Hair is a protein filament that grows from follicles found in the
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 fine vellus hair. Most common
interest in hair is focused on hair growth, hair types, and hair care,
but hair is also an important biomaterial primarily composed of
protein, notably alpha-keratin.
Attitudes towards different hair, such as hairstyles and hair removal,
vary widely across different cultures and historical periods, but it
is often used to indicate a person's personal beliefs or social
position, such as their age, sex, or religion.
2.1 Root of the hair
2.2 Natural color
Human hair growth
2.4.1 Classification systems
3.3 Touch sense
3.3.1 Eyebrows and eyelashes
4.2 Evolutionary variation
4.3.1 Curly hair
4.3.2 The EDAR locus
6.1 Removal practices
6.1.4 Cutting and trimming
7 Social role
7.1 Indication of status
7.2 Religious practices
8 See also
10 External links
The word "hair" usually refers to two distinct structures:
the part beneath the skin, called the hair follicle, or, when pulled
from the skin, the bulb. This organ is located in the dermis and
maintains stem cells, which not only re-grow the hair after it falls
out, but also are recruited to regrow skin after a wound.
the shaft, which is the hard filamentous part that extends above the
skin surface. A cross section of the hair shaft may be divided roughly
into three zones.
Hair fibers have a structure consisting of several layers, starting
from the outside:
the cuticle, which consists of several layers of flat, thin cells laid
out overlapping one another as roof shingles,
the cortex, which contains the keratin bundles in cell structures that
remain roughly rod-like.
the medulla, a disorganized and open area at the fiber's center.
Each strand of hair is made up of the medulla, cortex, and cuticle.
The innermost region, the medulla, is not always present and is an
open, unstructured region. The highly structural and organized
cortex, or second of three layers of the hair, is the primary source
of mechanical strength and water uptake. The cortex contains melanin,
which colors the fiber based on the number, distribution and types of
melanin granules. The shape of the follicle determines the shape of
the cortex, and the shape of the fiber is related to how straight or
curly the hair is. People with straight hair have round hair fibers.
Oval and other shaped fibers are generally more wavy or curly. The
cuticle is the outer covering. Its complex structure slides as the
hair swells and is covered with a single molecular layer of lipid that
makes the hair repel water. The diameter of human hair varies from
0.017 to 0.18 millimeters (0.00067 to 0.00709 in). There are
two million small, tubular glands and sweat glands that produce watery
fluids that cool the body by evaporation. The glands at the opening of
the hair produce a fatty secretion that lubricates the hair.
Hair growth begins inside the hair follicle. The only "living" portion
of the hair is found in the follicle. The hair that is visible is the
hair shaft, which exhibits no biochemical activity and is considered
"dead". The base of a hair's root (the "bulb") contains the cells that
produce the hair shaft. Other structures of the hair follicle
include the oil producing sebaceous gland which lubricates the hair
and the arrector pili muscles, which are responsible for causing hairs
to stand up. In humans with little body hair, the effect results in
Root of the hair
Root of the hair
Section of skin, showing the epidermis and dermis; a hair in its
Arrector pili muscle; sebaceous glands.
[edit on Wikidata]
The root of the hair ends in an enlargement, the hair bulb, which is
whiter in color and softer in texture than the shaft, and is lodged in
a follicular involution of the epidermis called the hair follicle.
Bulb of hair layers consist of fibrous connective tissue, glassy
membrane, external root sheath, internal root sheath composed of
epithelium stratum (Henle's layer) and granular stratum (Huxley's
layer), cuticle, cortex and medulla of hair.
Human hair color
A woman with dark blonde hair, the basal color appears brown due to
higher levels of brownish eumelanin.
All natural hair colors are the result of two types of hair pigments.
Both of these pigments are melanin types, produced inside the hair
follicle and packed into granules found in the fibers.
the dominant pigment in brown hair and black hair, while pheomelanin
is dominant in red hair.
Blond hair is the result of having little
pigmentation in the hair strand.
Gray hair occurs when melanin
production decreases or stops, while poliosis is hair (and often the
skin to which the hair is attached), typically in spots, that never
possessed melanin at all in the first place, or ceased for natural
genetic reasons, generally, in the first years of life.
Human hair growth
Human hair growth
Hair grows everywhere on the external body except for mucus membranes
and glabrous skin, such as that found on the palms of the hands, soles
of the feet, and lips.
Hair follows a specific growth cycle with three distinct and
concurrent phases: anagen, catagen, and telogen phases; all three
occur simultaneously - while one strand of hair may be in the anagen
phase, another may be in the telogen phase. Each has specific
characteristics that determine the length of the hair.
