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Young sex offenders: A comparison with a control group of non-sex offenders

The body of literature on adolescent sexual aggression is very limited. In fact, a recent literature review(2) identified only five studies that have explored this area through statistical comparisons with non-sexually aggressive control groups. This scarcity of controlled scientific studies is striking considering the magnitude of the problem -most adult sex offenders begin their deviant behaviour during adolescence.(3)

Adolescent males commit approximately 20% of the sexual assaults against adolescents and adults, and between 30% and 50% of such assaults against children.(4) What is often considered "exploration" or dismissed as "boys will be boys" is often, in fact, criminal behaviour with traumatic consequences for its victims.(5) Further, a young sexually aggressive male who does not receive treatment can be expected to commit an average of 380 sexual crimes in his lifetime.(6)

Not only is there disappointingly little controlled research on young sex offenders, there is also little developed theory in this area. Only recently have elementary theoretical models and classification systems been proposed, and they are only now beginning to receive some empirical support.

This article provides some of this support by empirically testing a recently proposed theory of adolescent sexual aggression.

Becker and Kaplan's risk factors

Becker and Kaplan(7) have proposed a theory of adolescent sexual aggression that might be better described as a framework for proposed risk factors rather than a theory. They argue that certain risk factors predispose an adolescent to engage in aggressive sexual behaviour, such as:

  • having experienced physical and sexual abuse;
  • depression;
  • poor academic performance;
  • a history of non-sexual antisocial behaviour;
  • poor family relationships; social isolation (such as an inability to establish and maintain close relationships with same-age peers);
  • a lack of social and assertion skills;
  • a lack of impulse and anger control;
  • inadequate sex education; and
  • having witnessed family violence.

Existing research results provide some support for Becker and Kaplan's model, but the research is characterized by lack of control groups and small sample sizes (fewer than 20 young sex offenders). This study attempts to overcome these limitations by comparing 52 young sex offenders with 800 young non-sex offenders.


The 852 members of the sample were consecutive admissions (over seven years) to the young offender unit of detention centre. The offenders had been incarcerated because they had been convicted of a criminal offence(s) or because they were awaiting trial for an offence(s) allegedly committed when they were 16 or 17 years old.

Each offender was interviewed individually and underwent a battery of risk and needs tests.

The tests included the Young Offender Level of Service Inventory,(8) the Criminal Sentiments Scale,(9) the Pride in Delinquency Scale,(10) the Neutralization Scale(11) and the Trauma Symptom Checklist.(12)

As mentioned, 52 (6.1%) of the 852 subjects had been convicted of a sexual offence. The average age of the sex offenders was 17.3 years and all but one were male. On the other hand, the average age of the 800 young non-sex offenders was 17.2 and 722 (91%) were male.

All of the sex offenders had been convicted of "hands-on" offences (such as fondling, sexual assault or attempted sexual assault), but the age of the victim, the relationship between the offender and the victim, and the level of violence involved in the offence were neither recorded nor available.

Table 1

A Comparison of Young Sex Offenders and Non-sex Offenders
Young sex
Young non-sex
difference (t-test)
Were sexually abused
Depression score
Failed a grade in school
Two or more prior convictions
Poor classroom behaviour
Suspended or expelled from school
Poor relations with family members
Were physically abused
Poor relations with school peers
Peers outside their age range
* Score on the Trauma Symptoms Checklist
(*=p<.05, **=p<.01, ***=p<.0001
Supporting the factors

The young sex offenders were compared with the non-sex offenders on 10 variables relevant to Becker and Kaplan's model (see Table 1) - although relevant data were not available to test all the variables. The results support the Becker and Kaplan assertions that young sex offenders are characterized by sexual abuse, depression, poor academic performance and non-sexual antisocial behaviour.

Sex offenders were more likely to report that they themselves had been sexually abused. This is consistent with the notion that deviant sexual behaviour may be learned from models, attitudes and information experienced during developing years. In particular, it has been argued that deviant sexual behaviour is learned through one's own victimization or through exposure to unhealthy or unusual attitudes within the family.(13)

Also consistent with Becker and Kaplan's model is the finding that young sex offenders had higher Trauma Symptom Checklist depression scores than young non-sex offenders. This reinforces the findings of a recent study revealing that young sex offenders with personal histories of abuse scored higher than a control group of non-offending adolescents on the Beck Depression Inventory.(14)

The finding that more sex offenders than non-sex offenders failed a grade is also consistent with the argument that young sex offenders are characterized by poor academic performance.

Finally, the finding that the young sex offenders were as likely as the non-sex offenders to have had two or more prior convictions, poor classroom behaviour and to have been suspended or expelled from school is compatible with Becker and Kaplan's assertion that the behaviour of young sex offenders is antisocial in non-sexual areas.

