Harrington, Jesse RyanThis research demonstrates wide variation in tightness-looseness (strength of punishment and degree of permissiveness) at the state level in the United States, and its association with various ecological and historical factors, psychological characteristics, and state-level outcomes. Consistent with theory and past research, ecological and man-made threats--more natural disasters, greater disease prevalence, fewer natural resources, and greater external threat--predict increased tightness at the state level. Tightness is also associated with higher trait conscientiousness and lower trait openness. Compared with loose states, tight states have more social stability, indicated by lowered drug and alcohol use, lower rates of homelessness, and lower social disorganization. However, tight states also have relatively higher incarceration rates, greater discrimination and inequality, lower creativity, and lower happiness. In all, tightness-looseness provides a parsimonious explanation of the wide variation seen across the 50 states of the United States of America.enThesisPsychologycultureecologyindexnorms