Sex Chromosomes, Crime, and Psychosis

Abstract

Questioning the belief that XYY men are predisposed to violent behavior, the authors compared XYY men in penal institutions with men with the Klinefelter syndrome (XXY). They found little difference between their behavior and criminal records. They conclude that XYY men have been stigmatized falsely and that their involvement in crimes and antisocial behavior may not be significantly different from the normal individual's.