The body has different types of hair, including vellus hair and
androgenic hair, each with its own type of cellular construction. The
different construction gives the hair unique characteristics, serving
specific purposes, mainly, warmth and protection.
Orange American shorthair cat.
Hair exists in a variety of textures. Three main aspects of hair
texture are the curl pattern, volume, and consistency. The derivations
of hair texture are not fully understood. All mammalian hair is
composed of keratin, so the make-up of hair follicles is not the
source of varying hair patterns. There are a range of theories
pertaining to the curl patterns of hair. Scientists have come to
believe that the shape of the hair shaft has an effect on the
curliness of the individual's hair. A very round shaft allows for
fewer disulfide bonds to be present in the hair strand. This means the
bonds present are directly in line with one another, resulting in
The flatter the hair shaft becomes, the curlier hair gets, because the
shape allows more cysteines to become compacted together resulting in
a bent shape that, with every additional disulfide bond, becomes
curlier in form. As the hair follicle shape determines curl
pattern, the hair follicle size determines thickness. While the
circumference of the hair follicle expands, so does the thickness of
the hair follicle. An individual's hair volume, as a result, can be
thin, normal, or thick. The consistency of hair can almost always be
grouped into three categories: fine, medium, and coarse. This trait is
determined by the hair follicle volume and the condition of the
strand. Fine hair has the smallest circumference, coarse hair has
the largest circumference, and medium hair is anywhere between the
other two. Coarse hair has a more open cuticle than thin or medium
hair causing it to be the most porous.
There are various systems that people use to classify their curl
patterns. Being knowledgeable of an individual's hair type is a good
start to knowing how to take care of one's hair. There is not just one
method to discovering one's hair type. Additionally it is possible,
and quite normal to have more than one kind of hair type, for instance
having a mixture of both type 3a & 3b curls.
Andre Walker system
This hair typing system is the most widely used system to classify
hair. The system was created by the hairstylist of Oprah Winfrey,
Andre Walker. According to this system there are four types of hair:
straight, wavy, curly, kinky.
Type 1 is straight hair, which reflects the most sheen and also the
most resilient hair of all of the hair types. It is hard to damage and
immensely difficult to curl this hair texture. Because the sebum
easily spreads from the scalp to the ends without curls or kinks to
interrupt its path, it is the most oily hair texture of all.
Type 2 is wavy hair, whose texture and sheen ranges somewhere between
straight and curly hair. Wavy hair is also more likely to become
frizzy than straight hair. While type A waves can easily alternate
between straight and curly styles, type B and C Wavy hair is resistant
Type 3 is curly hair known to have an S-shape. The curl pattern may
resemble a lowercase "s", uppercase "S", or sometimes an uppercase "Z"
or lowercase "z". This hair type is usually
voluminous, "climate dependent (humidity = frizz), and damage prone."
Lack of proper care causes less defined curls.
Type 4 is kinky hair, which features a tightly coiled curl pattern (or
no discernible curl pattern at all) that is often fragile with a very
high density. This type of hair shrinks when wet and because it has
fewer cuticle layers than other hair types it is more susceptible to
Andre Walker hair types
TYPE 1: Straight
Hair tends to be very soft, shiny, oily and poor at holding curls, but
difficult to damage.
Hair characterised by volume and body.
Hair tends to be bone-straight and difficult to curl. Common in Asian
TYPE 2: Wavy
Hair has definite "S" pattern and is usually receptive to a variety of
Can tend to be frizzy and a little resistant to styling.
Frizzy or very frizzy with thicker waves; often more resistant to
TYPE 3: Curly
Curly hair that usually presents a definite "S" pattern and tends to
combine thickness, fullness, body and/or frizziness.
As 3a but with tighter curling like a spiral.
TYPE 4: Kinky
Hair tends to be very fragile, tightly coiled and can feature curly
As 4a but with less visible (or no) curly patterning.
As 4a and 4b but with almost no defined curl pattern.
This is a method which classifies the hair by curl pattern,
hair-strand thickness and overall hair volume.
FIA hair classification
Straight but with a slight body wave adding some volume.
Straight with body wave and one or two visible S-waves (e.g. at nape
of neck or temples).
Loose with stretched S-waves throughout.
Shorter with more distinct S-waves (resembling e.g. braided damp
Distinct S-waves, some spiral curling.
Big, loose spiral curls.
Very ("Really") curly
Tightly coiled S-curls.
