Genotype-environment interaction and correlation in the analysis of human behavior.

TLDR

Two issues that complicate behavioral genetic analyses are the interaction and correlation between genetic and environmental influences. The study examines how genotype‑environment interaction and correlation affect twin and adoption behavioral genetic analyses and proposes new tests using adoption data. The authors propose new tests of genotype‑environment interaction and correlation based on adoption data. The analysis indicates that genotype‑environment interaction may bias twin study estimates but not adoption studies, while genotype‑environment correlation can affect both twin and adoption estimates, with direction depending on the sign of the correlation.

Abstract

Two issues that complicate behavioral genetic analyses are the interaction and correlation between genetic and environmental influences. In this report, the effects of genotype-envi ronment interaction and correlation on behavioral genetic studies (twin and adoption studies) are examined. The analysis suggests that genotype-environment interaction may bias twin study estimates of genetic and environmental influence, but need not affect adoption studies. On the other hand, genotype-environment correlation may affect both twin and adoption study estimates of genetic and environmental influence, the direction of the effect depending on the sign of the correlation. Finally, new tests of genotypeenvironment interaction and correlation, using adoption data, are proposed.