I'm willing to bet the last time you thought of kissing as gross was back when you were a kid. It was also probably around the same time we girls thought you boys came with cooties. Then you grow up ...

Nobody knows when kissing emerged among humans. But the practice of plopping one's mouth on another human, whether in friendship or love, is not universal; which suggests culture, rather than instinct ...

Breakthroughs, discoveries, and DIY tips sent every weekday. Terms of Service and Privacy Policy. It may not be the most romantic thing to say, but kissing ...