Genotype-environment correlation in the era of DNA.

Robert Plomin

doi:10.1007/s10519-014-9673-7

Abstract

One of John Loehlin’s many contributions to the field of behavioral genetics involves gene-environment (GE) correlation. The empirical base for GE correlation was research showing that environmental measures are nearly as heritable as behavioral measures and that genetic factors mediate correlations between environment and behavior. Attempts to identify genes responsible for these phenomena will come up against the ‘missing heritability’ problem that plagues DNA research on complex traits throughout the life sciences. However, DNA can also be used for quantitative genetic analyses of unrelated individuals (Genome-wide Complex Trait Analysis, GCTA) to investigate genetic influence on environmental measures and their behavioral correlates. A novel feature of GCTA is that it enables genetic analysis of family-level environments (e.g., parental socioeconomic status) and school-level environments (e.g., teaching quality) that cannot be investigated using within-family designs such as the twin method. An important implication of GE correlation is its shift from a passive model of the environment imposed on individuals to an active model in which individuals actively create their own experiences in part on the basis of their genetic propensities.

Highlights

John Loehlin’s influence on my career involves geneenvironment (GE) correlations of a personal as well as scientific kind
For GE correlation reasons that involve appetite more than aptitude, this course, and especially John Loehlin’s contribution, made me realize that behavioral genetics was the field for me, even though none of the other 40 students in the core course were enticed to behavioral genetics
I was so impressed with the Texas Adoption Study that John Loehlin and Joseph Horn had established while I was a graduate student at Texas (Horn et al 1979; Horn and Loehlin 2010; Loehlin et al 1981) that I decided, with John DeFries, to conduct a study of newborn adoptees in Colorado, which became the Colorado Adoption Project (Plomin and DeFries 1985)

Summary

Introduction

John Loehlin’s influence on my career involves geneenvironment (GE) correlations of a personal as well as scientific kind. More than 30 years later, his work continues to advance these topics of nonshared environment (Loehlin 2007; Loehlin and Martin 2011b); differential heritability for personality traits (Loehlin 2012); and multivariate genetic issues especially in relation to a general factor of personality (Loehlin 2011; Loehlin and Horn 2012; Loehlin and Martin 2011a, 2013) He has written about GE correlation and other aspects of the interplay between genes and environment (Loehlin 2010a, b). I was so impressed with the Texas Adoption Study that John Loehlin and Joseph Horn had established while I was a graduate student at Texas (Horn et al 1979; Horn and Loehlin 2010; Loehlin et al 1981) that I decided, with John DeFries, to conduct a study of newborn adoptees in Colorado, which became the Colorado Adoption Project (Plomin and DeFries 1985) Another example of John Loehlin’s impact on my scientific career is my interest in GE correlation, which was sparked by John Loehlin while I was at Texas. He wrote the last sentence of the paper: ‘‘And one day, perhaps, we may yet get to the ribosomes’’ (p. 321)

GE correlation

Findings

GE correlation and an active model of experience