Not in Our Genes

The Argument

Not in Our Genes: Biology, Ideology, and Human Nature (1984) by geneticist Richard Lewontin, neurobiologist Steven Rose, and psychologist Leon Kamin presents a comprehensive critique of what its authors term 'biological determinism.' This concept, central to their argument, posits that an individual's character, intelligence, temperament, and social standing are primarily or entirely determined by their genes or other biological factors. The book specifically targets sociobiology, then a nascent field, as well as genetic explanations for intelligence, mental illness, and sex differences.

The authors argue that biological determinism is not merely a scientific error but also an ideology with significant social and political implications. They contend that by attributing social inequalities, such as class stratification, racial disparities, or gender roles, to inherent biological differences, biological determinism implicitly justifies the status quo and deflects attention from social and economic causes. This, they suggest, serves to legitimize conservative political agendas by presenting social problems as immutable biological facts rather than solvable societal issues.

A key aspect of their critique involves dissecting the methodologies and assumptions of genetic studies, particularly those concerning intelligence (IQ). Kamin, in particular, had previously published extensive critiques of twin and adoption studies used to estimate the heritability of IQ, arguing that methodological flaws and unexamined environmental confounds inflated genetic estimates. In Not in Our Genes, these arguments are expanded, challenging the very concept of a fixed, measurable intelligence that can be meaningfully inherited. They emphasize the profound influence of environment, culture, and social context on cognitive development and behavior, arguing against the idea of a universal 'human nature' dictated by genes.

Lewontin, a population geneticist, contributed significantly to the critique of heritability estimates, particularly the misunderstanding that high heritability within a population implies genetic causation for differences between populations. He famously used the analogy of seeds planted in different soils to illustrate that even if the variation in height within each pot is entirely genetic (high heritability), the difference in average height between pots can be entirely environmental (due to soil quality). This distinction is crucial for understanding their rejection of genetic explanations for group differences in traits like IQ.

Historical Context and Reception

Not in Our Genes emerged from a period of intense debate surrounding sociobiology, particularly following the publication of E.O. Wilson's Sociobiology: The New Synthesis in 1975. Wilson's work, which attempted to explain social behaviors across species, including humans, through an evolutionary lens, sparked considerable controversy. Critics, including Lewontin and Rose, formed the Sociobiology Study Group, arguing that Wilson's extension of sociobiological principles to human behavior was reductionist, deterministic, and politically dangerous.

The book was widely reviewed and became a touchstone for critics of biological determinism and proponents of social constructionism. Supporters lauded its rigorous scientific analysis combined with a trenchant critique of the ideological underpinnings of certain scientific claims. They appreciated its emphasis on the interplay between biology and environment, and its call for a more nuanced, dialectical understanding of human development that avoids both genetic reductionism and environmental determinism.

However, Not in Our Genes also faced significant criticism. Some reviewers accused the authors of misrepresenting sociobiology, arguing that Wilson and other sociobiologists did not deny environmental influence but sought to understand the evolutionary origins of behavioral predispositions. Critics also contended that the authors sometimes conflated scientific inquiry with political ideology, implying that any attempt to find biological bases for human traits was inherently conservative or dangerous. For example, some argued that the book's strong anti-reductionist stance could hinder legitimate scientific investigation into the biological components of complex traits.

Another line of critique focused on what was perceived as an overemphasis on social and environmental factors to the exclusion of biological ones, leading to an 'environmental determinism' that was equally problematic as the biological determinism they opposed. Critics also pointed out that the book, while strong in its critique, offered fewer concrete alternative frameworks for understanding the complex interaction of genes and environment in human development.

Enduring Influence and Open Questions

Despite the criticisms, Not in Our Genes remains a highly influential work in the history of science, particularly in fields like science and technology studies, sociology of science, and critical theory. It helped to solidify a critical perspective on the social implications of scientific research and contributed to a broader awareness of how scientific findings can be used to support or challenge political ideologies. The book's arguments continue to resonate in contemporary debates about the role of genetics in explaining human behavior, health, and social outcomes, particularly in the era of genomics and personalized medicine.

The book's central message — that complex human traits are not 'in our genes' in a simple, deterministic sense — has largely been absorbed into mainstream scientific thought, albeit often in more nuanced forms. Few contemporary scientists advocate for a purely deterministic genetic model of human behavior. Instead, the focus has shifted to gene-environment interactions, epigenetics, and developmental systems theory, which emphasize the dynamic interplay between biological predispositions and environmental factors throughout an individual's life. However, the vigilance against reductionist explanations and the ideological misuse of scientific findings, as championed by Lewontin, Rose, and Kamin, remains a pertinent concern in evolutionary psychology and related fields.