Related Experiment Video
Updated: Oct 2, 2026

Moderate Prenatal Alcohol Exposure and Quantification of Social Behavior in Adult Rats
Published on: December 14, 2014
Gene-environment interaction effects on behavioral variation and risk of complex disorders: the example of alcoholism
Andrew C Heath1, Alexandre A Todorov, Elliot C Nelson
1Missouri Alcoholism Research Center, Department of Psychiatry, Washington University School of Medicine, St Louis 63108, USA. andrew@matlock.wustl.edu
Abstract:
There have been few replicated examples of genotype x environment interaction effects on behavioral variation or risk of psychiatric disorder. We review some of the factors that have made detection of genotype x environment interaction effects difficult, and show how genotype x shared environment interaction (GxSE) effects are commonly confounded with genetic parameters in data from twin pairs reared together. Historic data on twin pairs reared apart can in principle be used to estimate such GxSE effects, but have rarely been used for this purpose. We illustrate this using previously published data from the Swedish Adoption Twin Study of Aging (SATSA), which suggest that GxSE effects could account for as much as 25% of the total variance in risk of becoming a regular smoker. Since few separated twin pairs will be available for study in the future, we also consider methods for modifying variance components linkage analysis to allow for environmental interactions with linked loci.
Related Concept Videos
Human Genetics
The complex relationship between genetics and psychology is observable through common biological components such...
Behavioral Genetics and Its Designs
The primary methodologies used in behavior genetics include family studies, twin studies, and adoption studies, each providing unique...
Gene-Environment Interactions
Causes of Social Behavior III: Biological and Environmental Influences
Background and Environment Affect Phenotype
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
Heritability