Z-patterned (tightly coiled, sharply angled)
Mostly Z-patterned (tightly kinked, less definition)
Thin strands that sometimes are almost translucent when held up to the
light. Shed strands can
be hard to see even against a contrasting background; similar to hair
found on many people of
Scandinavian descent. You can also try rolling a strand between your
thumb and index finger.
Fine hair is difficult to feel or it feels like an ultra-fine strand
Strands are neither fine nor coarse; similar to hair found on many
Caucasians. You can also try
rolling a strand between your thumb and index finger. Medium hair
feels like a cotton thread.
You can feel it, but it isn't stiff or rough. It is neither fine nor
Thick strands whose shed strands usually are easily identified against
similar to hair found on many people of Asian or Native American
descent. You can also try
rolling a strand between your thumb and index finger. Coarse hair
feels hard and wiry.
As you roll it back and forth, you may hear it.
by circumference of full-hair ponytail
circumference less than 2 inches (5 centimetres)
... from 2 to 4 inches (5 to 10 centimetres)
... more than 4 inches (10 centimetres)
Many mammals have fur and other hairs that serve different functions.
Hair provides thermal regulation and camouflage for many animals; for
others it provides signals to other animals such as warnings, mating,
or other communicative displays; and for some animals hair provides
defensive functions and, rarely, even offensive protection.
has a sensory function, extending the sense of touch beyond the
surface of the skin. Guard hairs give warnings that may trigger a
Polar bears use their fur for warmth and while their skin is black,
their transparent fur appears white and provides camouflage while
hunting and serves as protection by hiding cubs in the snow.
While humans have developed clothing and other means of keeping warm,
the hair found on the head serves primarily as a source of heat
insulation and cooling (when sweat evaporates from soaked hair) as
well as protection from ultra-violet radiation exposure. The function
of hair in other locations is debated. Hats and coats are still
required while doing outdoor activities in cold weather to prevent
frostbite and hypothermia, but the hair on the human body does help to
keep the internal temperature regulated. When the body is too cold,
the arrector pili muscles found attached to hair follicles stand up,
causing the hair in these follicles to do the same. These hairs then
form a heat-trapping layer above the epidermis. This process is
formally called piloerection, derived from the
Latin words 'pilus'
('hair') and 'erectio' ('rising up'), but is more commonly known as
'having goose bumps' in English. This is more effective in other
mammals whose fur fluffs up to create air pockets between hairs that
insulate the body from the cold. The opposite actions occur when the
body is too warm; the arrector muscles make the hair lie flat on the
skin which allows heat to leave.
In some mammals, such as hedgehogs and porcupines, the hairs have been
modified into hard spines or quills. These are covered with thick
plates of keratin and serve as protection against predators. Thick
hair such as that of the lion's mane and grizzly bear's fur do offer
some protection from physical damages such as bites and scratches.
Displacement and vibration of hair shafts are detected by hair
follicle nerve receptors and nerve receptors within the skin. Hairs
can sense movements of air as well as touch by physical objects and
they provide sensory awareness of the presence of ectoparasites.
Some hairs, such as eyelashes, are especially sensitive to the
presence of potentially harmful matter.
Eyebrows and eyelashes
Eyelashes and eyebrows help to protect the eyes from dust, dirt, and
The eyebrows provide moderate protection to the eyes from dirt, sweat
and rain. They also play a key role in non-verbal communication by
displaying emotions such as sadness, anger, surprise and excitement.
In many other mammals, they contain much longer, whisker-like hairs
that act as tactile sensors.
The eyelash grows at the edges of the eyelid and protects the eye from
dirt. The eyelash is to humans, camels, horses, ostriches etc., what
whiskers are to cats; they are used to sense when dirt, dust, or any
other potentially harmful object is too close to the eye. The eye
reflexively closes as a result of this sensation.
Hair has its origins in the common ancestor of mammals, the synapsids,
about 300 million years ago. It is currently unknown at what stage the
synapsids acquired mammalian characteristics such as body hair and
mammary glands, as the fossils only rarely provide direct evidence for
Skin impression of the belly and lower tail of a
Haptodus shows the basal synapsid stock bore
transverse rows of rectangular scutes, similar to those of a modern
crocodile. An exceptionally well-preserved skull of
Estemmenosuchus, a therapsid from the Upper Permian, shows smooth,
hairless skin with what appears to be glandular depressions,
though as a semi-aquatic species it might not have been particularly
useful to determine the integument of terrestrial species. The oldest
undisputed known fossils showing unambiguous imprints of hair are the
Callovian (late middle Jurassic)
Castorocauda and several contemporary
haramiyidans, both near-mammal cynodonts. More recently,
studies on terminal
Permian Russian coprolites may suggest that
non-mammalian synapsids from that era had fur. If this is the
case, these are the oldest hair remnants known, showcasing that fur
occurred as far back as the latest Paleozoic.
