Potentially Inappropriate Posts Part 1: Human Sexuality, Part 1
Posted Mar 04 2009 3:13pm
I like dinosaurs, gaming, paleontology in general, movies, very few comics (mostly webcomics at this point), H. P. Lovecraft, and...wait for it... women. I know, I'm a bad person. But don't worry too much, it's not a "ooh, boobies!" kind of thing (although there's some of that, too). Modern man has some backwards sexual tendancies compared to most of the rest of the vertebrate community, especially other mammals or, heck, non-human primates.
And it's something that interests me. Time to be totally up-front here: I'm a breast man. Thus, the picture at left (Denise Milani). I also prefer an hourglass figure. I don't think these are bizarre human male tendances. They must mean something, right?
But why do I like breasts and an hourglass figure while my friend Luke likes legs and a tone midriff? Why does my friend Erik like butts and...a tone midriff? Why do both of them (and some of my other friends) prefer smaller breasts?
In a total reversal from most other vertebrate animals, it is the females of Homo sapiens sapiens that are the sexual "billboards" (in general). Big breasts, long legs, tone midriff (don't understand that one), bubble butt, these are all desirable traits. But in most non-human vertebrates, males compete for females by being billboards. Ceratopsians had giant frills and big horns. Male elephant seals are enormous, blubbery, and have trunks. Male baboons have bright faces and giant canines. Male birds of paradise are ridiculously colorful and have bizarre plumage that's useful only for attracting the opposite sex. But women have breasts, butts, and legs, which they show off with swimsuits, low-cut tops, and short skirts. Men can do the same thing, but the opposite effect is usually achieved: no woman I've ever met likes a guy with super-huge muscles, for example.
Another interesting reversal is the breasts themselves. In non-human primates, breasts are used primarily to nurse the young. Males are attracted to the females posterior when it becomes swollen during breeding season (that's estrus). Humans don't really go through a visible estrus cycle (although that's debatable), so the butt was replaced by larger breasts. But there's a tradeoff here--breasts don't just swell and shrink depending on the season. They stay large! So human females are essentially advertising their sexuality all the time, and clothing is used to openly advertise it or not. Men, however, do not have such obvious sexual organs. Facial hair may be the male "billboard," but it doesn't have the same draw as...well, Denise up there. In Homo sapiens sapiens, the females are primarily competing for male attention instead of the other way around.
You can see this yourself by going to a bar or pool hall on the weekend. Men dress casual, in T-shirts and jeans, but women use perfume and revealing clothing to attract attention to themselves. If men and women were peacocks, the sexes would be reversed! The females would have big showy feathers, and males would be duller-colored.
But here's where another question comes to mind: Are there universally attractive female features? Clearly not, as a quick survey by my friends reveals. But why is that? You don't see that kind of selectiveness in non-human animals. Female moose are going to mate with the toughest male with the largest antlers. Although my field experience in close to nill, I would think that females aren't saying to each other, "You know, I really like a male with big kneecaps." Females like antlers. Protoceratops females liked vaulted nasals on their males and big frills. Yowza! So what about humans? Why don't males across the species harbor similar desires for certain female features? Let's say that hourglass figures are an indication of fertility (which has been theorized!). Why would any man prefer a woman with anything but an hourglass figure? We could say the same thing about breasts: let's assume that large breasts are an indication of increased milk production (as has although been theorized). Why would natural selection favor anything below a C-cup?
Could this be an indication that natural selection isn't working in humans like it used to? Because medicine and technology keeps us all alive and breeding, those phenotypes which would otherwise be "bred out" of the gene pool stick around, and when you get to 6 billion+ people, sexual preference among males is also going to expand, too. Maybe when humans were hunting bison with spears and living in caves, sexual selection was more strongly universal, but as populations increased and lifespans lengthened, those factors were toned down. And today, you have every body type imaginable wandering the planet, and everybody will find somebody thanks to the miracle of overpopulation.
But there is still a very strong tendancy for women to be the "advertisers," which is interesting. I also wonder if, besides having a biological component, cultural factors differ between distinct human populations (more on that in future posts) in terms of who is competing for who?
More on this point in a future post. Feel free to call me a jackass in the comments, but this is interesting stuff. I like placing humans in the same scientific context that we would any other animal!