Chunk #19 — Basic methodology of genetic epidemiology: an overview of twin studies — Principle 4: Our genetic predispositions shape our behavior in part by influencing our environments
et al., 2008a; McGue et al., 2006) and these genetic influences on peer group deviance increase across adolescence, accounting for only 30% of the variance in peer group deviance at 8–11 years of age, but steadily rising to account for 50% of the variance in peer group deviance from age 15 onward (Kendler et al., 2007). Genetic influences on “environmental” factors is likely one of the pathways by which genetic influences increase in importance across adolescence, as adolescents increasingly gain autonomy to shape their own worlds.
