This article explores differences between "tight" cultures ("have many strong norms and low tolerance of deviant behavior") and "loose" cultures ("have weak social norms and high tolerance of deviant behavior"). The tightness-looseness measure manifests in a myriad of macro and micro phenomena, from governance and religiosity to individual psychological processes. This study investigates these phenomena in modern nations rather than traditional societies. Potential ecological, historical, and socio-political predictors of tightness-looseness are also examined.

This article examines the relationship between the tightness-looseness of a culture and the variation of COVID-19 cases and deaths through October 2020. With COVID-19 data retrieved from Our World in Data from 57 countries with tightness-looseness figures, the article found the cultures with high levels of tightness had fewer COVID-19 cases and deaths when compared to countries with high levels of looseness. Results suggest support of the evolutionary game theoretic model proposing that people in tight cultures may cooperate with more urgency when under collective threat than people in loose cultures.

Authors contend that many of the differences across the 50 states can be attributed to the degree to which social entities are "tight" (have many strongly enforced rules and little tolerance to deviance) or "loose" (have few strongly enforced rules and greater tolerance for deviance). Significant correlations were found between many state characteristics and tightness-looseness.

This article builds on previous cross-country and cross-state research into Tightness-Looseness (TL) theory, which proposes relationships between the incidence of ecological threat and cultural tightness, as well as tightness’ downstream effects on belief in a moralizing high god, inter-group contact and authoritarian leadership. To evaluate the generalizability of TL theory beyond complex cultures, the authors test these relationships among 86 nonindustrial societies from the ethnographic record. A structural equation model is presented of the results for nonindustrial societies; it is generally in accord with previous findings from more complex societies. Because the nonindustrial sample is more variable, they also look at relationships between societal complexity and kinship heterogeneity, aspects that vary in nonindustrial societies.

This article explores the following questions: What environmental and cultural factors might explain variation in prejudice across cultures? Do these factors explain the intention to vote for nationalist politicians? The authors perform seven studies, focusing on the link between cultural tightness and the rise of prejudice in cultures. They theorize that cultural tightness is positively correlated with the rise of prejudice against people perceived as disrupting the social order. From this theory, they suggest three hypotheses: 1) cultural variation in tightness is related to cultural variation in prejudice, 2) cultural tightness is related to the support for nationalist politicians, and 3) cultural tightness is a link between ecological threats and prejudice. The results support these hypotheses, offering a cultural evolutionary perspective on prejudice.