Five groups of male subjects participated in the study: 22 incestuous child molesters, 21 extrafamilial child molesters, 33 rapists, 27 nonsex offenders, and 26 laypersons with no known criminal history of child molestation or rape. The Marlow-Crowne Social Desirability Scale controlled for socially desirable response sets. The Fear of Negative Evaluation Scale measured sensitivity to negative evaluations by others and avoidance of criticism. The Interpersonal Reactivity Index measured four components of empathy, and the Cognition Scale assessed the extent of cognitive distortion in child molesters. Results of the study provide partial support for the hypothesis that child molesters have cognitions different from control groups. Incestuous and extrafamilial child molesters had a greater fear of negative evaluation than rapists, and extrafamilial molesters had a higher level of cognitive distortion than all other groups; however, molesters' reported empathy levels were similar to those obtained from comparison groups. Child molesters were distinguished from rapists in having a greater fear of negative evaluation. The affective and cognitive empathy variables failed to show significant differences between child molesters and the other groups. As predicted, extrafamilial child molesters were more likely than all other comparison group to endorse beliefs about the appropriateness of sexual contact with children. Study results suggest that child molesters and rapists should be separated for research and treatment, because they engage in criminal sexual behaviors for different reasons. 2 tables and 20 references