What is the evolutionary significance of hair on your head?

Answer 1

Social Status. Hair has always been the symbolic evidence of your social status. OR if you are talking more scientific... It's because your head is the first "device" used by the body to cool itself off. This is evident when you sweat through your head before anywhere else in your body... (assuming you have no sweat issues with armpits and other areas due to diet, thyroid, etc.). Or like this: when it's cold outside, the first place that your body begins to lose heat is through the pores in your head. The hair is supposed to help your head retain the heat rather than it simply leave your body forever! That's why you should ALWAYS wear a hat in the winter time even if you have a whole head of hair... just to protect your body and keep it at a healthy temperature to fight of infections, viruses etc. Evolutionally... Hair is supposed to be long enough to function efficient enough for your body to retain heat.