Eugenics and the Indeterminacy of Genetic Determinism

2022
School of Social Science Occasional Papers.

This essay follows the historical trajectory from the eugenic projects of one hundred years ago to today’s molecular behavior genetics (sociogenomics). In so doing, it demonstrates that, as scientists have developed more precise ways to measure the influence of DNA on social outcomes, those influences have paradoxically become more and more indeterminate, and this indeterminacy has supported a range of new eugenic projects. In the mid-nineteenth century, Francis Galton hypothesized that social outcomes were nearly entirely driven by biological inheritance. Scientists have worked since then to validate his claims, but have instead turned up more and more evidence that biological inheritance plays a much smaller role than Galton believed, and that the effects of genetics are inseparable from those of a person’s social, biological, and natural environment. Nonetheless, molecular behavior geneticists present their research to the public as if it indicated a decisive role for genetics in creating our social world, and advocate for policies premised on that overdrawn conclusion. The determinacy (and sometimes outright determinism) of scientists’ public statements about the genetic causes of social outcomes is therefore at odds with the indeterminacy revealed by their own science and that of others.