Social norms are a defining feature of human psychology, yet our understanding of them is still underdeveloped. In this article, we present our own cross-cultural research program on tightness-looseness (TL)-which draws on field, experimental, computational, and neuroscience methods-to illustrate how going beyond Western borders is critical for understanding social norms' functions and their multilevel consequences. Cross-cultural research enables us to account for the universal features of norm psychology but also explains the great cultural diversity we see in social norms around the globe.
Keywords: culture; diversity; environment; individual differences; neuroscience.