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University of Pennsylvania Law Review



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biological deficiency, defense, crime, genetics


This Comment presents three major arguments concerning biological deficiency defenses, using, respectively, a critique of biosocial science research, a statistical model of biological and sociological data, and an examination of theories and philosophies on causation and behavior. First, this Comment argues that there should be no defense to mitigate criminal responsibility except in the less that one percent of cases eligible for the insanity defense. Second, this Comment argues that social science research has not successfully demonstrated sufficiently strong links between biological factors and criminal behavior to warrant major consideration in determining criminal responsibility. Third, this Comment demonstrates that no strong evidence supports either a strictly free will or a strictly deterministic philosophy in the criminal law regarding either the causes of crime or the determinants of criminal responsibility. Ultimately, the criminal justice system must confront the significance of the mounting evidence concerning the biological bases of behavior, weigh its importance, evaluate its strengths and weaknesses, and recommend a policy for its use. The direction of that policy will depend upon our notions of human nature, our assumptions of causality, and, undoubtedly, the politics and potentially broad applicability of the biological deficiency argument.

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Criminal Law Commons