Why do we laugh? Is there any evolutionary significance? Well, instead of pondering about these questions… why not tickle a primate to find it out?
Humans aren’t the only ones who like it in the armpit. Our fellow great apes — orangutans, chimps, bonobos and gorillas — also squeal in response to tickling, and new research shows this behavior may be the evolutionary root of human laughter.
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Laughter is a key component of social interaction in humans. Humans are 30 times more likely to laugh when in the company of other humans than not, and tickling is inherently social — no animal is capable of tickling itself. Understanding the origins of laughter can also lend insight to the evolution of language, as both behaviors involve breath control and vocal cord vibrations.
References
Human Laughter Echoes Chimp Chuckles [Wired]
Ross MD, Owren MJ, Zimmermann E. Reconstructing the Evolution of Laughter in Great Apes and Humans. 2009 June [Current Biology]