This information about hair has been hidden from the public since the Viet Nam War...

...Hair is an extension of the nervous system, it can be correctly seen as exteriorized nerves, a type of highly evolved 'feelers' or 'antennae' that transmit vast amounts of important information to the brain stem, the limbic system, and the neocortex.

Not only does hair in people, including facial hair in men, provide an information highway reaching the brain, hair also emits energy, the electromagnetic energy emitted by the brain into the outer environment. This has been seen in Kirlian photography when a person is photographed with long hair and then rephotographed after the hair is cut.