Some modern mammals have a special gland in front of each orbit used
to preen the fur, called the harderian gland. Imprints of this
structure is found in the skull of the small early mammals like
Morganucodon, but not in their cynodont ancestors like
The hairs of the fur in modern animals are all connected to nerves,
and so the fur also serves as a transmitter for sensory input. Fur
could have evolved from sensory hair (whiskers). The signals from this
sensory apparatus is interpreted in the neocortex, a chapter of the
brain that expanded markedly in animals like
Hadrocodium. The more advanced therapsids could have had a
combination of naked skin, whiskers, and scutes. A full pelage likely
did not evolve until the therapsid-mammal transition. The more
advanced, smaller therapsids could have had a combination of hair and
scutes, a combination still found in some modern mammals, such as
rodents and the opossum.
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The general hairlessness of humans in comparison to related species
may be due to loss of functionality in the pseudogene KRTHAP1 (which
helps produce keratin) in the human lineage about 240,000 years
ago. On an individual basis, mutations in the gene HR can lead to
complete hair loss, though this is not typical in humans. Humans
may also lose their hair as a result of hormonal imbalance due to
drugs or pregnancy.
In order to comprehend why humans are essentially hairless, it is
essential to understand that mammalian body hair is not merely an
aesthetic characteristic; it protects the skin from wounds, bites,
heat, cold, and UV radiation. Additionally, it can be used as a
communication tool and as a camouflage. To this end, it can be
concluded that benefits stemming from the loss of human body hair must
be great enough to outweigh the loss of these protective functions by
Humans are the only primate species that have undergone significant
hair loss and of the approximately 5000 extant species of mammal, only
a handful are effectively hairless. This list includes elephants,
rhinoceroses, hippopotamuses, walruses, some species of pigs, whales
and other cetaceans, and naked mole rats. Most mammals have light
skin that is covered by fur, and biologists believe that early human
ancestors started out this way also. Dark skin probably evolved after
humans lost their body fur, because the naked skin was vulnerable to
UV radiation as explained in the Out of Africa hypothesis.
Therefore, evidence of the time when human skin darkened has been used
to date the loss of human body hair, assuming that the dark skin was
needed after the fur was gone. It was expected that dating the split
of the ancestral human louse into two species, the head louse and the
pubic louse, would date the loss of body hair in human ancestors.
However, it turned out that the human pubic louse does not descend
from the ancestral human louse, but from the gorilla louse, diverging
3.3 million years ago. This suggests that humans had lost body hair
(but retained head hair) and developed thick pubic hair prior to this
date, were living in or close to the forest where gorillas lived, and
acquired pubic lice from butchering gorillas or sleeping in their
nests. The evolution of the body louse from the head louse, on
the other hand, places the date of clothing much later, some 100,000
The soft, fine hair found on many nonhuman mammals is typically called
The sweat glands in humans could have evolved to spread from the hands
and feet as the body hair changed, or the hair change could have
occurred to facilitate sweating. Horses and humans are two of the few
animals capable of sweating on most of their body, yet horses are
larger and still have fully developed fur. In humans, the skin hairs
lie flat in hot conditions, as the arrector pili muscles relax,
preventing heat from being trapped by a layer of still air between the
hairs, and increasing heat loss by convection.
Another hypothesis for the thick body hair on humans proposes that
Fisherian runaway sexual selection played a role (as well as in the
selection of long head hair), (see types of hair and vellus hair), as
well as a much larger role of testosterone in men.
Sexual selection is
the only theory thus far that explains the sexual dimorphism seen in
the hair patterns of men and women. On average, men have more body
hair than women. Males have more terminal hair, especially on the
face, chest, abdomen, and back, and females have more vellus hair,
which is less visible. The halting of hair development at a juvenile
stage, vellus hair, would also be consistent with the neoteny evident
in humans, especially in females, and thus they could have occurred at
the same time. This theory, however, has significant holdings in
today's cultural norms. There is no evidence that sexual selection
would proceed to such a drastic extent over a million years ago when a
full, lush coat of hair would most likely indicate health and would
therefore be more likely to be selected for, not against, and not all
human populations today have sexual dimorphism in body hair.
