Ancestral Diversity: A Socioecological Account of Emotion Culture.

Cultural differences in emotion expression, experience, and regulation can cause misunderstandings with lasting effects on interpersonal, intergroup, and international relations. A full account of the factors responsible for the emergence of different cultures of emotion is therefore urgent. Here we propose that the ancestral diversity of regions of the world, determined by colonization and sometimes forced migration of humans over centuries, explains significant variation in cultures of emotion. We review findings that relate the ancestral diversity of the world's countries to present-day differences in display rules for emotional expression, the clarity of expressions, and the use of specific facial expressions such as the smile. Results replicate at the level of the states of the United States, which also vary in ancestral diversity. Further, we suggest that historically diverse contexts provide opportunities for individuals to exercise physiological processes that support emotion regulation, resulting in average regional differences in cardiac vagal tone. We conclude that conditions created by the long-term commingling of the world's people have predictable effects on the evolution of emotion cultures and provide a roadmap for future research to analyze causation and isolate mechanisms linking ancestral diversity to emotion.