Male-pattern baldness, genetics and evolution

It’s widely known that male-pattern baldness, or a loss of hair later in life has a genetic origin. Some argue that this is inherited from the mother, but more recently it is believed that either parent may be responsible. Leaving aside the chemical and hormonal interplay of DHT (dihydrotestosterone) and the actual mechanics of hair loss, I’d like to propose my own theory as to why men go bald.

Most genetic traits are there for a reason and as a species we have changed over millions of years to exploit certain physical and biological attributes that benefit us. Walking upright, a large brain, stereoscopic vision and an opposable thumb are just a few examples of this. So why not baldness? So many man become bald later in life that you could be forgiven for thinking we’re part of one big cosmic experiment. Maybe that’s another evolutionary experiment that is ongoing and we’ll see the results (or not) thousands of years from now.

There are already lots of discussions going on about evolutionary changes and the advantages that bald men in particular may have. For example it is believed that a bald man may signify social maturity and a less aggressive, more nurturing individual that females looking for a nurturing mate may be attracted to. A bald man indicating maturity and stature may well be successful and therefore a prize catch. There’s even theories about DHT hair loss and male labido. Most of this is all speculative and no one can really say for sure.

My theory about male-pattern baldness stems from the actual purpose of hair itself rather than and social implications. It came to me in the shower recently when I realised my hair felt a little greasy even though I had only washed it the day before. As you may know, hair has its own self-cleaning properties and people who wash their hair every day may notice that at the end of the day theirs may feel slightly greasy as the hair attempts to over-compensate and replenish the natural oils that have been stripped away by the washing process. Why does hair want to be oily? Presumably this has something to do with repelling dirt and water. You see everything our body does, it does for a reason.

Bald man eating ice cream We have hair on our bodies for a reason too and it’s mostly to do with temperature control. I’m sure the hairdressers out there might try to tell you different, but there it is. You may have noticed that we have slightly less body hair than our ape cousins though.

Since we learned to control fire and have taken wearing clothes and living in large centrally heated caves we need a little less of it than we used to.

Our noggin, however, is generally exposed and a bald man will tell you that when it’s cold and he doesn’t have his beanie on he really feels it. Hair can serve other purposes apart from temperature control (underarm hair for example).

Back to evolution again and one of the most significant changes to occur is the development of large brain. You have one of these, although you may know one or two individuals that weren’t on the list when these were allocated! This large brain has allowed our species to achieve many great things, in fact the device you are reading this page on right now is one of those ‘miracles’. A large brain does have very specific temperature requirements and our ability to sweat helps keep us cool. Incidentally, another possibility as to why we have less body hair is that it interferes with the cooling system. Sweating only dissipates heat with good air circulation and lots of body hair would prevent this. So there you have it, a sweaty forehead keeps you cool and a fluffy barnet helps keep the brain warm when it’s cold. A perfect combination you might say.

So why do men go bald? I believe that it could have something to do with changing temperature requirements. Our bodies change as we grow older and in general many of our functions become less efficient with age. Perhaps this is natures way of ensuring that the cooling system isn’t compromised, after all the large brain is one of our most important attributes and our very survival depends upon it. Perhaps in time the bald head will become a permanent fixture among the majority of men, just as relatively less body hair is a common trait now.

So why don’t women go bald too? Well that’s a bit of a mystery and I’m sure their brain size has nothing to do with it (I heard you snickering in the corner there!). Perhaps one explanation is the physiological differences between men and women. We belong to the same species but are different in many ways. Female-pattern baldness does exist, but it doesn’t follow the same profile as male-pattern baldness. As I said, there are differences and I don’t have a definitive temperature related explanation. One possibility is the historically differing roles that men and women have, hunting versus nurturing offspring etc., we can only speculate.

Disclaimer: The ideas in this article are theories only and not to be taken as fact as I am not an expert in any of the relevant fields of study. However, the day we stop thinking about things and coming up with ideas (no matter how crazy) will be the day our brains all start to shrink again!

Male-pattern baldness, genetics and evolution

Other articles in this category