrichosis Hypertrichosis is an abnormal amount of hair growth over the body. The two distinct types of hypertrichosis are generalized hypertrichosis, which occurs over the entire body, and localized hypertrichosis, which is restricted to a certain area. H ...
. Sometimes it is caused by use of
anabolic steroid Anabolic steroids, also known more properly as anabolic–androgenic steroids (AAS), are steroidal androgens that include natural androgens like testosterone as well as synthetic androgens that are structurally related and have similar effects t ...
s. Cultural pressure leads most women to remove facial hair, as it may be viewed as a social stigma.


Development

Hair follicles are to varying degrees sensitive to androgens, primarily
testosterone Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristic ...
and its derivatives, particularly
dihydrotestosterone Dihydrotestosterone (DHT, 5α-dihydrotestosterone, 5α-DHT, androstanolone or stanolone) is an endogenous androgen sex steroid and hormone. The enzyme 5α-reductase catalyzes the formation of DHT from testosterone in certain tissues includi ...
, with different areas on the body having different sensitivity. As androgen levels increase, the rate of hair growth and the weight of the hairs increase. Genetic factors determine both individual levels of androgen and the hair follicle's sensitivity to androgen, as well as other characteristics such as hair colour, type of hair and hair retention. Rising levels of androgens during puberty cause vellus hair to transform into terminal hair over many areas of the body. The sequence of appearance of terminal hair reflects the level of androgen sensitivity, with
pubic hair Pubic hair is terminal body hair that is found in the genital area of adolescent and adult humans. The hair is located on and around the sex organs and sometimes at the top of the inside of the thighs. In the pubic region around the pubis bon ...
being the first to appear due to the area's special sensitivity to androgen. The appearance of pubic hair in both sexes is usually seen as an indication of the start of a person's puberty. There is a
sexual differentiation Sexual differentiation is the process of development of the sex differences between males and females from an undifferentiated zygote. Sex determination is often distinct from sex differentiation; sex determination is the designation for the deve ...
in the amount and distribution of androgenic hair, with men tending to have more terminal hair in more areas. This includes facial hair, chest hair,
abdominal hair Abdominal hair is the hair that grows on the abdomen of humans and non-human mammals, in the region between the pubic area and the thorax (chest). The growth of abdominal hair follows the same pattern on nearly all mammals, vertically from the pu ...
,
leg hair Leg hair is hair that grows on the legs of humans, generally appearing after the onset of puberty. For aesthetic reasons and for some sports, people shave, wax, epilate, or use hair removal creams to remove the hair from their legs: see leg shav ...
, arm hair, and foot hair. (See Table 1 for development of male body hair during puberty.) Women retain more of the less visible vellus hair, although leg, arm, and foot hair can be noticeable on women. It is not unusual for women to have a few terminal hairs around their nipples as well. In the later decades of life, especially after the 5th decade, there begins a noticeable reduction in body hair especially in the legs. The reason for this is not known but it could be due to poorer circulation, lower free circulating hormone amounts or other reasons. Ref. Reynolds EL. The appearance of adult patterns of body hair in man. Ann NY Acad Sci 1951:53:576–584.


Function

Androgenic hair provides tactile sensory input by transferring hair movement and vibration via the shaft to sensory nerves within the skin. Follicular nerves detect displacement of hair shafts and other nerve endings in the surrounding skin detect vibration and distortions of the skin around the follicles. Androgenic hair extends the sense of touch beyond the surface of the skin into the air and space surrounding it, detecting air movements as well as hair displacement from contact by insects or objects.


Evolution

Determining the evolutionary function of androgenic hair must take into account both
human evolution Human evolution is the evolutionary process within the history of primates that led to the emergence of ''Homo sapiens'' as a distinct species of the hominid family, which includes the great apes. This process involved the gradual development of ...
and the thermal properties of hair itself. The thermodynamic properties of hair are based on the properties of the keratin strands and
amino acids Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...
that combine into a 'coiled' structure. This structure lends to many of the properties of hair, such as its ability to stretch and return to its original length. This coiled structure does not predispose curly or frizzy hair, both of which are defined by oval or triangular hair follicle cross-sections.


