Document Type


Publication Title

American Journal of Criminal Law



Publication Date

Fall 1994


Death penalty, retardation, Penry, Texas, Nexus


In Penry v. Lynaugh, the United States Supreme Court held that the Texas death penalty statute was applied unconstitutionally because the trial court gave no instructions allowing the jury to “consider and give effect to” the defendant's mitigating evidence of organic brain damage, moderate retardation, and disadvantaged background. The Court considered these mitigating factors relevant because of society's steadfast belief in the lesser culpability of defendants whose criminal acts are due to a disadvantaged background, or to emotional and mental disorders. The jury must have full consideration of such evidence in order to give its “reasoned moral response” to the defendant's character and crime. Yet Penry and its progeny have provided no adequate guidance on what jury instructions and mitigating factors, apart from those presented in Penry, would be appropriate in other cases. As a result, the Texas Court of Criminal Appeals has applied such restrictive evidentiary standards to Penry claims that nearly all are denied apart from those few that proffer the “same” or “similar” evidence found in Penry. This Article empirically challenges the legal doctrine underlying Penry and its progeny. First, it shows that there is no empirical support for the Texas court's constricted interpretation of the kinds of mitigating evidence that can provide Penry relief under Article 37.071, the former Texas death penalty statute at issue in Penry. Next, it contends that Penry's whole concept of mitigation and aggravation rests upon false assumptions concerning the correlates of crime and future dangerousness. These conclusions are based primarily upon the results of the “Biosocial Study,” one of this country's largest studies of biological and environmental correlates of crime. The Biosocial Study analyzed numerous variables predicting crime within a group of nearly five hundred males who resided in Philadelphia from the time of their birth until their twenty-second birthday. Although there have been many longitudinal studies of crime and behavioral disorders, no one has been able to examine so intensively a large sample of individuals both before and after the start of their criminal careers.