A further hypothesis is that human hair was reduced in response to
ectoparasites. The "ectoparasite" explanation of modern human
nakedness is based on the principle that a hairless primate would
harbor fewer parasites. When our ancestors adopted group-dwelling
social arrangements roughly 1.8 mya, ectoparasite loads increased
dramatically. Early humans became the only one of the 193 primate
species to have fleas, which can be attributed to the close living
arrangements of large groups of individuals. While primate species
have communal sleeping arrangements, these groups are always on the
move and thus are less likely to harbor ectoparasites. Because of
this, selection pressure for early humans would favor decreasing body
hair because those with thick coats would have more
lethal-disease-carrying ectoparasites and would thereby have lower
Another view is proposed by James Giles, who attempts to explain
hairlessness as evolved from the relationship between mother and
child, and as a consequence of bipedalism. Giles also connects
romantic love to hairlessness.
Another hypothesis is that humans' use of fire caused or initiated the
reduction in human hair.
Evolutionary biologists suggest that the genus
Homo arose in East
Africa approximately 2.5 million years ago. They devised new
hunting techniques. The higher protein diet led to the evolution
of larger body and brain sizes. Jablonski postulates that
increasing body size, in conjunction with intensified hunting during
the day at the equator, gave rise to a greater need to rapidly expel
heat. As a result, humans evolved the ability to sweat: a process
which was facilitated by the loss of body hair. A major problem
with this theory, however, is that it does not
explain why males are larger, hairier, and were more active in hunting
than females. The female-male size differential among other closely
associated primates is much greater than among humans, and therefore
it was reduced during human evolution. Other primates have sweat gland
in their armpits that function as those of humans, and thus it is
probable that human sweat glands evolved from a similar distribution,
spreading to more areas of the body, rather than occurring through
evolution of a new trait. It is not known whether the increased
distribution of sweat glands occurred before, during, or after, the
change in body hair, or even whether the two are related developments.
Horses also sweat, and they are larger, hairier, and expend more
energy running than human males, so there may not be any connection
between the ability to sweat and the apparent hairlessness of humans.
Another factor in human evolution that also occurred in the
prehistoric past was a preferential selection for neoteny,
particularly in females. The idea that adult humans exhibit certain
neotenous (juvenile) features, not evinced in the great apes, is about
a century old.
Louis Bolk made a long list of such traits, and
Stephen Jay Gould
Stephen Jay Gould published a short list in Ontogeny and
Phylogeny. In addition, paedomorphic characteristics in women are
often acknowledged as desirable by men in developed countries. For
instance, vellus hair is a juvenile characteristic. However, while men
develop longer, coarser, thicker, and darker terminal hair through
sexual differentiation, women do not, leaving their vellus hair
Human evolutionary genetics
Yellow curly hair and scalp from body which had long black wig over
hair. Parts of wig plait remains. From Egypt, Gurob, probably tomb 23.
18th–19th Dynasty. The Petrie Museum of Egyptian Archaeology, London
Man with curly hair (David Luiz)
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Jablonski asserts head hair was evolutionarily advantageous for
pre-humans to retain because it protected the scalp as they walked
upright in the intense African (equatorial) UV light. While some might
argue that, by this logic, humans should also express hairy shoulders
because these body parts would putatively be exposed to similar
conditions, the protection of the head, the seat of the brain that
enabled humanity to become one of the most successful species on the
planet (and which also is very vulnerable at birth) was arguably a
more urgent issue (axillary hair in the underarms and groin were also
retained as signs of sexual maturity). Sometime during the gradual
process by which
Homo erectus began a transition from furry skin to
the naked skin expressed by
Homo sapiens, hair texture putatively
gradually changed from straight hair (the condition
of most mammals, including humanity's closest cousins—chimpanzees)
Afro-textured hair or 'kinky' (i.e. tightly coiled). This argument
assumes that curly hair better impedes the passage of
UV light into
the body relative to straight hair (thus curly or coiled hair would be
particularly advantageous for light-skinned hominids living at the
It is substantiated by Iyengar's (1998) findings that
UV light can
enter into straight human hair roots (and thus into the body through
the skin) via the hair shaft. Specifically, the results of that study
suggest that this phenomenon resembles the passage of light through
fiber optic tubes (which do not function as effectively when kinked or
sharply curved or coiled). In this sense, when hominids (i.e. Homo
Erectus) were gradually losing their straight body hair and thereby
exposing the initially pale skin underneath their fur to the sun,
straight hair would have been an adaptive liability. By inverse logic,
later, as humans traveled farther from Africa and/or the equator,
straight hair may have (initially) evolved to aid the entry of UV
light into the body during the transition from dark, UV-protected skin
to paler skin.
