Study participants ranged in age from 12 to 18 years and included 21 sex offenders and 17 oppositional defiant adolescents in a residential treatment center. The group of 21 sex offenders had 56 known victims and had perpetrated at least one touching offense. Oppositional defiant adolescents consisted of youth who were being treated for such behavioral problems as fighting, vandalism, stealing, cruelty to animals, running away, and suicidal gestures. The High School Personality Questionnaire measured factorially independent personality dimensions. Results suggested that sex offenders had difficulty with impulsiveness and that sex offenders differed from the oppositional group on factor scores usually indicative of juvenile delinquency. Sex offenders tended to be more intelligent than delinquents, despite having significantly more school problems than the oppositional group. Sex offenders often seemed normal, with fewer behavioral problems than juvenile delinquents. An appendix contains data on the relationship between sex offenders and victims. 25 references, 1 table, and 2 figures