Why We Love

What scientists, not to mention the rest of us, want to know is, What makes us go so loony over love? The more scientists look, the more they're able to tease romance apart into its its individual strands--the visual, auditory, olfactory, tactile, neurochemical processes that make it possible.

read more from Time Magazine digg story

If it's easy for a glance to become a kiss and a kiss to become much more, that's because your system is trip-wired to make it hard to turn back once you're aroused. That the kiss is the first snare is no accident.

Not only does kissing serve the utilitarian purpose of providing a sample of MHC [something about chemical makeup that you'll have to read the whole article to understand], but it also magnifies the other attraction signals--if only as a result of proximity. Scent is amplified up close, as are sounds and breaths and other cues. And none of that begins to touch the tactile experience that was entirely lacking until intimate contact was made. "At the moment of a kiss, there's a rich and complicated exchange of postural, physical and chemical information," says Gallup. "There are hardwired mechanisms that process all this."

What's more, every kiss may also carry a chemical Mickey, slipped in by the male. Though testosterone is found in higher concentrations in men than in women, it is present in both genders and is critical in maintaining arousal states. Traces of testosterone make it into men's saliva, particularly among men who have high blood levels of the hormone to start with, and it's possible that a lot of kissing over a long period may be a way to pass some of that natural aphrodisiac to the woman, increasing her arousal and making her more receptive to even greater intimacy.