Both chimps and humans have the same number of hair follicles about 5 million. However, the human hair is thinner and more transparent than the hair of other primates.Hence, although we have equal number of hair, the chimps look hairier. We have lost our fur and no one knows why for sure, there are many theories
floating around (and you can cough out your own theory too, no one will mind). But I would like to agree to the one proposed by Darwin, 'Sexual Selection' . Darwin believed that as we humans evolved, our ancestors
chose partners with lesser and lesser hair and the hairy ones finally lost out. We see this even today, where our fascination for that smooth, hairless female skin makes the women spend painful hours waxing in a parlour. Similarly, we men have to spend time everyday in front of the mirror, to satisfy the women's need for clean shaven men. Now again no one knows why men retained facial hair, but for this I have my own theory
(all brickbats for me, not Darwin) I believe, our ancestral women were much more tolerant towards men with facial hair than men were towards women. May be after a day of hunting the woolly mammoth, men wanted to feel something much smoother! The present day women though have lost that tolerance and I am sent right back to the shaving mirror, even if a stub of hair protrudes from my face!