Is the Psychopath ‘morally insane’?

Very early accounts of Psychopathic Disorder explained the disorder in terms of a deficit within some form of moral faculty or structure (Pritchard, 1837; cited by Blackburn, British Journal of Psychiatry, 153, 505–512, 1988). However, such accounts fail to specify the nature of the faculty/structure or its role in the control of behaviour. Blair (Cognition, in press) has suggested that a mechanism for the control of aggression is a prerequisite for the development of morality. Specifically, he has suggested that this mechanism mediates the moral/conventional distinction for transgressions. Blair has suggested that psychopaths may lack this prerequisite, predicting that these subjects should fail to make the moral/conventional distinction for transgressions. The first goal of the present study was to replicate the findings of an earlier study (Blair, Cognition, in press) confirming this prediction. The second goal of the present study was to extend the earlier findings, to examine the influence of the proposed mechanism on the observed moral/conventional distinction for positive acts (Smetana, Bridgeman & Turiel, The Nature of Prosocial Development: Interdisciplinary Theories and Strategies. New York: Academic Press, 1983). The results closely replicated those of the earlier study for the transgression moral/conventional distinction; the psychopaths, in contrast to the controls, were failing to make this distinction. However, diagnosis did not predict performance for the positive act moral/conventional distinction; the psychopaths and the controls responded to these items similarly. The results are discussed with reference to theories of the development of the psychopath and theories of the development of morality.