Some[who?] conversely believe that tightly coiled hair that grows into
a typical Afro-like formation would have greatly reduced the ability
of the head and brain to cool because although African people's hair
is much less dense than its European counterpart's, in the intense sun
the effective 'woolly hat' that such hair produced would have been a
disadvantage. However, such anthropologists as Nina Jablonski
oppositely argue about this hair texture. Specifically, Jablonski's
assertions suggest that the adjective "woolly" in reference to
Afro-hair is a misnomer in connoting the high heat insulation
derivable from the true wool of sheep. Instead, the relatively sparse
density of Afro-hair, combined with its springy coils actually results
in an airy, almost sponge-like structure that in turn, Jablonski
argues, more likely facilitates an increase in the circulation of
cool air onto the scalp. Further, wet Afro-hair does not stick to the
neck and scalp unless totally drenched and instead tends to retain its
basic springy puffiness because it less easily responds to moisture
and sweat than straight hair does. In this sense, the trait may
enhance comfort levels in intense equatorial climates more than
straight hair (which, on the other hand, tends to naturally fall over
the ears and neck to a degree that provides slightly enhanced comfort
levels in cold climates relative to tightly coiled hair).
Further, some[who?] interpret the ideas of
Charles Darwin as
suggesting that some traits, such as hair texture, were so arbitrary
to human survival that the role natural selection played was trivial.
Hence, they argue in favor of his suggestion that sexual selection may
be responsible for such traits. However, inclinations towards deeming
hair texture "adaptively trivial" may root in certain cultural value
judgments more than objective logic. In this sense the possibility
that hair texture may have played an adaptively significant role
cannot be completely eliminated from consideration. In fact, while the
sexual selection hypothesis cannot be ruled out, the asymmetrical
distribution of this trait vouches for environmental influence.
Specifically, if hair texture were simply the result of adaptively
arbitrary human aesthetic preferences, one would expect that the
global distribution of the various hair textures would be fairly
random. Instead, the distribution of Afro-hair is strongly skewed
toward the equator.
Further, it is notable that the most pervasive expression of this hair
texture can be found in sub-Saharan Africa; a region of the world that
abundant genetic and paleo-anthropological evidence suggests, was the
relatively recent (~200,000-year-old) point of origin for modern
humanity. In fact, although genetic findings (Tishkoff, 2009) suggest
that sub-Saharan Africans are the most genetically diverse continental
group on Earth,
Afro-textured hair approaches ubiquity in this region.
This points to a strong, long-term selective pressure that, in stark
contrast to most other regions of the genomes of sub-Saharan groups,
left little room for genetic variation at the determining loci. Such a
pattern, again, does not seem to support human sexual aesthetics as
being the sole or primary cause of this distribution.
Straight black hair
The EDAR locus
A group of studies have recently shown that genetic patterns at the
EDAR locus, a region of the modern human genome that contributes to
hair texture variation among most individuals of East Asian descent,
support the hypothesis that (East Asian) straight hair likely
developed in this branch of the modern human lineage subsequent to the
original expression of tightly coiled natural afro-hair.
Specifically, the relevant findings indicate that the EDAR mutation
coding for the predominant East Asian 'coarse' or thick, straight hair
texture arose within the past ~65,000 years, which is a time frame
that covers from the earliest of the 'Out of Africa' migrations up to
Ringworm is a fungal disease that targets hairy skin.
Premature greying of hair is another condition that results in greying
before the age of 20 years in Whites, before 25 years in Asians, and
before 30 years in Africans.
Hair care involves the hygiene and cosmetology of hair including hair
on the scalp, facial, pubic and other body hair.
Hair care routines
differ according to an individual's culture and the physical
characteristics of one's hair.
Hair may be colored, trimmed, shaved,
plucked, or otherwise removed with treatments such as waxing,
sugaring, and threading.
Depilation is the removal of hair from the surface of the skin. This
can be achieved through methods such as shaving.
Epilation is the
removal of the entire hair strand, including the part of the hair that
has not yet left the follicle. A popular way to epilate hair is
Many razors have multiple blades purportedly to ensure a close shave.
While shaving initially will leave skin feeling smooth and hair free,
new hair growth can appear a few hours after hair removal.
