Gender and culture shape prosociality more than heat stress in a five-country experiment

A consistent finding regarding human societies is that higher temperatures lead to antisocial behavior, including more crime, violence, aggression, and civil conflict. A large body of research documents this relationship at the societal level, but an understanding of the psychological and physiological mechanisms underpinning the effect of heat on antisocial behavior remains less understood. We present an experiment designed to isolate the impact of elevated temperatures on social preferences, namely egalitarianism, welfare maximization, selfishness, spite, and competitiveness. We exogenously varied temperatures across lab sessions in five countries in which randomly matched participants make incentivized distributional choices to others and decide whether to compete in a tournament. As an additional manipulation, we include a psychological stressor to potentially trigger an antisocial response when combined with higher temperatures. Our sessions were carried out with university student participants in Colombia, India, Kenya, Mexico, and the United States ( $N=1,636$ ). We find that despite a strong negative effect on mood, elevated temperatures had little or no effect on social and economic preferences across countries, especially in comparison to the substantial and significant correlations we find with gender and culture. Future research should more closely examine the alternative channels through which elevated temperatures negatively impact social behavior.