The sample was divided into three groups: sibling offenders, child molesters (non-family child victims), and nonchild offenders. Data relating to family environment, socialization and sexual victimization were studied resulting in a profile of sibling incest offenders as those coming from the most dysfunctional families, with high rates of physical, sexual, and drug/alcohol abuse. Significant findings indicated deficient socialization and predicted the choice of victim by the offender. Low rates of prior sexual experience with peers by offenders at the time of the crime provide some support for the blockage theory of child molesting. 23 tables, 17 references. (Author abstract modified)