Social role of hair

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 (Mou, 2008; Fujimoto, 2008; Fujimoto, 2008b). 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. This indicates that the initial expression of this trait among modern humans occurred only after the migration of humans out of sub-Saharan Africa.

Hair has great social significance for human beings. It can grow on most areas of the human body, except on the palms of the hands and the soles of the feet (among other areas), but hair is most noticeable in 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, nose, ears, head, eyebrows, eyelashes, 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 characteristic.Portrait of a Woman, Alessandro Allori (1535 - 1607; Uffizi Gallery): a plucked hairline gives a fashionably "noble brow"

Healthy hair indicates health and youth (important in evolutionary biology). Hair colour 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, which can be concealed with hair dye. A well known old wives' tale often told to children claims that eating a large portion of bread crusts can make hair curly. Male pattern baldness is sign of age, which can be concealed with a toupee, hats or religious/cultural adornments. In modern times, it can be reversed in some men with minoxidil (marketed as Rogaine or Regaine) or finasteride (marketed as Propecia); see Baldness treatments. Rather than these options, many men simply shave their heads for a clean look. Males in some religious groups, for example Sikhs and Orthodox Jews, may follow certain rules regarding hair as part of their faith, e.g. never cut their hair, or shave some or all of it. Some groups, such as women in the Muslim and orthodox Jewish communities, cover their hair as part of religious observance. Hair whorls have been discovered to be associated with brain development.