Asked by: Jenny Lund, Preston

Advertisement

Hair growth in humans is complicated and influenced by several different genes and hormones. The prevailing theory is that we evolved to have less hair than primates because our ancestors evolved sweating as a strategy to keep cool on the African savannah, and too much hair gets in the way of sweating.

But the evolutionary reasons why hairiness varies with ethnicity are unclear. Caucasian people are generally hairier than the Japanese, for example, even though testosterone levels are the same. The difference seems to be in how sensitive the hair follicles are to those testosterone levels.

Read more:


Advertisement

Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.

Authors

luis villazon
Luis VillazonQ&A expert

Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.

Advertisement
Advertisement
Advertisement