WEIRD
Acronym — Western, Educated, Industrialized, Rich, Democratic — coined by Joseph Henrich, Steven Heine, and Ara Norenzayan for the unusual, statistically outlying population that has dominated psychology's published research samples. Cross-cultural testing on the Müller-Lyer illusion and the ultimatum game across fifteen small-scale societies showed that fairness norms and perceptual habits long treated as universal are, in fact, culturally variable rather than a human baseline.