Genetic effects on anger control and their interaction with alcohol intoxication: a self-report study

Individual differences in anger control are important to consider when trying to understand intoxicated aggression (Parrott and Giancola, 2004). We explored, first, genetic and environmental effects on anger control both in self-reported sober and alcohol intoxicated states, and whether the same genetic and environmental effects influence it in both these states, and second, a possible interaction between genetic effects and alcohol in the control of anger. In the population based sample (N=8964) of Finnish twins (18-33 years) and their siblings (18 years or older), genetic effects on anger control were found both for the self-reported sober (27% for men, 34% for women) and alcohol intoxicated states (29% for men, 37% for women), with high genetic correlations (from .77 to .85) between these states. Genetic effects (26% for men, 29% for women) were also found for the difference in anger control between the self-reported sober and alcohol intoxicated states, suggesting the effect of alcohol on anger control depends on the genotype of the individual.