Hereditarianism: a century of the science of inequality

Hereditarianism, the belief that genetic factors significantly influence differences in behavioral traits and social outcomes, remains relevant in the age of polygenic embryo screening and social science genomics. Although early twentieth-century monogenic versions of hereditarianism-suggesting specific genes for traits like feeble-mindedness, nomadism, and pauperism-may now seem outdated, similar reasoning persisted into the early twenty-first century through candidate gene studies. With the advent of high-resolution genomic association studies, the understanding of complex traits has shifted toward a massively polygenic architecture, moving away from the "gene for X" paradigm. Nevertheless, the aspiration to identify purely genetic causes persists, and a more nuanced form of hereditarian theory continues to exist. This paper explores the evolution of hereditarianism in its various forms, examining its connections to racism and anti-egalitarian politics. In a sense, this work is an extension of the twentieth century critique of hereditarianism, in line with key figures like Richard Lewontin and Stephen Jay Gould. The paper begins with early twentieth-century eugenics and the hereditarian approach to IQ in the United States, progresses to modern scientific racism, and concludes with an evaluation of causal claims in contemporary social science genomics. A consistent theme across these periods and fields is the belief in the potential for genetic explanations of social inequalities both within and between groups.