Weak Genetic Explanation 20 Years Later: Reply to Plomin et al. (2016).

Plomin, DeFries, Knopik, and Neiderhiser (2016, this issue) are correct in their assertion that many discoveries of behavior genetics have proven to be robust and replicable. I note, in contrast, that more specific assertions about the role of genetics in the development of behavior have failed to replicate. Reflecting on why more general findings replicate better than specific ones sheds light on the difficulties of studying complex human development and on the role played by genes in determining its course.