Science Fact: Men with high testosterone are more sexist, more aggressive, and yet more attractive.
Explanation: You've probably noticed by now that jocks and nerds tend to have different attitudes about things. Perhaps you noticed this while upside-down, with your head stuffed in a toilet, as the jock who held you there shouted "THIS WILL TEACH YOU TO WEAR A WIZARD SHIRT TO SCHOOL." Even if you haven't had run-ins like this, you know the stereotypes associated with both personalities; nerds join the Chess Club, and jocks hurl footballs at the Chess Club until it frantically disbands and is forced to relocate behind a dumpster. Jocks lift weights; nerds design a robot capable of lifting more weights; jocks draw boobs on the robot and throw it in the river. The circle of life continues.
Of course, these are just generalizations, but it should come as no surprise that scientists have pretty much confirmed them. "THIS JUST IN: JOCKS ARE MEAN," they have determined . "BREAKING NEWS: NERRRDDS" jocks will soon respond.
The Science: The most recent study on this topic surveyed a bunch of British guys and found that men who valued being muscular were also more likely to have sexist attitudes toward women. "Women often flirt with men just to hurt them!" they said. "If you throw holy water on a woman, she will evaporate," they presumably added. Also, a lot of these guys seemed to view being huge as a way to cope with feeling threatened—just maybe, they figured, if a girl rejected them, they could flex really hard until they were right and she was wrong. Scientists figure that these attitudes are partially related to body image and media consumption. (People who consume a lot of TV and movies tend to think dudes should be jacked, girls should be skinny, and everything should be exploding all the time.)
But it's not just about perceptions; it's about hormones, too. Older studies have repeatedly found that guys with high-testosterone traits (big jaws, increased muscle mass) are seen as more aggressive, and usually are more aggressive. These studies may not be all that shocking, given that they pretty much boil down to "jocks are jocks." And yet, women will continue to find them hotter, and nerds will continue to hide from them in the library, and this conflict will probably never be resolved. So what's a guy (or a girl, for that matter) to do?
So What Should I Do About It?
There are two things to keep in mind here. First, these are all generalizations—not every strong person secretly wants to punch all nerds to death and then treat a woman like an object. How a guy acts is obviously a better indicator of who he is than size of his biceps. But if you're female, it helps to be aware of these attitudes so you can watch out for them where they're more prevalent. (After all, sexism is more than just the blatant stuff.)
If you're a guy, all you really can do about these attitudes is set yourself up in opposition to them. Look, it's easy to see what's attractive about jocks—they're confident, they're in great shape, and they can approach someone and say hello without having a brain aneurysm. But women are also attracted to caring, reliable providers, which is something can be even if you're not constantly oozing testosterone. In the long run, it's more important to be a genuinely good dude without expecting anything in return than to be able to bench press a horse.