Retrospective data were entered anonymously by 1,521 adult women using computer-assisted self-interview. Nineteen were classified as victims of father-daughter incest, and 241 were classified as victims of sexual abuse by an adult other than their father before reaching 18 years of age. The remaining 1,261 served as controls. Incest victims were more likely than controls to endorse feeling damaged, psychologically injured, estranged from one or both parents, and shamed by others when they tried to open up about their experience. They had been eroticized early on by the incest experience, and it interfered with their adult sexuality. Incest victims experienced coitus earlier than controls and after reaching age 18 had more sex partners and were more likely to have casual sex outside their primary relationship and engage in sex for money than controls. They also had worse scores on scales measuring depression, sexual satisfaction, and communication about sex than controls.

Retrospective data were entered anonymously by 1,521 adult women using computer-assisted self interview. Forty were classified as victims of brother-sister incest, 19 were classified as victims of father-daughter incest, and 232 were classified as victims of sexual abuse by an adult other than their father before reaching 18 years of age. The other 1,230 served as controls. The victims of brother-sister incest had significantly more problematic outcomes than controls on many measures (e.g., more likely than the controls to endorse feeling like damaged goods, thinking that they had suffered psychological injury, and having undergone psychological treatment for childhood sexual abuse). However, victims of brother-sister incest also had significantly less problematic outcomes than victims of father-daughter incest on some measures (e.g., significantly less likely than the father-daughter incest victims to endorse feeling like damaged goods, thinking that they had suffered psychological injury, and having undergone psychological treatment for childhood sexual abuse).

Retrospective data were entered anonymously by 1,521 adult women using a computer-assisted self-interview. Thirty-one participants were victims of sister-sister incest, 40 were victims of brother-sister incest, 19 were victims of father-daughter incest, 8 were victims of sexual abuse by an adult female (including one mother), and 232 were victims of sexual abuse by an adult male other than their father before reaching 18 years of age. The rest (1,203) served as controls. The victims of sister-sister incest had significantly more problematic outcomes than controls on many measures as adults. Victims of sister-sister incest were more depressed and more likely than controls to be distant from the perpetrator-sister and to have traded sex for money, experienced an unplanned pregnancy, engaged in four different types of masturbation, and engaged in 13 different same-sex behaviors. Our findings were consistent with other reports of early eroticization and persistent hypereroticization of incest victims.

Retrospective data were entered anonymously by 1,178 adult men using computer-assisted self-interview. Twenty-seven were victims of sister-brother incest (SBI), 119 were victims of child sexual abuse by an adult female (CSA-AF) before 18 years of age, 1,032 were controls. SBI was often the first sexual experience for the victim. Our findings were consistent with other reports of early and persistent hyper-eroticization of incest victims. SBI increased the likelihood of engaging in behaviors as an adult consistent with a co-existing or primary male-male sexual orientation, and SBI and CSA-AF had deleterious impacts on adult men's sexual adjustment with their adult partners. Meiselman (1979, pp. 294-298) found eight cases of brother-sister incest described by sisters (BSI) and three cases sister-brother incest described by brothers (SBI) in her clinical sample. The three SBI victims Meiselman (1979) described had all been harmed by the SBI, but the victims described in two of the three cases also had been victims of incest perpetrated by other family members (the mother in one case and a brother in the other case). Over

Anonymous retrospective data were provided by 3,443 adult participants via computer-assisted self-interview. This was the first study focused on determinants of adult sexual orientation to adjust for the effects of same-sex sibling incest. Five measures of adult sexual orientations (ASOs) provided evidence consistent with the theory that ASOs result from early sex-specific romantic attachment, conditioning caused by early sexual experiences with partners, and other experiences, such as early masturbation using human images, acting synergistically with critical period learning, and sexual imprinting. Early same-sex crushes were the most powerful predictor of ASOs, and they also increased the likelihood of engaging in early samesex partnered and masturbation behaviors. Incestuous experiences with same-sex siblings affected the ASOs of the incest participants. And, lesbian, gay, and bisexual participants tended to have an earlier onset of puberty than heterosexual controls within sexes. However, statistical analyses showed that the incest and puberty effects were mathematically explained by the participant's early sexual experiences with partners and other experiences such as masturbation using human images. Early same-sex crushes were predicted by nuclear family variables implying that samesex crushes were more likely when the opposite-sex parent modeled an unsatisfactory heterosexual romantic partner.