xyy-chromosome defense

XYY-chromosome defense. Criminal law. A defense, usu. asserted as the basis for an insanity plea, whereby a male defendant argues that his criminal behavior is due to the genetic abnormality of having an extra Y chro-mosome, which causes him to have uncontrollable aggressive impulses. • Most courts have rejected this defense because its scientific foundations […]

Criminal law. A defense, usu. asserted as the basis for an insanity plea, whereby a male defendant argues that his criminal behavior is due to the genetic abnormality of having an extra Y chro-mosome, which causes him to have uncontrollable aggressive impulses. • Most courts have rejected this defense because its scientific foundations are uncertain.