Fowler, Baker & Dawes (2007) recently showed in two independent studies of twins that voter turnout has very high heritability. Here we investigate two specific genes that may contribute to this heritability via their impact on neurochemical processes that influence social behavior. Using data from the National Longitudinal Study of Adolescent Health, we show that a polymorphism of the MAOA gene significantly increases the likelihood of voting. We also find evidence of a gene-environment interaction between religious attendance and a polymorphism of the 5HTT gene that significantly increases voter turnout. These are the first results to ever link specific genes to political behavior.
The authors find that the MAOA gene increases the likelihood of voting by 5 percentage points. The 5HTT gene increases the likelihood of voting by 10 points in interaction with an environmental factor, religious attendance. I note that only to preempt fears of genetic determinism, not to detract from this interesting finding.