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: Women become more interested in a guy if they see other people acting interested in him, too.
Explanation: Stop us when this sounds familiar: you like a girl, but she is so uninterested in you that she drives right over you in her car, because you are basically invisible to her. "I love yoouuu," you gasp, crushed beneath her Honda Civic, but she can't hear you; she's busy chatting with Pierce McQuarterbeard, the most popular boy in school, who has piercing eyes, innate quarterbacking talents, and the ability to grow a huge beard, if he so chooses. "Curse you, McQuarterbeard!," you hiss, as the incredibly popular couple drives off into the sunset, leaving your nerdy corpse to imagine all the wonderful times and makeouts they will undoubtedly share.
Well, this is very sensible behavior on an evolutionary level—theirs, not yours. Cliquish high school popularity may feel tremendously unfair (at least if you're not one of the ones benefiting from it), but at its most basic level, popularity is something we rely on to determine whom it's safe to hang around with. If a guy walks into a room and everyone breaks out into huge smiles when they see him, and then a second guy walks in giggling manically and licking a knife, it's basic human nature to prefer the guy the rest of the room already approves of. The same principle applies, in some rather unexpected ways, to dating.
The Science: Some Indiana University researchers did an experiment based on the idea of "mate choice copying," when an organism is more attracted to a potential mate if other organisms have already mated with it. This is a behavior in which all kinds of hilarious-sounding animals engage, from sailfin mollies to deep-snouted pipefish, so it is clearly fantastic.
The researchers showed participants some videos of speed-dating interactions between guys and girls, then asked the participants to rate their romantic interest in the people onscreen. They found that when the onscreen girl acted like she was bored to death of the onscreen guy, female viewers were also uninterested in him, but if the onscreen girl acted captivated, suddenly female viewers found the guy amazing. Their interest was at least partially influenced by whether other people were interested, and in some cases, that was all it took to make them go from yawning in boredom to kissing their monitors in uncontrollable lust (or so we imagine).
For the record, men do the same thing. In the study, the only difference was that men didn't become less interested if the onscreen guy was less interested. They did, however, become more interested if the onscreen guy was hotter, so make of that what you will.
So What Should I Do About It?
Obviously, all you need to do is become incredibly popular. That, or learn some jokes.
A while ago, a French study started with the premise that humor is attractive, but wanted to determine what part of humor was attractive. Researchers had female participants sit near a table where an attractive young guy was hanging out with friends; the guy was either 1.) telling jokes and provoking everyone's laughter or 2.) being one of the guys laughing. When the guy approached the female participant afterward, the girl was three times as likely to give him her phone number if he'd been the one telling the jokes.
The same basic idea is at work in both of these situations—people see you making a good impression on other people, and they go "HE'S MINE, I SAW HIM FIRST" and clamber over each other to get at you. Humor just happens to be one of the best ways to make that impression. And if humor is beyond your ability, girls who value humor also tend to value intelligence, so you might as well just tell them your best Werner Heisenberg joke and hope for a miracle.
Does your personal experience line up with the science?