Journal
PERSPECTIVES ON PSYCHOLOGICAL SCIENCE
Volume 18, Issue 2, Pages 416-427Publisher
SAGE PUBLICATIONS LTD
DOI: 10.1177/17456916221096122
Keywords
means; variances; environmental influences; genetic influences
Categories
Ask authors/readers for more resources
Twin and adoption studies focus on estimating genetic and environmental contributions to human traits by comparing individuals with different degrees of relatedness. However, these studies primarily consider variance and overlook the impact of mean effects. This exclusion may have masked important environmental influences and hindered a full understanding of the ubiquity and nature of gene-environment interplay in human outcomes.
Twin and adoption studies compare the similarities of people with differing degrees of relatedness to estimate genetic and environmental contributions to trait population variance. The analytic workhorse of these kinds of variance-focused designs is the intraclass correlation, which estimates similarity between pairs of individuals. Group means, by contrast, play no overt role in estimating genetic and environmental influences. Although this focus on variance has made very important contributions to understanding psychological characteristics, we contend that the exclusion of mean effects from behavioral genetic designs may have obscured key environmental influences and impeded full appreciation of the ubiquity and nature of gene-environment interplay in human outcomes. We provide empirical examples already in the literature and a theoretical framework for thinking through the incorporation of mean effects using largely forgotten, non-Mendelian theory regarding how genes influence human outcomes. We conclude that the field needs to develop models capable of fully incorporating mean effects into twin and adoption studies.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available