Tightness–looseness across the 50 united states

Significance The 50 states of the United States of America show great diversity in ecological and historical conditions, personality characteristics, and outcomes. Still, little insight exists that explains this variation. We argue that there is a common principle by which we can understand these differences: namely, that the states differ in tightness (many strongly enforced rules and little tolerance for deviance) versus looseness (few strongly enforced rules and greater tolerance for deviance). We develop a valid and reliable state-level tightness–looseness index, provide state rankings, and show how tightness is related to ecological and man-made threats, personality characteristics, and state-level outcomes. Ultimately, this substantiates theory suggesting that tightness–looseness is an adaptation to local environments and, therefore, is beneficial in understanding cultural variation across numerous levels of analysis.