Across three cultures and three languages, a simple question was posed: does the body's oldest social reflex belong to everyone? A study of 449 people from China, the Netherlands, and Greece found that ticklishness — its zones, its laughter, its involuntary surrender — is strikingly consistent across human populations, suggesting that beneath our cultural differences lies a shared evolutionary inheritance written into the skin itself. The research, published in Nature Human Behaviour, points not to touch receptor density or skin thickness as the cause, but to something more intuitive: the plac