The emergence of COVID-19 dramatically changed social behavior across societies and contexts. Here we study whether social norms also changed. Specifically, we study this question for cultural tightness (the degree to which societies generally have strong norms), specific social norms (e.g. stealing, hand washing), and norms about enforcement, using survey data from 30,431 respondents in 43 countries recorded before and in the early stages following the emergence of COVID-19. Using variation in disease intensity, we shed light on the mechanisms predicting changes in social norm measures. We find evidence that, after the emergence of the COVID-19 pandemic, hand washing norms increased while tightness and punishing frequency slightly decreased but observe no evidence for a robust change in most other norms. Thus, at least in the short term, our findings suggest that cultures are largely stable to pandemic threats except in those norms, hand washing in this case, that are perceived to be directly relevant to dealing with the collective threat. Tightness-looseness theory predicts that social norms strengthen following threat. Here the authors test this and find that, after the emergence of the COVID-19 pandemic, hand washing norms increased, but no evidence was observed for a robust change in most other norms.

Did cultures change shortly after, and in response to, the COVID-19 outbreak? If so, then in what way? We study these questions for a set of macro-cultural dimensions: collectivism/individualism, duty/joy, traditionalism/autonomy, and pro-fertility/individual-choice norms. We also study specific perceptions and norms like perceived threats to society (e.g. immigration) and hygiene norms. We draw on Evolutionary Modernization Theory, Parasite Stress Theory, and the Behavioural Immune System, and existing evidence, to make an overarching prediction: the COVID-19 pandemic should increase collectivism, duty, traditionalism, conformity (i.e. pro-fertility), and outgroup prejudice. We derive specific hypotheses from this prediction and use survey data from 29,761 respondents, in 55 cities and 43 countries, collected before (April–December 2019) and recently after the emergence of COVID-19 (April–June 2020) to test them. We exploit variation in disease intensity across regions to test potential mechanisms behind any changes. The macro-cultural dimensions remained stable. In contrast, specific perceptions and norms related to the pandemic changed: norms of hygiene substantially increased as did perceived threats related to disease. Taken together, our findings imply that macro-cultural dimensions are primarily stable while specific perceptions and norms, particularly those related to the pandemic, can change rapidly. Our findings provide new evidence for theories of cultural change and have implications for policy, public health, daily life, and future trajectories of our societies.

Social learning is common in nature, yet cumulative culture (where knowledge and technology increase in complexity and diversity over time) appears restricted to humans. To understand why, we organized a computer tournament in which programmed entries specified when to learn new knowledge and when to refine (i.e. improve) existing knowledge. The tournament revealed a 'refinement paradox': refined behavior afforded higher payoffs as individuals converged on a small number of successful behavioral variants, but refining did not generally pay. Paradoxically, entries that refined only in certain conditions did best during behavioral improvement, while simple copying entries thrived when refinement levels were high. Cumulative cultural evolution may be rare in part because sophisticated strategies for improving knowledge and technology are initially advantageous, yet complex culture, once achieved, favors conformity, blind imitation and hyper-credulity.

We examine the effects of a year-long national-scale professional development (PD) program on mathematics instructional quality. In contrast to previous studies examining the effects of this program on instruction by comparing before and after participation or participants and non-participants, we examine whether instructional quality changed during the program. More specifically, we conduct an analysis of 174 video-recorded mathematics lessons given by 52 teachers during their year of participation. Contrary to previous studies, the results demonstrate that the instructional quality did not improve over the course of the PD. We suggest that the explanations for the diverging results concern how, when, and to what extent instructional quality changes in PD programs. Specifically, we discuss how the explanations may illuminate the significance of PD duration for PD effects, and how these effects may be mediated by features concerning the PD content and the scale at which the program is implemented.

In general, people are influenced by the standards set forth by groups of others; however, the levels of such conformity vary between people and across cultures. Here, we investigated factors related to country-level personality profile conformity (i.e., person-culture personality fit) across similar to 5.9 million participants, residing in 57 different countries. We examined how each of the Big Five personality traits and cultural tightness are associated with variation in person-culture personality fit. We found that scoring higher in Extraversion, Agreeableness, and Conscientiousness and residing in a tight cultural context explains increased personality profile conformity, while scoring higher in Openness and Neuroticism and residing in a loose cultural context explains lower personality profile conformity. Furthermore, we found that Openness and Extraversion interact with cultural context to predict levels of personality profile conformity. These findings reveal that both dispositional and cultural factors correspond to the tendency to conform to country-level norms.

By examining the effects of a national-scale teacher professional development (PD) program on instructional practices and student mathematics achievement, we contribute to calls for empirical studies investigating the impacts of such programs conducted at scale. The program corresponds well with core critical features of high-quality teacher PD and mathematics instruction identified in the literature, and the results indicate that it has had a small but statistical significant impact on teachers' instructional practices. However, no effect was found for student achievement. These results raise questions as to the importance of the critical features and how programs incorporating all of them affect instructional practices and student achievement.

Emotions are linked to wide sets of action tendencies, and it can be difficult to predict which specific action tendency will be motivated or indulged in response to individual experiences of emotion. Building on a functional perspective of emotion, we investigate whether anger and shame connect to different behavioral intentions in dignity, face, and honor cultures. Using simple animations that showed perpetrators taking resources from victims, we conducted two studies across eleven countries investigating the extent to which participants expected victims to feel anger and shame, how they thought victims should respond to such violations, and how expectations of emotions were affected by enacted behavior. Across cultures, anger was associated with desires to reclaim resources or alert others to the violation. In face and honor cultures, but not dignity cultures, shame was associated with the desire for aggressive retaliation. However, we found that when victims indulged motivationally-relevant behavior, expected anger and shame were reduced, and satisfaction increased, in similar ways across cultures. Results suggest similarities and differences in expectations of how emotions functionally elicit behavioral responses across cultures.

Vaccine hesitancy is a threat to global health, but it is not ubiquitous; depending on the country, the proportion that have confidence in vaccines ranges from a small minority to a huge majority. Little is known about what explains this dramatic variation in vaccine confidence. We hypothesize that variation in religiosity may play a role because traditional religious teachings are likely to be incompatible with the specific magical/spiritual health beliefs that often undergird anti-vaccination sentiments. In analyses of publicly available data in 147 countries, we find that a country measure of religiosity is strongly positively correlated with country measures of confidence in the safety, importance, and effectiveness of vaccines, and these associations are robust to controlling for measures of human development (education, economic development, and health). The underlying mechanism needs to be examined in future research.