Irrational decisions: attending to numbers rather than ratios

A discussion is presented of the issues raised by Skeem and Zuckerman regarding whether psychopathic personality can be regarded as a unitary construct, the validity of the distinction between psychopathic personality and anti-social personality, the adequacy of the Psychopathic Deviate scale of the MMPI as a measure of psychopathic personality, the validity of results of the community studies of the prevalence of anti-social personality disorder, and the evolutionary theory of race differences.