A kiss is one of the simplest gestures humans share, yet it carries an extraordinary depth of meaning. It can express love, longing, comfort, passion, reverence, reconciliation, and even farewell.

Kissing-like behaviors exist across the animal kingdom. But why? A scientist explains why humans are so drawn to each other's lips, and a photographer documents the power of a kiss. Among the many ...

Is it in his kiss? Oh, yes. Osculation, the scientific term for kissing, in many ways says everything about your compatibility with your mate and the health of your relationship. We asked scientist ...