Why does head hair grow indefinitely but other body hair doesn’t?
Cecil does a little smoke and mirrors routine in this column I think. Sure, he corrected the ‘scalp hair grows indefinitely’ misstatement, but dodges the main question of why scalp hair grows so much longer.
Dig deeper Unca Cecil, what’s the evolutionary advantage?
Good question. No one knows the answer. Next question?
We can make assumptions. For example, does having a full head of hair allow you to live better than some baldy. The answer is yes. You attract more babes than old chrome dome does.
Okay, maybe that’s not the answer. We could determine that having a full head of hair helped cool the old noggin in the hot African sun, but you’d think just a bit of hair would be enough. Why so long? Long hair gets dirty, is hard to maintain, and attracts all sorts of parasites. You know baldy doesn’t have hair lice. That puts us back to* the babes* hypothesis.
Darwin had two theories: One, is natural selection aka “The Survival of the Fittest”. The other isn’t as well known, and is called Sexual Selection.
Darwin wondered if natural selection is the only way traits are passed down, why do we see such ill adaptive traits as the peacock’s tail. Certainly, short tailed peacocks could escape from predators faster and take less energy moving around, so peacock tails, natural selection wise, should be small and short. Darwin’s solution to the problem was sexual selection.
According to Sexual Selection, animals must select a mate that is the strongest and fittest. This could be the biggest creature, or the one who’s the fastest. Maybe the one with the shiniest fur or the bushiest tail. The selection must be done with a sign that can’t be cheated upon. That is, animals that aren’t fit can easily display the sign.
Let’s take the whatits, an imaginary creature. The female whatsit needs to find a fit male whatsit and decides that a small crooked tail would be a great sign of whatsit fitness. Unfortunately, nonfit whatsits can also grow small crooked tails, so there’s no way for a female whatsit to know who’s a fit mate and who isn’t.
Instead, the female whatsit might decide that a big, bushy tail is a good sign for fitness. The bigger and bushier the tail a male whatsit has, the more fit that creature must be. Weak whatsits can’t grow a big bushy tail. It takes a lot of nutrition to grow one, and you can’t be overrun by parasites or sick. Big bushy tails also are heavy and slow you down, so male whatsits with big bushy tails must be able to be strong enough and fast enough to fight off or out run predators. Thus, a big bushy tail is a good sign for physical fitness.
Now, it’s not that the female whatsit decided one day that big bushy tails are sexy. Again, natural selection takes part. Female whatsits who likes small crooked tails selected unfit mates and their lineage died off. Female whatsits who selected mates with big bushy tails selected the fittest mates, and thus their lineage continued.
Your head of hair may simply be a way of signaling your fitness. You can’t fake a big think head of hair, and it takes a lot of good nutrition, time, and health to maintain it too. You know what your hair looks like when you have the flu. Like the whatsit’s tail, we evolved to have longer and more hair because it became a sign of individual fitness.
As a baldy, let me say that everyone with hair lives better than I do because they’re not so damn cold!
It could also simply be a genetic consequence of long female hair. A male taste for long female hair seems to be all but universal among the non-kinky-haired races (on the rare occasions that short female hair is fashionable, it seems to go with a wholesale “boyish” look, as in the 1920s, with no hips or breasts to speak of, either).
Both sexes are attracted to a think healthy head of hair. Ask any man without it.
Me I’ve got plenty of hair. Now if I could just get to migrate off my back and onto my head…
I always thought that it was related to how primates carry their young and the fact that we have little to no body hair.
Primates get around with small young by having the young grip the mother’s fur with hands (and usually feet) leaving the mother free to use both hands.
Human babies can’t do this since we don’t have enough body hair, but they are capable of supporting most if not all of their weight with their grip soon after birth, and will reflexivly do so.
I assume that a long mane of hair would give a baby something to hold onto if the mother needed both hands.
Couldn’t get my long-haired friend to test this out with her fist baby, maybe the next…LOL
Well if the child’s palmar grasp reflex was activated by a mother’s hair, then there’d be good reason to be more attracted to women with long hair. I suppose the “unpredictable” part is a little worrying, but perhaps now that mothers use pushchairs babies without the predictable palmar grasp’s can spread their genes…
Course, there’s still the fetishisation of the different. I know plenty of guys that were strangely aroused by Natalie Portman’s dome.
Tell the women who find Picard sexier than Kirk that bald is a negative sexual selection trait.
Powers &8^]
I think the original evolutionary mechanism had more to do with spreading scent. Humans secrete pheromones at the back of the neck and hair helps spread them on the wind.
Also, the smell of a baby’s head is one of the primary bonding points of motherhood. Most Mothers will admit in private that they sneak a smell of their chidren’s heads well into elementary school ages.
Cite?
This seems wildly speculative. First, having an infant dangle from your hair does not sound in any way comfortable. Getting your hair pulled is a painful experience. Second, human infants are much less developed than many other mammals when born. They are unable to support their own heads. Having said infant dangle from your body without other support does not seem plausible.
Actually, this is probably it. Certainly a man with a full head of hair looks younger than a man with a bald spot (and thus, probably healthier). While bald men can be considererd attractive, it seems that it’s more the men who’ve shaved their heads completely that seem to be considered attractive then men who are balding. Certainly in my own life, when I shaved my head completely, I was told I looked a lot better than when I just had a bald spot. Also, I was told that by shaving my head completely, I looked younger than when I was just balding (though, obviously, I was still the same age).
As for females, like John W. Kennedy says, it does seem to be that men are nearly universally attracted to women with long hair (though I’ve seen it among kinky haired women, as well, which may be more of a cultural thing among Americans/Caucasians than it is in Africa).
Marc