Shaving is accomplished with bladed instruments, such as razors. The
blade is brought close to the skin and stroked over the hair in the
desired area to cut the terminal hairs and leave the skin feeling
smooth. Depending upon the rate of growth, one can begin to feel the
hair growing back within hours of shaving. This is especially evident
in men who develop a five o'clock shadow after having shaved their
faces. This new growth is called stubble. Stubble typically appears to
grow back thicker because the shaved hairs are blunted instead of
tapered off at the end, although the hair never actually grows back
Waxing involves using a sticky wax and strip of paper or cloth to pull
hair from the root.
Waxing is the ideal hair removal technique to keep
an area hair-free for long periods of time. It can take three to six
weeks for waxed hair to begin to resurface again.
Hair in areas that
have previously been waxed also is known to grow back finer and
thinner, especially compared to hair that has been shaved with a
Laser hair removal
Laser hair removal
Laser hair removal is a cosmetic method where a small laser beam
pulses selective heat on dark target matter in the area that causes
hair growth without harming the skin tissue. This process is repeated
several times over the course of many months to a couple of years with
hair regrowing less frequently until it finally stops; this is used as
a more permanent solution to waxing or shaving.
Laser removal is
practiced in many clinics along with many at-home products.
Cutting and trimming
See also: Ponytail
Because the hair on the head is normally longer than other types of
body hair, it is cut with scissors or clippers. People with longer
hair will most often use scissors to cut their hair, whereas shorter
hair is maintained using a trimmer. Depending on the desired length
and overall health of the hair, periods without cutting or trimming
the hair can vary.
Cut hair may be used in wigs. Global imports of hair in 2010 was worth
$US 1.24 billion.
See also: Hairstyle
Portrait of a Woman, Alessandro Allori (1535–1607; Uffizi Gallery):
a plucked hairline gives a fashionably "noble brow"
Hair has great social significance for human beings.  It can
grow on most external areas of the human body, except on the palms of
the hands and the soles of the feet (among other areas).
Hair is most
noticeable on most people in a small number of areas, which are also
the ones that are most commonly trimmed, plucked, or shaved. These
include the face, ears, head, eyebrows, legs, and armpits, as well as
the pubic region. The highly visible differences between male and
female body and facial hair are a notable secondary sex
The world's longest documented hair belongs to Xie Qiuping (China), at
5.627 m (18 ft 5.54 in) when measured on 8 May 2004. She has been
growing her hair since 1973, from the age of 13.
Indication of status
Healthy hair indicates health and youth (important in evolutionary
Hair color and texture can be a sign of ethnic ancestry.
Facial hair is a sign of puberty in men. White hair is a sign of age
or genetics, which may be concealed with hair dye (not easily for
some), although many prefer to assume it (especially if it is a
poliosis characteristic of the person since childhood). Male pattern
baldness is a sign of age, which may be concealed with a toupee, hats,
or religious and cultural adornments. Although drugs and medical
procedures exist for the treatment of baldness, many balding men
simply shave their heads. In early modern China, the queue was a male
hairstyle worn by the Manchus from central Manchuria and the Han
Chinese during the Qing dynasty; hair on the front of the head was
shaved off above the temples every ten days, mimicking male-pattern
baldness, and the rest of the hair braided into a long pigtail.
Hairstyle may be an indicator of group membership. During the English
Civil War, the followers of
Oliver Cromwell decided to crop their hair
close to their head, as an act of defiance to the curls and ringlets
of the king's men. This led to the Parliamentary faction being
nicknamed Roundheads. Recent isotopic analysis of hair is helping to
shed further light on sociocultural interaction, giving information on
food procurement and consumption in the 19th century . Having
bobbed hair was popular among the flappers in the 1920s as a sign of
rebellion against traditional roles for women. Female art students
known as the "cropheads" also adopted the style, notably at the Slade
School in London, England. Regional variations in hirsutism cause
practices regarding hair on the arms and legs to differ. Some
religious groups may follow certain rules regarding hair as part of
religious observance. The rules often differ for men and women.
Many subcultures have hairstyles which may indicate an unofficial
membership. Many hippies, metalheads and Indian sadhus have long hair,
as well many older indie kids. Many punks wear a hairstyle known as a
mohawk or other spiked and dyed hairstyles; skinheads have
short-cropped or completely shaved heads. Long stylized bangs were
very common for emos, scene kids and younger indie kids in the 2000s
and early 2010s, among people of both genders.
