Stephen Jay Gould on Evolutionary Psychology

Stephen Jay Gould (1941–2002) was a highly influential paleontologist, evolutionary biologist, and historian of science. While not an evolutionary psychologist himself, Gould became one of the most prominent and articulate critics of certain approaches within the field, particularly those he characterized as overly adaptationist or reductionist. His extensive writings, often aimed at a broad public audience, shaped much of the debate surrounding the theoretical underpinnings and empirical claims of evolutionary psychology from the 1970s through the early 2000s.

Gould's Core Critiques

Gould's criticisms of evolutionary psychology stemmed largely from his broader views on evolutionary theory, which emphasized contingency, historical constraints, and the importance of non-adaptive evolutionary processes. He contended that many evolutionary psychologists engaged in a form of "ultra-Darwinian" or "Panglossian" adaptationism, wherein every human trait or behavior is assumed to be a direct product of natural selection for a specific function. This perspective, he argued, overlooked alternative explanations for the origin and persistence of traits.

Adaptationism and Spandrels

Gould, along with Richard Lewontin, famously introduced the concept of "spandrels" in their 1979 paper, "The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme." A spandrel, in architecture, is the triangular space formed by the intersection of two arches. Gould and Lewontin argued that these spaces are not designed for a primary purpose but are rather unavoidable byproducts of the architectural decision to place arches. They extended this metaphor to biology, suggesting that many biological traits, including human cognitive or behavioral features, might not be direct adaptations but rather exaptations (traits co-opted for a new use, having evolved for another purpose or as a byproduct) or spandrels (non-adaptive byproducts of other adaptive features).

Gould applied this critique directly to evolutionary psychology, arguing that many proposed psychological adaptations—such as specific cognitive modules for mate choice or social exchange—might instead be spandrels or exaptations of more general cognitive capacities. For example, he suggested that human artistic ability or religious belief might not be direct adaptations for survival or reproduction but rather emergent properties or byproducts of other large-brained capacities, such as symbolic thought or theory of mind. To Gould, assuming direct adaptation for every complex trait was an unfalsifiable narrative exercise, or "just-so story," rather than rigorous scientific inquiry.

Modularity and Reductionism

Gould also expressed skepticism about the strong modularity hypothesis often associated with evolutionary psychology, particularly as articulated by researchers like Leda Cosmides and John Tooby. This hypothesis posits that the mind is composed of numerous domain-specific, functionally specialized cognitive modules, each evolved to solve a particular recurrent problem faced by ancestral humans. Gould viewed this as an overly reductionist approach that failed to account for the integrated and flexible nature of human cognition. He argued that such a view underestimated the role of general learning mechanisms and cultural transmission in shaping human behavior.

The Problem of Evidence

A recurring theme in Gould's critique was the perceived lack of sufficient empirical evidence for many evolutionary psychological claims. He argued that it was often difficult, if not impossible, to reconstruct the specific selective pressures that might have shaped a particular cognitive module in the distant past. He emphasized the danger of post hoc explanations, where a current trait is explained by an imagined past selective scenario without independent evidence for that scenario. Gould maintained that the burden of proof for adaptation lay with those proposing it, and that alternative explanations (e.g., drift, phylogenetic constraint, spandrels) should be rigorously considered.

Responses and Debates

Evolutionary psychologists and their allies responded to Gould's critiques in several ways. Many acknowledged the conceptual validity of spandrels and exaptations but argued that Gould overstated their prevalence and underestimated the power of natural selection to shape complex traits. For instance, Steven Pinker (1997) contended that while spandrels exist, many complex and well-engineered features of organisms, including psychological ones, are indeed adaptations. Pinker and others argued that Gould's critique of adaptationism was often misdirected, as evolutionary psychologists do not claim every trait is an adaptation, but rather seek to identify those that are.

Regarding the "just-so story" accusation, proponents of evolutionary psychology argued that their hypotheses are testable, often through cross-cultural studies, experimental designs, and comparisons with non-human primates. They maintained that the inference of past selection pressures is a standard practice in evolutionary biology and that the challenge lies in developing rigorous methods to test these inferences, which they claimed to be doing.

The debate between Gould and his intellectual opponents also touched upon the nature of scientific explanation. Gould advocated for a pluralistic approach to evolutionary biology, acknowledging multiple levels and modes of explanation. He believed that an overemphasis on adaptationism led to a narrow and incomplete understanding of life's history and complexity. While Gould's direct engagement with evolutionary psychology was often critical, his broader work encouraged greater methodological rigor and a more nuanced understanding of evolutionary processes, influencing how evolutionary explanations are framed and scrutinized within and beyond the field.