One thing we know about tickling: It makes us laugh. But why? And what exactly is it? Is it pain? Pleasure? Aristotle wrote about tickling all the way back in 350 B.C. Darwin did too, in 1872. But, of ...

Tickling may seem like child's play, but scientists are beginning to see it as something much deeper—a complex puzzle tied to human touch, laughter, and brain development. The sensation of being ...

NIJMEGEN, Netherlands — Ever try to tickle yourself? Go ahead, stroke your own armpit or foot sole right now. Feel absolutely nothing? That’s because your brain is playing a fascinating trick on you — ...