You, the reader, are probably a guy, and you are probably interested in dating girls, who are probably girls. At the risk of generalization, this feature will deal with ways that guys can attract and hold onto girls, using facts that come from scientists.
Science Fact: Girls are more attracted to guys who are relaxed than to guys who are all masculine and jocky.
Explanation: School dating often feels like an impossible contest. You'll engage all of your skills, all two of them, to win some girl's attention, only to find out she's dating some meaty golem who is clearly just going to suplex her into a garbage can when he's done with her. His testosterone grants him muscle mass, facial hair, and the ability to throw a football, while you have no muscle mass, no facial hair, and the ability to be hit in the face with a football, which sends you directly to the hospital or morgue. Life is terrible.
But wait! As it turns out, the Angry Punching Hormone (testosterone) is actually less important to women than the lack of the Girlish Shrieking Hormone (cortisol).
The Science: Researchers asked a bunch of dudes to spit into some cups, which is just one of many requests you can make of total strangers if you own a lab coat. They then showed girls pictures of these guys, presumably not taken while they were spitting, and asked them to rate the guys' faces for overall attractiveness. Behind the scenes, they measured the guys' levels of testosterone and cortisol.
Testosterone—whose function you already know—didn't significantly influence these hotness ratings. What girls did find hot was dudes with low cortisol—the hormone produced when stressed, or scared, or when you are a girl who is taking birth control pills while working out (a situation unlikely to apply to you). In other words, being macho turned these girls on less than being stressed turned them off. To keep random hot guys from tipping the balance of the study one way or the other, researchers did it again with frightening composite faces that illustrated cortisol-based or testosterone-based traits. Women again looked at the composite faces linked to low cortisol levels and were able to say, with apparent seriousness, "Why yes, I prefer this expressionless mannequin face," demonstrating that women have an opinion on which of two floating disembodied heads is hotter, and therefore are not reliable indicators of anything whatsoever.
So What Should I Do About It?
Well, the stuff you'd think would reduce your stress hormone is probably going to reduce your stress hormone. Laughing, getting a massage, and generally feeling like life is as snuggly as a bunny kissing a puppy will all do that. If you're angrily stamping your feet and demanding a more definitive solution, then there's your problem, but we happen to have one for you anyway.
Scientists totally unrelated to this study found that if you take a mixed sampling of people, then pose some of them like they're the Boss of Life and pose others like they're slouchy emo mole people, the first group will see an increase in testosterone and a decrease in cortisol. This study wasn't testing guys who already naturally sat in commanding or sheepish poses—the poses themselves literally changed the kind of hormone goo their brains made, which we will grant is not a very scientific analysis of these findings, but we just find it exciting, is all.
So you can actually alter your brain chemistry, which in turn alters your physical traits, which in turn lands you a pile of cheerleaders, just by acting like you're not embarrassed to exist. If you're chilling confidently and thinking "Hey, ladies, I wouldn't be an instantly regrettable mistake!" then they just might reach the same conclusion.
Anyone willing to test this out?