Evolution of less body hair

Hair is a very good thermal conductor and aids heat transfer both into and out of the body. When
goose bumps Goose bumps, goosebumps or goose-pimples are the bumps on a person's skin at the base of body hairs which may involuntarily develop when a person is tickled, cold or experiencing strong emotions such as fear, euphoria or sexual arousal. The ...
are observed, small muscles (
arrector pili muscle The arrector pili muscles, also known as hair erector muscles, are small muscles attached to hair follicles in mammals. Contraction of these muscles causes the hairs to stand on end, known colloquially as goose bumps (piloerection). Structure E ...
) contract to raise the hairs either to provide insulation, by reducing cooling of the skin by air convection, or in response to central nervous stimulus, similar to the feeling of 'hairs standing up on the back of your neck'. This phenomenon also occurs when static charge is built up and stored in the hair. Keratin however can easily be damaged by excessive heat and dryness, suggesting that extreme sun exposure, perhaps due to a lack of clothing, would result in perpetual hair destruction, eventually resulting in the genes being bred out in favor of high skin pigmentation. It is also true that parasites can live on and in hair thus peoples who preserved their body hair would have required greater general hygiene to prevent diseases. Markus J. Rantala of the Department of Biological and Environmental Science, University of Jyväskylä, Finland, said humans evolved by "natural selection" to be hairless when the trade off of "having fewer parasites" became more important than having a "warming, furry coat". P.E. Wheeler of the Department of Biology at Liverpool Polytechnic said
quadrupedal Quadrupedalism is a form of locomotion where four limbs are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four limbs is said to be a quadruped (from Latin ''quattuor ...
savannah A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...
mammals of similar volume to humans have body hair to keep warm while only larger quadrupedal savannah mammals lack body hair, because their body volume itself is enough to keep them warm. Therefore, Wheeler said humans who should have body hair based on predictions of body volume alone for savannah mammals evolved no body hair after evolving
bipedalism Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs or legs. An animal or machine that usually moves in a bipedal manner is known as a biped , meaning 'two feet' (from Latin ''bis'' 'double' ...
which he said reduced the amount of body area exposed to the sun by 40%, reducing the solar warming effect on the human body. Loss of fur occurred at least 2 million years ago, but possibly as early as 3.3 million years ago judging from the divergence of head and pubic lice, and aided
persistence hunting Persistence hunting is pursuit until the prey can no longer flee and succumbs to exhaustion or heat stroke. History and definition Some researchers have insisted that the point of persistence hunting is not to induce exhaustion but specifi ...
(the ability to catch prey in very long distance chases) in the warm savannas where hominins first evolved. The two main advantages are felt to be bipedal locomotion and greater thermal load dissipation capacity due to better sweating and less hair.


Sexual selection

Markus J. Rantala of the Department of Biological and Environmental Science, University of Jyväskylä, Finland, said the existence of
androgen An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This incl ...
dependent hair on men could be explained by sexual attraction whereby hair on the genitals would trap pheromones and hair on the chin would make the chin appear more massive.Rantala, M.J. (1999). Human nakedness: adaptation against ectoparasites? International Journal for Parasitology 29 1987±1989


