Pubic hair; why?

[HydrogenBond]

Here is sort of a funny to talk about topic. What is the biological reason for pubic hair? This springy hair is only located in one spot on the body.

I always thought that maybe it had to do with scent since it does tend to get a little musty. But a female American Indian friend of mine said it was needed to lower friction during sex. If the pubic hair wasn't there the skin would get more irritated making the transfer of disease easier via the irritated skin. It sort of makes sense, since this springy hair is low friction even when wet. Are there any other reasons anyone can think of?

[InfiniteNow]

The two reasons you listed are generally recognized as the prevailing theories (as nobody knows "for sure"). One other reason sometimes discussed is so you can know if the object of your attraction has reached an age such that they can reproduce. Of course, most of evolution happened prior to clothing, and this theory is valid, but less relevant now.

[Racoon]

I think pubic hair is about heat loss.

[Mercedes Benzene]

I know that it certainly helps to prevent chafing when running.
Thank goodness for pubic hair.
Other than preventing friction, the only other reason I've heard is to trap pheromones and other natural human scents.

[Turtle]

It's for flossing the teeth after sex.

[Boerseun]

Interesting topic!

I have always thought that it is for increasing surface area from where pheromones can be better distributed. But here's the problem - with our heads changing the way they did to make the eyeballs move to the front for excellent binocular vision to ease our life in the trees, and our brains moving over forward to give the cerebral cortex some space, our nasal cavities have shrunk to such a degree that amongst animals, we're some of the worst olfactory-capable species. We can't smell to save our lives. So I don't think the pheromone thingy is the primary reason.

If we look at the chafing hypothesis, there might be something there. We have very much the same hair under our armpits, too - everywhere clothing can be constricted and cause chafing. But for this to be of evolutionary origin, individuals must have died because of chafing. You seldom hear of people chafed to death. I wonder...

We shouldn't ask why we have pubes or armpit-hair. The question should be "why don't we have the same hair everywhere else?" And it seems reasonable, because we do have hair everywhere else, though in a much atrophied form. Except hair on the head - but that is clearly for heat insulation; we lose more than 80% of our body heat through our heads. (I wonder if skinheads eat more than hairy folks, or are on average thinner?)

So why did the hair atrophy everywhere else? Basically, the same question - but from a different angle.

It could be because of sexual selection, where people started preferring less hairy partners. Had nothing to do with survival, it might even be detrimental because hair is an efficient heat-trapper and will make you loose less energy through thermal radiation. But sexual characteristics need not be beneficial in any form except for pleasing the opposite sex - look at a peacock, for example. And having been wearing the skins of other animals as clothes for quite a while, selection of this nature could have been done only on visible cues, and pubes were hidden under loincloths etc. I don't think this argument holds a lot of water, though.

I dunno. Bit it's interesting to speculate, though. I do think friction might be the answer, but I've never heard of anyone being chafed to death...

...unless the chafing went all septic and gross, and back in the cave-dwellin' days, you probably could die from infected chafing and no soap...
...or individuals with chafed naughty bits simply shagged less, because it was painful? Then they don't need to actually die from it?

[Drip Curl Magic]

I always thought it had something to do with keeping us warm. That area can be very sensitive to those sorts of things.

But then again, clothing takes care of that nowadays. Even after evolving out of most of the rest of the hair on our body, we still get decently thick pubic hair.

Is there any evidence that pubic hair is slowly becoming less and less thick as we evolve?

[Turtle]

OK...I fess up to just making up the dental floss thing and also planning to claim that Johnson of Johnson & Johnson made the first flat dento-tape based on a pube caught in his teeth in 1916.

Returning to the science of pubes, we have first the curliness which is due to a cross section that is flattened rather than round as is head hair. The purpose of pubic hair is to reduce skin to skin friction when having intercourse in the missionary position, something only humans can physically achieve. The reason pubes are curly is that if they were round in cross section like head hair, then the rubbing together of the hairs would twist them together like dread-locks. The truth, the whole truth, & nothing butt the truth.

[Jay-qu]

I agree with the chaffing, works for the underarms too. I have also thought that it was something to do with warmth, but really how much can that amount of hair do..

[maikeru]

Good lord, Turtle! Quite the punster you are! I agree with the chafing explanation. Now, another related question: chest hair, why?