Joseph Henrich

American anthropologist and cultural evolutionary theorist (b. 1968), Ruth Moore Professor and chair of the Department of Human Evolutionary Biology at Harvard. Trained at UCLA in anthropology and economics; previously at the University of British Columbia. A leader of the gene-culture co-evolution research program, which treats human evolution as a joint biological-cultural process operating on much shorter timescales than classical evolutionary theory assumed.

Intellectual program

Henrich’s career has had two principal arcs, the second growing out of the first.

Phase 1: cultural evolution generally. The Secret of Our Success (2015) makes the case that the distinctive human capacity is not raw intelligence but cumulative cultural learning — our ability to acquire, refine, and transmit complex behaviors and tools across generations through high-fidelity social learning. The framework draws on cross-cultural fieldwork (Henrich’s earlier work was with the Machiguenga and other Amazonian populations), behavior-genetic and twin-study evidence, and computational models of how cultural learning shapes selection pressure on cognition. The book is the systematic statement of the gene-culture co-evolution program.

Phase 2: WEIRD psychology and its causes. The WEIRDest People in the World (2020) applies the cultural-evolution framework to a specific historical question: why are populations descended from medieval Western Christendom psychologically unusual on cross-cultural psychology measures? The answer, in Henrich’s account, is the medieval Catholic Church’s Marriage and Family Program — the systematic prohibition over ~500–1500 CE of cousin marriage (eventually out to 6th-degree cousins), polygyny, concubinage, levirate remarriage, arranged child marriage, and adoption-for-inheritance. These rules dissolved the kin-based institutions that had governed most pre-modern human societies, forcing Europeans to rely on impersonal institutions (chartered cities, merchant guilds, universities, markets, the Church itself) and selecting — culturally and perhaps biologically — for the individualist, analytic, impersonal-trust, guilt-oriented psychology that contemporary cross-cultural psychology measures call “WEIRD.” The empirical core is the Schulz et al. 2019 Science paper, which documents sub-national correlations between centuries of Church exposure and contemporary WEIRD-ness, both within Europe and in colonial settler populations.

The argument is in some sense the most ambitious causal story in the modern Great Divergence literature: a multi-century chain stretching from medieval canon law through population-cultural transformation to early-modern institutional-economic outcomes to the modern divergence between Europe and the rest. It is held together by the gene-culture co-evolution framework and the empirical psychological measures, but it stacks more causal steps than most economic historians are comfortable with.

Reception and contestation

Henrich’s reception is bimodal. The cross-cultural psychology community has broadly accepted the WEIRD framework as a useful corrective — psychology measures derived from Western university-student samples should not be assumed to generalize to all humans; the historical contingency of WEIRD psychology is now textbook. The historical-causal claim that the medieval Church Marriage Program produced WEIRD psychology and that WEIRD psychology causes modern economic divergence is much more contested. Critiques: the causal chain is long and fragile; the historical claim about the comprehensiveness of Church Marriage Program enforcement is contested; the WEIRD-measures-cause-divergence claim sits uncomfortably close to older racialist framings even as it explicitly resists them.

Within economic history specifically, the framework remains heterodox. Within the broader social-science ecosystem (political science, sociology, comparative cultural psychology), it has become part of the conversation.

Associated positions

• WEIRD: kin to individualist — primary proponent.
• Demographic & family-system divergence — closely related argument from a different angle.

Key works

• Why Humans Cooperate: A Cultural and Evolutionary Explanation (2007, with Natalie Henrich).
• The Secret of Our Success: How Culture is Driving Human Evolution, Domesticating Our Species, and Making Us Smarter (2015).
• With Jonathan Schulz, Duman Bahrami-Rad, and Jonathan Beauchamp: “The Church, Intensive Kinship, and Global Psychological Variation” (Science, 2019).
• The WEIRDest People in the World: How the West Became Psychologically Peculiar and Particularly Prosperous (2020).