Sep 07, 2016 12:47 AM GMT
NYT: Unpredictability is the key element of tickling, which is why you cannot tickle yourself.
The evolutionary purpose of tickling, according to Davila-Ross, is to promote bonding within a social group — between playmates, say, or parents and offspring. “Do not try to tickle a stranger,” she says. More intimate relationships yield more successful tickling sessions. Scientists divide tickling into two types: knismesis, a light, feather-type touch across the skin that can induce a shiver or twitch, and gargalesis, a repeated probing of sensitive areas like ribs, bellies, necks and the undersides of feet. If you’re trying to elicit uncontrolled laughter, go for gargalesis.