A psychologist explains the evolutionary and psychological roots of laughter, and what an infant’s giggles teach us about how adults bond. There’s nothing quite like bearing witness to a baby’s first ...

Humor has always been subjective. Where some people prefer the physical comedy of Jim Carrey, others may find the dry approach of Albert Brooks preferable. Babies, of course, are not big on subtlety.

Few things are as heartwarming as hearing a baby's first laugh. I’ve experienced that moment with four children of my own, and that tiny, infectious sound isn’t just a special memory; it also marks a ...