The subjects completed instruments measuring paternal involvement, low empathy/high emotional instability, marital dissatisfaction, severe parental abuse in childhood, rejection/neglect by parent, child sexual victimization, and youth sex offenses. The findings confirmed the biosocial hypothesis, in that fathers actively involved in the care of a daughter appeared to be at lower risk for incest. Neither childhood abuse nor low empathy explained the connection between low caretaking and incest. Neither did emotional instability, marital dissatisfaction, or negative prenatal attitudes toward the child. There was no evidence of a critical period in the first three years of the child's life; fathers who gave little care to their child in the first year could still be at reduced risk if they were high in caretaking at a later time. 2 tables, 2 figures, and 33 references