Have you ever really thought about how strange it is to have hair? Or, why we have hair in certain places? It seems strangley odd to have hair springing from our pores. It raises so many questions. Why is it a certain color, thickness, length and oriented in a certain direction? Why do we have it at all? Why is it only present in certain places? We seem fairly naked as far as mammals go, but in fact only the palms of our hands and the bottoms of our feet are completely hairless. Everywhere else our bodies are populated with hair of different lengths and thickness. It’s something I’ve often thought about and been interested in, since on the surface it seems rather arbitrary.
- The Hair Helmet – Why do we have the most hair on top of our heads? Your scalp is covered with thousands of blood vessels in order to keep your brain’s temperature regulated. Hair does a great job of insulating your head and hair actually protects your head from scratches and injuries. You can scratch hair a lot harder than you can scratch bare skin. When you’re hot, your hair also helps prevent your sweat from evaporating too quickly or running into your eyes.
- Eyebrows and eyelashes – Eyebrows and eyelashes serve many different purposes. They can help regulate the amount of sunlight that enters your eyes through squinting. Your eyelashes will interlock and still allow you to see out, like natural sunglasses. Eyebrows and eyelashes also help prevent dust and germs from entering your eyes. And, eyebrows catch sweat that runs down from your head. Eyebrows also help communicate body language and expression. If you’ve ever gone to the zoo and seen the monkey exhibits, you will see how eyebrows are used to communicate body language. Some primates have lighter patches under their eyebrows that flash out when they raise their eyebrows in alarm. As social animals, primates make good use of facial expressions to communicate and eyebrows are an important part of this signaling.
- Sensitive areas – The hair under the arms and in genital areas serves several interesting functions. Much like blossoming flowers, sexually mature human beings release sweat in these areas that is thick with pheromones to entice members of the opposite sex. Under magnification this sweat is even cloudy in appearance. The hair traps this pheromone-rich sweat for use in signaling sexual fertility and health to nearby interested parties. Hair also protects the genitals from chafing and injury, as well as from dust and germs.
- Beards – Beards are harder to explain. Why do men have beards and women do not? What purpose do they serve? What does it mean that beards are out of fashion and have been for so long? According to one source, beards provide a good way to tell if someone is a mature male at a distance. This came in handy when we were running around sticking spears into each other. It was generally a bad idea to run into rival males from other tribes. That and maybe cave men and women looked pretty similar without beards. Beard hair also protects your face while running through the brush after prey. Although later in history, Alexander the Great made his men cut off their beards before battle since he thought it might be a disadvantage during close combat. This is part of the reason why the modern military style is for close-cropped hair and beard.