From a peck on the cheek to "get a room"-level PDA, kissing is everywhere, but for an activity common to almost every culture, it's remarkably underscrutinized, reports the Washington Post. One study of college student kissers found that men see kissing mostly as a precursor to sex, while women pay careful attention to taste and smell, possibly using kissing to assess potential mates.
Those assessments can be very detailed. "There's so much information exchanged when you kiss someone," says one anthropologist. "A huge amount of the brain is devoted to picking up information from the lips and tongue." One other tidbit: Men prefer to exchange lots of saliva. "Males like the very moist, wet open-mouth kisses," said a researcher. "We didn't expect that."