Pubic hair is hair in the frontal genital area, the crotch, and sometimes at the top of the inside of the legs; these areas form the pubic region. Although fine vellus hair is present in the area in childhood, the term pubic hair is generally restricted to the heavier, longer hair that develops with puberty as an effect of rising levels of androgens on the skin of the genital area. Pubic hair is therefore part of the androgenic hair.
Development of pubic hair
Before puberty, the genital area of both boys and girls has very fine vellus hair, referred to as Tanner stage 1 hair. In response to rising levels of androgens as puberty begins, the skin of the genital area begins to produce thicker, often curlier, hair with a faster growth rate. The onset of pubic hair development is termed pubarche. The change for each hair follicle is relatively abrupt, but the extent of skin which grows androgenic hair gradually increases over several years.
In most girls, pubic hair first appears along the edges of the labia majora (stage 2), and spreads forward to the mons (stage 3) over the next 2 years. By 3 years into puberty (roughly the time of menarche for most girls), the pubic triangle is densely filled. Within another 2 years pubic hair also grows from the near thighs in most young women, and sometimes a small amount up the line of the abdomen toward the umbilicus.
In boys, the first pubic hair appears as a few sparse hairs on the scrotum or at the upper base of the penis (stage 2). Within a year, hairs around the base of the penis are too numerous to count (stage 3), and within 3 to 4 years, hair fills the pubic area (stage 4), and by 5 years extends to the near thighs and upwards on the abdomen toward the umbilicus (stage 5).
Other areas of the skin are similarly, though slightly less, sensitive to androgens and androgenic hair typically appears somewhat later. In rough sequence of sensitivity to androgens and appearance of androgenic hair, are the armpits (axillae), perianal area, upper lip, preauricular areas (sideburns), periareolar areas (nipples), middle of the chest, neck under the chin, remainder of chest and beard area, limbs and shoulders, back, and buttocks.
Although generally considered part of the process of puberty, pubarche is distinct and independent of the process of maturation of the gonads that leads to sexual maturation and fertility. Pubic hair can develop from adrenal androgens alone, and can develop even when the ovaries or testes are defective and nonfunctional. See puberty for details.
There is little if any difference in the capacity of male and female bodies to grow hair in response to androgens. The obvious sex-dimorphic difference in hair distribution in men and women is primarily a result of differences in the levels of androgen reached as maturity occurs. Patterns of pubic hair vary among people. On some people, pubic hair is thick and/or coarse, while on others it may be sparse and/or fine.
Pubic hair and axillary (armpit) hair can vary in color considerably from the hair of the scalp. In most people it is darker, although it can also be lighter. On many men, pubic hair color is closest to the color of their beards (before their beards start turning white with age), which again can vary from the color of the hair on top of the head. On most women, the pubic patch is triangular and lies over the mons veneris, or mound of Venus. On many men, the pubic patch tapers upwards to a line of hair pointing towards the navel (see abdominal hair). As with axillary (armpit) hair, pubic hair is associated with a concentration of sebaceous glands in the area.
Reason for pubic hair
It is believed that the functions of pubic hair include the dissemination of pheromones and protection from the friction of sexual intercourse. Natural selection may also have sustained it because it can show a potential sexual partner that the other person is sexually mature and can reproduce. Pubic hair and the growth between the tops of the legs and the buttocks, like under arm hair, helps to lubricate the areas, making movement smoother and more comfortable.
There is no definitive theory on the reason for the existence of pubic hair. The prevailing theory relates to pheromones — scents that the body produces that can be sexually stimulating to others. In this theory, the tufts of hair that grow around the genitals, as well as under the arms, capture these erotic scents. Pheromones get trapped in the pubic hair when apocrine glands release an odorless secretion on the surface of the skin that combines with bacteria decomposed by the secretions of the sebaceous glands. Humans have the same number of hair follicles as gorillas, chimpanzees and orangutans, but body hair is generally very fine or barely visible in comparison. So, while pubic hair and underarm hair might be considered the primary scent traps, they are not the only ones. For some people, scents from these areas are noticeable and consciously increase sexual arousal. Pheromones might not be obvious but may be detected subconsciously.
Another theory is that the pubic hair keeps the genitals warm. The purpose of women's pubic hair could be similar to that of the cilia in the nose, in that it prevents small foreign particles from entering the vagina. However, this doesn't explain male pubic hair.
Attitudes toward pubic hair are similar to those regarding axillary armpit hair in that cultural and personal norms can be reflected in reactions ranging from pleasure to revulsion, both for the presence and absence of such hair. As with any sexually charged matter there are persons of both sexes who have strong points of view toward the culturally related issues associated with presence or lack of body hair.
Some common slang includes bush, muff, curlies, pubes, fuzz.
Modification and removal of pubic hair
Some arguments for modification of pubic hair have included:
In Islamic societies, removing the pubic hair is a religiously endorsed practice.
Trimming or completely removing pubic hair has become a custom in many cultures. A preference for hairless genitals is known as acomoclitism. The methodology of removing hair is called depilation (when removing only the hair above the skin) or epilation (when removing the entire hair). The trimming or removal of body hair by men is sometimes referred to as manscaping.
The modification of pubic hair can also be considered a statement about one's style or personal lifestyle as can leaving it unmodified. Some styles include :
- Natural — no trimming or maintenance
- Trimmed — hair length is shortened but not removed or shaped
- Triangle — hair removed (generally waxed) from the sides to form a triangle so that pubic hair cannot be seen while wearing swimwear
- "Landing strip" — hair removed except a small, centered, vertical line
- Bare — pubic hair completely removed
- Dyed — colouring hair to match hair on the head, or to give it a unique look (for example, red--in the shape of a heart)
- Others — V-shaped, heart-shaped, arrow, initials, etc.
- Pubic Hair Distribution Study categorizes four types of pubic hair patterns and summarizes observed occurrence of each type of pattern.