which acts to reinforce organizational skills. Because these types of environmental experiences are able to get “under the skin” of individuals, “DNA sequences are not the simple, unchanging causal mechanisms depicted in typical biological personality models,” and “environments can and do affect physiological systems, even one as basic as DNA” (Roberts & Jackson, 2008, p. 1532). Therefore, based on this perspective, one would expect significant, direct environmental influences on personality development. Environmental stability would be predicted to be low in early ages but to increase substantially throughout the entire lifespan, with some decline in old age when social environments change considerably. Genetic effects might be predicted to be fairly unstable, as the sociogenomic model emphasizes that environments are capable of altering gene expression across the lifespan. Increases in phenotypic stability would largely be explained by increasingly stable contributions from the environment with genetic contributions remaining largely constant across the lifespan.
