Home > Positioning > Persons > Richerson

Peter Richerson (1943–)

Richerson is an evolutionary biologist whose collaboration with Robert Boyd produced the theoretical framework for studying culture as an evolutionary process. Where Boyd contributes the mathematical modelling, Richerson contributes the ecological and empirical grounding — the recognition that human adaptation to diverse environments (from the Arctic to the tropics, from deserts to rainforests) cannot be explained by genetic adaptation alone. The timescales are too short and the environmental variation too rapid; cultural learning must be part of the explanation. Culture and the Evolutionary Process (1985) is the founding work; Not by Genes Alone: How Culture Transformed Human Evolution (2005) presents the case for a general audience.

Life

Born 1943. Undergraduate at Denison University. PhD in zoology at the University of California, Davis (1969), studying limnology — the ecology of lakes. The limnological training is significant: Richerson’s early work studied how lake ecosystems respond to environmental change on timescales of decades to millennia, which gave him a practical understanding of how populations adapt to variable environments. The step from ecological adaptation to cultural adaptation was natural: if lake ecosystems can show adaptive change on timescales too short for genetic evolution, so can human populations — and culture is the mechanism.

Professor of environmental science and policy at UC Davis (1969–2008). Emeritus since 2008 but continues to publish actively. Richerson’s institutional base in environmental science rather than anthropology or biology reflects the interdisciplinary character of the programme: cultural evolution draws on ecology, evolutionary biology, anthropology, and psychology, and no single department houses it comfortably.

Richerson has been explicit about the programme’s intellectual lineage: it begins with Darwin’s recognition that human behaviour is partly instinctive and partly learned, passes through the mid-century gene-culture co-evolution models of Luigi Luca Cavalli-Sforza and Marcus Feldman, and arrives at the dual-inheritance framework that Boyd and Richerson developed. The framework is explicitly non-memetic: culture is not gene-like replication but a population-level process with its own transmission dynamics.

The ecological argument for culture

Richerson’s distinctive contribution is the ecological case for why culture evolved. Humans occupy a wider range of environments than any other primate — environments that change on timescales (centuries, decades, years) far shorter than genetic evolution can track. Genetic adaptation is too slow; individual learning is too costly (trial-and-error in a harsh environment is dangerous). Cultural learning — copying the behaviour of successful or experienced individuals — is the solution: it allows populations to accumulate adaptive knowledge across generations without each individual needing to rediscover it.

The argument connects to the transmission biases: conformist bias is adaptive because it transmits locally adaptive behaviour (do what the locals do); prestige bias is adaptive because it identifies individuals who have navigated the local environment successfully (copy the expert). The biases are not rational calculations; they are evolved heuristics — psychological dispositions shaped by genetic evolution to make cultural learning efficient.

Not by Genes Alone (2005) develops the argument that culture is not an add-on to genetic evolution but a co-equal inheritance system that has transformed human evolution. The key claim: “Culture is as much a part of human biology as the upright posture.” The interaction between the two systems — gene-culture coevolution — produces outcomes that neither system could produce alone.

Where Richerson stops

The ecological argument for culture is compelling at the species level (humans need culture because we occupy variable environments) but does not fully specify the cultural dynamics at the population level. Why do particular cultural norms arise in particular populations? Why do some norms persist and others disappear? The dual-inheritance framework provides the formal tools to model these dynamics, but the empirical data to parameterise the models — the actual strengths of conformist bias, prestige bias, and between-group cultural variation in specific populations — are often unavailable. The framework is strong on mechanism and weak on measurement.

Richerson’s emphasis on ecological context distinguishes his approach from more purely theoretical treatments of cultural evolution, but it also limits the framework’s applicability to domains where the ecological grounding is clear. Cultural practices in domains remote from ecological adaptation — art, religion, political ideology, intellectual traditions — are harder to fit into the adaptive-ecology framing. Whether the dual-inheritance framework extends naturally to these domains or requires substantial modification is an open question that Richerson has acknowledged but not fully addressed.

Key works

See also: Boyd · Dawkins · Sperber · Darwinism