Intergenerational incest aversion: self-reported sexual arousal and disgust to hypothetical sexual contact with family members

Vulnerability to Incest - Findings From a Comparative Single-Case Study of the Onset of Intrafamilial Child Sexual Abuse

Previous research about intrafamilial child sexual abuse was not able to identify specific risk factors that distinguish this unique subgroup from other sexual offending subgroups. In comparison to other groups of sexual offenders, men convicted of intrafamilial sexual child abuse (ICSA) are found to exhibit more similarities to non-offending fathers than extrafamilial sexual offenders. Consequently, the risk assessment of sexual recidivism among "incest offenders" lacks evidence-based evaluation criteria. Given the suggestion that family system factors should be included in research on the onset of ICSA, we employed the Vulnerability to Incest Model proposed by Trepper and Barrett (1989, https://doi.org/10.4324/9780203776605) in a qualitative single-case analysis. A comparative analysis of ten court evaluations of ICSA offenders revealed that all families in which ICSA has occurred demonstrated at least two vulnerability factors. The analyzed offenders exhibited comparable patterns of masculine sexual entitlement. The utility of this recently developed construct for sexual violence research is discussed and implications for further research proposed.

"Stigmatization and perceived dangerousness for intrafamilial child sexual abuse of fathers with a history of sexual offenses and paraphilic interests: Results from a survey of legal psychological experts"

BACKGROUND

Intrafamilial child sexual abuse (ICSA) is a puzzling phenomenon that is not well understood by researches. Nevertheless, psychologists are demanded to assess the risk for child maltreatment by family courts regarding male caregivers with a history of sex offenses and/or paraphilic interests.

OBJECTIVE

The aim of this study was to assess legal psychological experts' perspective on risk assessment in family court proceedings regarding ICSA, their opinions regarding the necessity of contact limitations between fathers/stepfathers who might impose a risk for ICSA, and experts' stigmatization of minor-attracted persons.

PARTICIPANTS AND SETTING

153 psychological experts working in family court proceedings were assessed via an online survey.

METHOD

Jahnke's Stigma Inventory was used as well as a questionnaire tapping into different contact limitations, the perception of child maltreatment risk, and parental capacity. Network analysis was conducted to multivariately investigate item intercorrelations.

RESULTS

Fathers/stepfathers with a diagnosed pedophilic disorder are being regarded as most dangerous, 71 % of the experts agreed with the necessity of a complete contact ban. Reduced parental capacity and increased risk for child maltreatment was observed with regard to sexual offending history and paraphilias.

CONCLUSIONS

Psychological experts in family court proceedings hardly discriminate between sexual offending and paraphilic interests which might be associated with stigmatizing attitudes and lack of experience. An increasing cooperation between family psychologists and experts of forensic risk assessment might reduce the risk of stigmatization and may contribute to more adequate risk assessments for ICSA thus aiding to prevent children from sexual victimization or misinformed risk management interventions.

Pandemic elevates sensitivity to moral disgust but not pathogen disgust

The behavioral immune system, with disgust as its motivational part, serves as the first line of defense in organisms' protection against pathogens. Laboratory studies indicate that disgust sensitivity adaptively adjusts to simulated environmental threat, but whether disgust levels similarly change in response to real-life threats, such as a pandemic, remains largely unknown. In a preregistered within-subject study, we tested whether the threat posed by the Covid-19 pandemic would lead to increased perceived disgust. The perception of threat was induced by testing during two phases of the Covid-19 pandemic (periods of high vs. low pathogen threat). We found heightened levels of moral disgust during a "wave" of the pandemic, but the effect was not observed in the domain of pathogen or sexual disgust. Moreover, the age of respondents and levels of trait anxiety were positively associated with pathogen and moral disgust, suggesting that variation in disgust sensitivity may be based chiefly on stable characteristics.

Meta-analytic evidence that animals rarely avoid inbreeding

Animals are usually expected to avoid mating with relatives (kin avoidance) as incestuous mating can lead to the expression of inbreeding depression. Yet, theoretical models predict that unbiased mating with regards to kinship should be common, and that under some conditions, the inclusive fitness benefits associated with inbreeding can even lead to a preference for mating with kin. This mismatch between empirical and theoretical expectations generates uncertainty as to the prevalence of inbreeding avoidance in animals. Here, we synthesized 677 effect sizes from 139 experimental studies of mate choice for kin versus non-kin in diploid animals, representing 40 years of research, using a meta-analytical approach. Our meta-analysis revealed little support for the widely held view that animals avoid mating with kin, despite clear evidence of publication bias. Instead, unbiased mating with regards to kinship appears widespread across animals and experimental conditions. The significance of a variety of moderators was explored using meta-regressions, revealing that the degree of relatedness and prior experience with kin explained some variation in the effect sizes. Yet, we found no difference in kin avoidance between males and females, choice and no-choice experiments, mated and virgin animals or between humans and animals. Our findings highlight the need to rethink the widely held view that inbreeding avoidance is a given in experimental studies.

An Examination of the Westermarck Hypothesis and the Role of Disgust in Incest Avoidance Among Fathers

From an evolutionary perspective, incestuous behavior is puzzling. The goal of this study was to assess the tenability of the Westermarck hypothesis (1891, 1921)-that people who live in close physical proximity with one another during childhood will develop a sexual indifference or aversion toward one another-and the mediating role of disgust as an incest avoidance mechanism in father-daughter relationships. A sample of fathers with daughters ( N = 632) from Canada and the United States were recruited by Qualtrics-a survey platform and project management company-to complete an online survey. The results from this study did not support the viability of the Westermarck hypothesis as a mechanism that facilitates incest avoidance for fathers. Physical proximity was not associated with incest propensity or disgust toward incest. Less disgust toward incest, however, was found to be associated with more incest propensity. These results indicate that physical proximity may not be a reliable kinship cue used by fathers to inform incest avoidance, but that disgust toward incest may still be a proximate mechanism that facilitates incest avoidance among fathers using kinship cues other than physical proximity.

Opposition to Inbreeding Between Close Kin Reflects Inclusive Fitness Costs

Due to the intense selection pressure against inbreeding, humans are expected to possess psychological adaptations that regulate mate choice and avoid inbreeding. From a gene's-eye perspective, there is little difference in the evolutionary costs between situations where an individual him/herself is participating in inbreeding and inbreeding among other close relatives. The difference is merely quantitative, as fitness can be compromised via both routes. The question is whether humans are sensitive to the direct as well as indirect costs of inbreeding. Using responses from a large population-based sample (27,364 responses from 2,353 participants), we found that human motivations to avoid inbreeding closely track the theoretical costs of inbreeding as predicted by inclusive fitness theory. Participants were asked to select in a forced choice paradigm, which of two acts of inbreeding with actual family members they would want to avoid most. We found that the estimated fitness costs explained 83.6% of participant choices. Importantly, fitness costs explained choices also when the self was not involved. We conclude that humans intuit the indirect fitness costs of mating decisions made by close family members and that psychological inbreeding avoidance mechanisms extend beyond self-regulation.