Short answers, pulled from the story.
Joseph Henrich, born in 1968, is an American anthropologist and professor of human evolutionary biology at Harvard University. He is best known for coining the concept of "WEIRD" populations in psychology, for cross-cultural experiments that challenged standard game theory, and for arguing that culture shapes human genetic evolution.
WEIRD is a backronym standing for Western, Educated, Industrialized, Rich, and Democratic. Henrich and his collaborators coined it to describe the narrow subset of populations most commonly used in psychological and behavioral research, arguing these groups are psychologically peculiar within the full global spectrum of human variation.
Henrich led teams of anthropologists and economists running behavioral experiments in diverse societies worldwide and found that the predictions of standard game theory failed across a wide range of human societies. Crucially, they failed in different ways in different places, indicating that economic behavior is shaped by local cultural environments rather than universal self-interest.
Henrich argues that the Catholic Church's medieval ban on cousin marriage broke apart extended kin networks, leaving nuclear families isolated and forcing them to build new voluntary associations for support. He contends this process generated the individualistic psychology that WEIRD populations display today.
Henrich argues that normative monogamy spread culturally because it reduces male-male competition within a group. With fewer men excluded from reproductive opportunities, groups experienced less internal conflict and gained an advantage in competition with other societies.
Henrich received the Presidential Early Career Award for Scientists and Engineers in 2003 and the Hayek Prize in 2022. He also held the Canada Research Chair in Culture, Cognition and Coevolution at the University of British Columbia before moving to Harvard.