There was a moderately strong and significant relationship between testosterone and adult deviance. This relationship was mediated largely by the influence of testosterone on social integration as well as on prior involvement in juvenile delinquency. Testosterone level also moderated the relationship of social integration to adult deviance. The restraining influence of social integration was less necessary for those with lower testosterone levels. Prior delinquency interacted with social integration similarly and accounted for much of the moderating effect of social integration. The findings provide support for the conclusions that testosterone is one of a constellation of factors which contributes to a general latent propensity toward deviance, and the influence of testosterone on adult deviance is closely tied to social factors. 11 notes, 3 figures, 3 tables, and 40 references