Social Psychology in Societies of Strangers

Many of us live in "societies of strangers": cultural groups with large populations and high levels of relational and residential mobility. People in these societies have evolved institutions and social norms that promote cooperation and coordination, but I argue that they have also evolved a new kind of social psychology-one designed to infer what is happening inside other people's heads. I review new evidence suggesting that people in societies of strangers use more abstract psychological categories, allowing them to make a wide range of inferences about social partners after a single observation. I also extend this argument to explain cultural variation in various inference strategies, including the correspondence bias, halo effect, intention-based moral judgment, and stereotyping. The last part of my argument focuses on the role of language in helping people develop and transmit inference heuristics. Words like "moral," "angry," and "chivalrous" represent psychological categories that formalize inferences between different states and traits. Analyses of how language varies across time and cultures are more consistent with an inference-based account than with popular universalist accounts of emotion, personality, and moral categories. Appreciating the cultural evolution of inference heuristics provides new hypotheses about how social psychology has changed over the long arc of history and about the effects of more recent social network expansions involving globalization and social media.