What is it with those bizarre hairs that sometimes seem to grow overnight on weird places of our body? They just appear as if they were fed Miracle-Gro. They're two or three times longer than other body hair. It's wacky.
-- Perplexed Paul, the net
Why, when a man gets older, does he lose hair from his head and gain it in his nose and ears?
-- Marie, the net
As people get older, their hormone balance changes. Women lose some female hormones and begin to grow hair in odd places. Men lose male hormones and lose muscle mass, aggressiveness, etc. Men move toward the feminine and women grow toward the masculine. So why do men grow more body hair and lose their head hair as they get older? Why don't we have smooth, soft skin and luxuriant tresses on our heads?
-- Hairy Harry in Bonita
Yeah, Harry, I know what you mean. Pa Alice's bra size is now bigger than Ma's. But that's more Krispy Kremes than hormones, I'm pretty sure. This hair freakout is something else, though. And I guess it would be cool if "male" and "female" hormones behaved as Harry imagines-- gradually Mom turns into Dad and Dad turns into Mom, and everybody ends up with a grandpa named Edna and a grandma named Chuck. As usual, life and hormones and follicles are much more complicated than that.
First of all, we never grow "new" hair. We're born with all the follicles we'll ever have. Some produce so-called vellus hair (soft, short, pale, hardly visible) and some produce terminal hair, the darker, more obvious stuff. We couldn't get staff quack Dr. Doctor to swear to this, since no research has definitely confirmed it, but the best guess at the moment is that as we age, certain follicles become more sensitive to testosterone and stop producing vellus hairs and start sprouting terminal hairs. In women this usually happens in the so-called "sexual" hair distribution areas (beard, moustache, abdomen, thighs); in men it's more often the ears and nose. Strangely, it's a form of testosterone, DHT, that causes hair loss.
As for "wild" hairs, they're more follicular delinquents than victims of hormone changes. Each of our 100,000 or so body hairs has at its base a bulb of cells that controls potential length, color, thickness, growth rate, and other qualities. As hairs grow, rest, and shed, the bulbs are replicated and keep things predictable. But each follicle acts more or less independently of the others, so there's always a potential for a screw-up of some sort. A wild hair grows from a follicle that has lost its original master plan, so the hair can bust out and follow its own demented path.
There are still plenty of hair questions to be answered, and since every new research finding produces a ton of fuzz-growing and fuzz-squelching products for the boomers, we certainly can expect our hairy body of knowledge to grow exponentially.