The Social and Historical Conditions of Heritability

Daniel Navon, University of California, San Diego
Aaron Panofsky, University of California, Los Angeles

We tend to think of heritability—the variation in a phenotype that can be attributed to genetic factors—as both fixed and intrinsically biological. But even though the genetic material inherited through our germ cells is mostly immutable, its impact on who we are is not. Heritability in humans is always contingent upon an array of shifting sociological factors. The reason lies in an often-overlooked scope condition for heritability estimation: it is the variation in a trait or disease outcome attributable to genetic variation within a population. We argue that this last caveat represents a powerful mandate for grappling with a series of local historical conditions and social forces before even thinking about questions of heritability (rather than merely the way they “mediate” the genetic contribution to a phenotype). After all, populations are comprised of complex entanglements of genetically variable individuals that change in all sorts of ways as they interact with the environment. Meanwhile, our modes of classifying them are constantly in flux as well. As researchers in fields like behavior genetics have long acknowledged (but often ignored), heritability estimates change along with the population and/or environment. Drawing on existing research on smoking, IQ and educational attainment, and autism, we show how historical transformations in cultural norms, socioeconomic status/stratification, demography, and classification can all shape the heritability of important categories of human difference. By way of conclusion we bring in the new field of “sociogenomics” and the recent turn towards polygenic risk scores, and discuss the inherent dangers of trying to get at heritability in humans without rigorous historical social science to guide the way.

No extended abstract or paper available

 Presented in Session 127. Expertise at the Intersection of Biology and Social Science