Across populations

In 1876,
Oscar Peschel Oscar Ferdinand Peschel (17 March 1826, Dresden – 13 August 1875, Leipzig) was a German geographer and anthropologist. Biography As the son of an officer and teacher at the local military school, Peschel studied law from 1845 to 1848 in Le ...
wrote that North Asiatic Mongols, Native Americans, Malays, Hottentots and Bushmen have little to no body hair, while Semitics, Indo-Europeans, and Southern Europeans (especially the Portuguese and Spanish) have extensive body hair. Anthropologist Joseph Deniker said in 1901 that the very hirsute peoples are the
Ainu Ainu or Aynu may refer to: *Ainu people, an East Asian ethnic group of Japan and the Russian Far East * Ainu languages, a family of languages **Ainu language of Hokkaido **Kuril Ainu language, extinct language of the Kuril Islands **Sakhalin Ainu l ...
s, Uyghurs,
Iranian Iranian may refer to: * Iran, a sovereign state * Iranian peoples, the speakers of the Iranian languages. The term Iranic peoples is also used for this term to distinguish the pan ethnic term from Iranian, used for the people of Iran * Iranian lan ...
s,
Australian aborigine Aboriginal Australians are the various Indigenous peoples of the Australian mainland and many of its islands, such as Tasmania, Fraser Island, Hinchinbrook Island, the Tiwi Islands, and Groote Eylandt, but excluding the Torres Strait Island ...
s (
Arnhem Land Arnhem Land is a historical region of the Northern Territory of Australia, with the term still in use. It is located in the north-eastern corner of the territory and is around from the territory capital, Darwin. In 1623, Dutch East India Compan ...
being less hairy), Toda, Dravidians and Melanesians, while the most glabrous peoples are the American Indians, San, and
East Asian East Asia is the eastern region of Asia, which is defined in both geographical and ethno-cultural terms. The modern states of East Asia include China, Japan, Mongolia, North Korea, South Korea, and Taiwan. China, North Korea, South Korea and ...
s, who include
Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of v ...
, Mongols, and Malays. Deniker said that hirsute peoples tend to have thicker beards, eyelashes, and eyebrows but fewer hairs on their scalp. C.H. Danforth and
Mildred Trotter Mildred Trotter (February 3, 1899 – August 23, 1991) was an American pioneer as a forensic historian and forensic anthropologist. Biography Trotter was born in Monaca, Pennsylvania. She received her B.A. in zoology and physiology from Mou ...
of the Department of Anatomy at
Washington University Washington University in St. Louis (WashU or WUSTL) is a Private university, private research university with its Danforth Campus, main campus in St. Louis County, Missouri, St. Louis County, and Clayton, Missouri. Founded in 1853, the universi ...
conducted a study using army soldiers of European origin in 1922 where they concluded that dark-haired white men are generally more hairy than fair-haired white men. H. Harris, publishing in the ''British Journal of Dermatology'' in 1947, wrote American Indians have the least body hair,
Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of v ...
and
black people Black is a racialized classification of people, usually a political and skin color-based category for specific populations with a mid to dark brown complexion. Not all people considered "black" have dark skin; in certain countries, often in ...
have little body hair, white people have more body hair than black people and
Ainu Ainu or Aynu may refer to: *Ainu people, an East Asian ethnic group of Japan and the Russian Far East * Ainu languages, a family of languages **Ainu language of Hokkaido **Kuril Ainu language, extinct language of the Kuril Islands **Sakhalin Ainu l ...
have the most body hair. Anthropologist
Arnold Henry Savage Landor Arnold Henry Savage Landor (2 June 1865 – 26 December 1924) was an English painter, explorer, writer, and anthropologist. Landor wrote in an often witty style. Life and career Arnold H. S. Landor was born to Charles Savage Landor in Fl ...
, in 1970, described the
Ainu Ainu or Aynu may refer to: *Ainu people, an East Asian ethnic group of Japan and the Russian Far East * Ainu languages, a family of languages **Ainu language of Hokkaido **Kuril Ainu language, extinct language of the Kuril Islands **Sakhalin Ainu l ...
as having hairy bodies. Stewart W. Hindley and Albert Damon of the Department of Anthropology at Stanford University studied, in 1973, the frequency of hair on the middle finger joint (mid- phalangeal hair) of Solomon Islanders, as a part of a series of
anthropometric Anthropometry () refers to the measurement of the human individual. An early tool of physical anthropology, it has been used for identification, for the purposes of understanding human physical variation, in paleoanthropology and in various atte ...
studies of these populations. They summarize other studies on prevalence of this trait as reporting, in general, that
Caucasoid The Caucasian race (also Caucasoid or Europid, Europoid) is an obsolete racial classification of human beings based on a now-disproven theory of biological race. The ''Caucasian race'' was historically regarded as a biological taxon which, de ...
s are more likely to have hair on the middle finger joint than
Negroid Negroid (less commonly called Congoid) is an obsolete racial grouping of various people indigenous to Africa south of the area which stretched from the southern Sahara desert in the west to the African Great Lakes in the southeast, but also to i ...
s and
Mongoloid Mongoloid () is an obsolete racial grouping of various peoples indigenous to large parts of Asia, the Americas, and some regions in Europe and Oceania. The term is derived from a now-disproven theory of biological race. In the past, other terms ...
s, and collect the following frequencies from previously published literature: Andamanese 0%,
Eskimo Eskimo () is an exonym used to refer to two closely related Indigenous peoples: the Inuit (including the Alaska Native Iñupiat, the Greenlandic Inuit, and the Canadian Inuit) and the Yupik (or Yuit) of eastern Siberia and Alaska. A related ...
1%, African American 16% or 28%,
Ethiopians Ethiopians are the native inhabitants of Ethiopia, as well as the global diaspora of Ethiopia. Ethiopians constitute several component ethnic groups, many of which are closely related to ethnic groups in neighboring Eritrea and other parts o ...
25.6%, Mexicans of the Yucatan 20.9%,