Heads were shaved in concentration camps, and head-shaving has been
used as punishment, especially for women with long hair. The shaven
head is common in military haircuts, while Western monks are known for
the tonsure. By contrast, among some Indian holy men, the hair is worn
extremely long.
In the time of Confucius (5th century BCE), the Chinese grew out their
hair and often tied it, as a symbol of filial piety.
Regular hairdressing in some cultures is considered a sign of wealth
or status. The dreadlocks of the
Rastafari movement were despised
early in the movement's history. In some cultures, having one's hair
cut can symbolize a liberation from one's past, usually after a trying
time in one's life. Cutting the hair also may be a sign of mourning.
Tightly coiled hair in its natural state may be worn in an Afro. This
hairstyle was once worn among African Americans as a symbol of racial
pride. Given that the coiled texture is the natural state of some
African Americans' hair, or perceived as being more "African", this
simple style is now often seen as a sign of self-acceptance and an
affirmation that the beauty norms of the (eurocentric) dominant
culture are not absolute. It is important to note that African
Americans as a whole have a variety of hair textures, as they are not
an ethnically homogeneous group, but an ad-hoc of different racial
Easy Rider (1969) includes the assumption that the two main
characters could have their long hairs forcibly shaved with a rusty
razor when jailed, symbolizing the intolerance of some conservative
groups toward members of the counterculture. At the conclusion of the
Oz obscenity trials in the UK in 1971, the defendants had their heads
shaved by the police, causing public outcry. During the appeal trial,
they appeared in the dock wearing wigs. A case where a 14-year-old
student was expelled from school in
Brazil in the mid-2000s, allegedly
because of his fauxhawk haircut, sparked national debate and legal
action resulting in compensation.
Women's hair may be hidden using headscarves, a common part of the
Islam and a symbol of modesty required for certain religious
rituals in Eastern Orthodoxy.
Russian Orthodox Church
Russian Orthodox Church requires all
married women to wear headscarves inside the church; this tradition is
often extended to all women, regardless of marital status. Orthodox
Judaism also commands the use of scarves and other head coverings for
married women for modesty reasons. Certain
Hindu sects also wear head
scarves for religious reasons. Sikhs have an obligation not to cut
hair (a Sikh cutting hair becomes 'apostate' which means fallen from
religion) and men keep it tied in a bun on the head, which is then
covered appropriately using a turban. Multiple religions, both ancient
and contemporary, require or advise one to allow their hair to become
dreadlocks, though people also wear them for fashion. For men, Islam,
Orthodox Judaism, Orthodox Christianity, Roman Catholicism, and other
religious groups have at various times recommended or required the
covering of the head and sections of the hair of men, and some have
dictates relating to the cutting of men's facial and head hair. Some
Christian sects throughout history and up to modern times have also
religiously proscribed the cutting of women's hair. For some Sunni
madhabs, the donning of a
Topi (cap) is a form of sunnah.
Chaetophobia – the fear of hair
Hair analysis (alternative medicine)
Hypertrichosis – the state of having an excess of hair on the head
Hypotrichosis – the state of having a less than normal amount of
hair on the head or body
Seta – hair-like structures in insects
Trichotillomania – hair pulling
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Wikimedia Commons has media related to Hair.
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List of hairstyles / facial hairstyles
Human hair color
Brown (varieties: Chestnut • Auburn)
Red (varieties: Auburn • Titian)
Hair dye stripping
Disappearing blonde gene
Melanocortin 1 receptor
Braid or Plait
High and tight
Historical Christian hairstyles
Regular taper cut
Shag (Shaggy hair)
Short back and sides
Short brush cut
Shenandoah (Chin curtain)
Male-pattern hair loss
Curly Girl Method
Shampoo and set
My Nappy Roots: A Journey Through Black Hair-itage (2008)
Good Hair (2009)
Afro-textured hair (Kinky hair)
Good hair (phrase)
Hair fetishism (pubic)
Skin and related structures
Loose connective tissue
Sweat glands: Apocrine sweat gland
Eccrine sweat gland
Outer root sheath
Inner root sheath
Bulb with matrix cells
Arrector pili muscle
Hair sebaceous gland
Last common ancestors
H. e. erectus
H. e. georgicus
H. e. lantianensis
H. e. nankinensis
H. e. palaeojavanicus
H. e. pekinensis
H. e. soloensis
H. e. tautavelensis
H. e. yuanmouensis
H. s. idaltu
H. s. sapiens (anatomically modern human)
Red Deer Cave people
Origin of modern humans
Recent African origin
Evolutionary biology portal
BNF: cb119311767 (data)