Unsupportive results

The study's results failed to support four of Becker and Kaplan's risk factors. Young sex offenders were no more likely than the control group to have been physically abused, to have had poor relations with family members, to be socially isolated or to associate with peers outside their age range.

The next step

One limitation of this study is that data relevant to a number of Becker and Kaplan's risk factors were not available (such as assertion skills, anger/impulse controls, sex education and witnessing family violence). The study also could not examine subgroups of young sex offenders (such as those who assault children, family members, or same-age peers) because the specific types of sexual offences committed were not available.

A third limitation is the difficulty in determining whether young sex offenders differed from non-sex offenders before they were incarcerated. incarceration should not affect historical variables (such as having failed a grade), but it could influence variables such as level of depression. Other inmates tend to view sex offenders negatively. As a result, sex offenders often have more difficulty adjusting to incarceration and might, therefore, be more likely to be depressed.

This controlled study of young sex offenders is only the sixth of its type to be reported. The magnitude of the problem justifies far more empirical research. Further, models such as the one proposed by Becker and Kaplan are useful, but there is a real need for theories of adolescent sexual aggression to guide research on, and identification and treatment of, this serious social problem.

(1)Please address correspondence to Ian Shields, Department of Psychology, Ottawa-Carleton Detention Centre, 2244 Innes Road, Ottawa, Ontario K1B 4C4. Opinions expressed in this article are those of the authors and are not necessarily those of the Ministry of the Solicitor General and Correctional Services of Ontario.
(2)J. V. Becker, C. D. Harris and B. D. Sales, "Juveniles Who Commit Sexual Offenses: A Critical Review of Research," Sexual Aggression: Issues in Etiology, Assessment, and Treatment, G. C. N. Hall, R. Hirschman, I. R. Graham and M. S. Zaragoza, eds. (Washington: Taylor and Francis, 1993).
(3)G. G. Abel, M. M. Mittelman and J. V. Becker, "Sex Offenders: Results of Assessment and Recommendations for Treatment," Clinical Criminology: The Assessment and Treatment of Criminal Behavior, M. H. Ben-Aron, S.J. Hucker and C. D. Webster, eds. (Toronto: M & M Graphics, 1985).
(4)H. E. Barbaree, S. M. Hudson and M. C. Seto, "Sexual Assault in Society: The Role of the Juvenile Offender," The Juvenile Sex Offender, H. F. Barbaree, W. L. Marshall and S. M. Hudson, eds. (New York: The Guilford Press, 1993).
(5)Barbaree, Hudson and Seto, "Sexual Assault in Society: The Role of the Juvenile Offender."
(6)G. G. Abel, I. v. Becker, I. Cunningham-Rathner, I. Rouleau, M. Kaplan and I. Reich, Treatment Manual: The Treatment of Child Molesters (Tuscaloosa: Emory University Clinic, Department of Psychiatry, 1984).
(7) J.V. Becker and M. S. Kaplan, "The Assessment of Adolescent Sexual Offenders," Advances in Behavioral Assessment of Children and Families, 4 (1988): 97-118.
(8)I. W. Shields, "The Use of the Young Offender-Level of Service Inventory with Adolescents," The IARCA Journal on Community Corrections, 5 (1993): 10-26. See also I. W. Shields and D. I. Simourd, "Predicting Predatory Behavior in a Population of Incarcerated Young Offenders," Criminal Justice and Behavior, 21 (1991): 180-194.
(9)D. A. Andrews, "Notes on a Battery of Paper-and-Pencil Instruments: Part I - Assessments of Attitudes and Personality in Corrections," Unpublished manuscript (Department of Psychology, Carleton University, 1985). See also D. A. Andrews, J.S. Wormith and I. J Kiessling, "Self-reported Criminal Propensity and Criminal Behavior: Threats to the validity of Assessments and Personality," Programs Branch User Report (Ottawa: Solicitor General of Canada, 1985).
(10)I. W. Shields and G. C. Whitehall, "The Pride in Delinquency Scale." Paper presented to the Annual Correctional Psychologists' Winter Conference (Eastern Region), Ottawa, Ontario, 1991.
(11)I. W. Shields and G. C. Whitehall, "Neutralization and Delinquency Among Teenagers," Criminal Justice and Behavior, 21(1994): 223-235.
(12)M. Runtz, "The Trauma Symptom Checklist (TSC-33): Early Data on a New Scale," Journal of Interpersonal Violence, 4 (1989) 151-163.
(13)G. Ryan, S. Lane, I. Davis and C. Isaac, "Juvenile Sex Offenders: Development and Correction," Child Abuse and Neglect, 11(1987): 385-395.
(14)J.V. Becker, M. S. Kaplan, C. E. Tenke and A. Tartaglini, "The Incidence of Depressive Symptomatology in Juvenile Sex Offenders with a History of Abuse," Child Abuse and Neglect, 15 (1991): 531-536.