Twin concordance for dishonorable discharge from the military: with a review of the genetics of antisocial behavior.

It has been hypothesized that there is a genetic component to antisocial behavior. To test this hypothesis, twin concordance for dishonorable discharge from the US military was examined among 15,924 twin pairs in the National Academy of Sciences-National Research Council (NAS-NRC) Twin Registry, all of whom served in the US military. Of 62 dizygotic (DZ) twin pairs, at least one of whom had received a dishonorable discharge, one pair (1.6%) was concordant for dishonorable discharge; of 47 monozygotic (MZ) twin pairs, seven (14.9%) were concordant for dishonorable discharge. Concordance rates for dishonorable discharge were significantly greater for MZ vDZ twin pairs. Concordances for dishonorable discharge were not confounded by co-diagnoses of alcoholism. The results are discussed in light of research findings suggesting a genetic component to antisocial behavior.