Men adopt short haircuts, with women often letting their hair grow longer. Simple fashion or biological phenomenon?
Chinese Xie Qiuping has the longest hair in the world, at 5.62 meters. No official record for men, but it appears that Vietnamese Tran Van Hay, who died in 2010 at the age of 79, had a mane of 6.70 meters long, or 1.08 meters longer. However, if a man and a woman grow their hair together, the woman’s hair should end up being longer.
Indeed, even if the hair grows at the same speed in both sexes (about 1.25 cm per month), the anagen phase (when the hair grows) is generally longer in women. In women, it lasts about six years, compared to only three years in men. This difference would be due to estrogen, female hormones.
Conversely, testosterone produced by men accelerates the hair cycle. There are, however, strong differences between individuals and hair type. In Asians, the anagen phase can last up to 7 years while it is shorter in people with frizzy hair.
Long hair, an asset for seduction?
Why has evolution favored hair growth in women? Mystery. This sexual dimorphism could be a simple asset of seduction, like the colorful plumage of male birds. A study published in 2004 indicates that men perceive women with long hair as healthier.
However, another 2008 study did not find any difference in attractiveness in women with short or long hair. These observations have in any case a cultural dimension much more than natural.
If men have shorter hair, they are able to compete with other assets: the Canadian Hans N Langseth, who died in 1927, thus sported a beard of 5.33 meters.