Penobscot The Penobscot ( Abenaki: ''Pαnawάhpskewi'') are an Indigenous people in North America from the Northeastern Woodlands region. They are organized as a federally recognized tribe in Maine and as a First Nations band government in the Atlantic ...
and Shinnecock 22.7%, Gurkha 33.6%,
Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese diaspor ...
44.6%, various Hindus 40–50%, Egyptians 52.3%, Near Eastern peoples 62–71%, various Europeans 60–80%. However, they never completed an Androgenic hair map. According to anthropologist and professor
Ashley Montagu Montague Francis Ashley-Montagu (June 28, 1905November 26, 1999) — born Israel Ehrenberg — was a British-American anthropologist who popularized the study of topics such as race and gender and their relation to politics and development. He w ...
in 1989,
Asian people Asian people (or Asians, sometimes referred to as Asiatic people)United States National Library of Medicine. Medical Subject Headings. 2004. November 17, 200Nlm.nih.gov: ''Asian Continental Ancestry Group'' is also used for categorical purpos ...
and
black people Black is a racialized classification of people, usually a political and skin color-based category for specific populations with a mid to dark brown complexion. Not all people considered "black" have dark skin; in certain countries, often in ...
such as the
San people The San peoples (also Saan), or Bushmen, are members of various Khoe, Tuu, or Kxʼa-speaking indigenous hunter-gatherer cultures that are the first cultures of Southern Africa, and whose territories span Botswana, Namibia, Angola, Zambia, ...
are less hairy than white people. Montagu said that the hairless feature is a
neotenous Neoteny (), also called juvenilization,Montagu, A. (1989). Growing Young. Bergin & Garvey: CT. is the delaying or slowing of the physiological, or somatic, development of an organism, typically an animal. Neoteny is found in modern humans compare ...
trait.Montagu, Ashley. Growing Young. Published by Greenwood Publishing Group, 1989 Eike-Meinrad Winkler and Kerrin Christiansen of the Institut für Humanbiologie studied, in 1993, Kavango people and !Kung people of body hair and hormone levels to investigate the reason
black Africans Black is a racialized classification of people, usually a political and skin color-based category for specific populations with a mid to dark brown complexion. Not all people considered "black" have dark skin; in certain countries, often in ...
did not have bodies as hairy as Europeans. Winkler and Christiansen concluded the difference in hairiness between black Africans and Europeans had to do with differences in
androgen An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This incl ...
or
estradiol Estradiol (E2), also spelled oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of the estrous and menstrual female reproductive cycles. Estradiol is responsible for the development of ...
production, in androgen metabolism, and in sex hormone action in the target cells. Valerie Anne Randall of the Department of Biomedical Sciences,
University of Bradford The University of Bradford is a public research university located in the city of Bradford, West Yorkshire, England. A plate glass university, it received its royal charter in 1966, making it the 40th university to be created in Britain, bu ...
, said in 1994 beard growth in Caucasian men increases until the mid-thirties due to a delay caused by growth cycles changing from vellus hair to terminal hair. Randall said white men and women are hairier than Japanese men and women even with the same total plasma
androgen An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This incl ...
levels. Randall says that the reason for some people being hairy and some people not being hairy is unclear, but that it probably is related to differing sensitivity of
hair follicle The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction between h ...
s to
5α-reductase 5α-Reductases, also known as 3-oxo-5α-steroid 4-dehydrogenases, are enzymes involved in steroid metabolism. They participate in three metabolic pathways: bile acid biosynthesis, androgen and estrogen metabolism. There are three isozymes of ...
. Rodney P.R. Dawber of the Oxford Hair Foundation said in 1997 that East Asian males have little or no facial or body hair and Dawber also said that Mediterranean males are covered with an exuberant pelage. Milkica Nešić and her colleagues from the Department of Physiology at the
University of Niš The University of Niš ( sr, Универзитет у Нишу, Univerzitet u Nišu) is a public university in Serbia. It was founded in 1965 and consists of 13 faculties with 1,492 academic staff and around 20,500 students (as of 2018–19 sch ...
, Serbia, cited prior studies in a 2010 publication as indicating that the frequency of hair on the middle finger joint (mid- phalangeal hair) in whites is significantly higher than in
Black Black is a color which results from the absence or complete absorption of visible light. It is an achromatic color, without hue, like white and grey. It is often used symbolically or figuratively to represent darkness. Black and white have of ...
populations.


Androgenic hair as biometric

It has been shown that individuals can be uniquely identified by their androgenic hair patterns. For example, even when one's particular distinguishing features such as face and tattoos are obscured, persons can still be identified by their hair on other parts of their body.Huynh, N. Q., Xu, X., Kong, A. W. K., & Subbiah, S. (2014, December). "A preliminary report on a full-body imaging system for effectively collecting and processing biometric traits of prisoners". In ''Computational Intelligence in Biometrics and Identity Management'' (CIBIM), 2014 IEEE Symposium on (pp. 167–174). IEEE.


See also

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Alopecia Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Inflammation or scarrin ...
*
Hair removal Hair removal, also known as epilation or depilation, is the deliberate removal of body hair or head hair. Hair typically grows all over the human body and can vary in thickness and length across human populations. Hair can become more visible d ...
* Hirsutism *
Human hair color Human hair color is the pigmentation of human hair follicles due to two types of melanin: eumelanin and pheomelanin. Generally, if more melanin is present, the color of the hair is darker; if less melanin is present, the hair is lighter. The ...
* Trichotillomania


References

{{DEFAULTSORT:Androgenic Hair Hair anatomy Human development Human hair