baby laughing chuckling

baby laughing chuckling

Babies can't possibly get a joke, so what causes their giggles? The answer might reveal a lot about the making of our minds, says Tom Stafford.

Somewhere between that first smile and that first recognizable syllable comes the magical sound of baby's first laughter. It may be a reaction to kisses on the belly, a tickling of toes, or a bouncy ride on Dad's knee. The triggers vary, but the laughter is inevitable. "In all cultures, it starts to develop in babies between 3 and 4 months," says Robert R. , PhD, psychology professor at the University of Maryland, Baltimore County, and author of Laughter: A Scientific Investigation (Viking). That said, don't worry if you haven't heard guffaws by 4 months. "As with all milestones, some babies may laugh a little later," says Sheila , MD, a clinical pediatrics professor at the University of Michigan's C.S. Mott Children's .