An Evolutionary Perspective on Sexual Assault; plus recommendations for improving the effectiveness of sexual assault prevention programs with exercises to reduce the possibility of hostile/reactive aggression in high-risk men

An Evolutionary Perspective on Sexual Assault and Implications for Interventions. Mark Huppin, Neil M. Malamuth, Daniel Linz. Handbook of Sexual Assault and Sexual Assault Prevention pp 17-44, October 19 2019. https://link.springer.com/chapter/10.1007/978-3-030-23645-8_2

Abstract: Interventions to reduce sexual assault at institutions of higher learning often have not been shown to be effective and may actually do more harm than good with men at high risk for sexual aggression. We argue that to design more effective interventions, it is essential to incorporate knowledge about the risk factors increasing the likelihood of sexual aggression. The single best predictor of risk for being a perpetrator is being a male and the best predictor of being a victim is being a female. Understanding why this is so may be aided by an approach incorporating evolved psychological mechanisms calibrated by cultural, social, and developmental factors. We consider hypotheses regarding evolved mechanisms for both males and females. We review evidence supporting the hypothesis of specialized mechanisms in women designed to avoid or limit the costs of forced sex. There is also some supportive evidence for the possibility that for males, evolved mechanisms may be calibrated by factors such as perceived negative experiences with women to increase the likelihood of committing sexual aggression. We illustrate such a mechanism by focusing on sexual arousal to forced sex, which may serve as an approach emotion facilitating sexual aggression. In using both evolutionary and proximate analyses, we address not only the question of what characteristics predict male sexual aggression but also why are these the risk factors. Finally, we outline a series of recommendations for improving the effectiveness of sexual assault prevention programs, including exercises to reduce the possibility of hostile/reactive aggression in high-risk men.

Keywords: Sexual assault Sexual aggression Evolution Psychology Rape Adaptations Specialized mechanisms Hostile masculinity Psychological reactance Prevention programs Interventions


Sexual Aggression in Other Species

Also relevant to EP theories of sexual coercion is evidence of sexual aggression in other species. In fact, physical force, harassment, and other intimidation to obtain sex have been reported in many species. Based on a review of the literature on forced copulation among nonhumans, Lalumière, Harris, Quinsey, and Rice (2005) identified specific characteristics in those species that exhibit sexual coercion. Across all nonhuman species, forced copulation is always perpetrated by males on females. Despite the tendency of females in some species to be assertive in the mating process, the authors could not find one instance of a female forcing sex on a male. Further, males are more likely to target fertile than infertile females for forced copulation, and forced copulation does occasionally result in insemination, fertilization, and offspring. Also, males of most species tend not to engage solely in coercive sexual behaviors. Most males that engage in forced copulation at other times court females. Finally, Lalumière et al. (2005) recognized the role of individual differences in sexual coercion. Certain males are more likely than others to engage in forced copulation, and some males are more successful at sexual coercion than others. They conclude that sexual coercion (particularly in the form of forced copulation) "is a tactic used by some males under some conditions to increase reproduction" (p. 59).

A particularly interesting species to consider is the orangutan, one of the few nonhuman primates for which sexual coercion is common. There is evidence for two distinct classes of orangutan males: large or flanged males, who develop secondary sexual characteristics such as cheek pads and large throat sacs, and small or unflanged males. Both types are sexually mature, though the onset of sexual maturity can be highly variable. Large males typically weigh over 80 kg in the wild, about twice the size of the small males (Knott, 2009; Knott & Kahlenberg, 2007). Although both types resort to forced copulations, they are significantly more often used strategically by small males, who force more than 80% of their total copulations at some orangutan sites (although only about half or fewer of their copulations are forced at other sites, suggesting the role of environmental contingencies such as population density and sex ratio in the incidence of sexual aggression) (Knott, 2009; Knott & Kahlenberg, 2007).

In a study of chimpanzees, our closest genetic relatives, sexual coercion as long-term intimidation was positively associated with paternity, particularly among high-ranking males, suggesting that it is a strategy used to increase reproductive fitness (Feldman et al., 2014). Sexually coercive tactics toward a female also provide delayed mating benefits in chacma baboons, due in part to the fact that male aggression preferentially targets fertile females (Baniel, Cowlishaw, & Huchard, 2017). As the authors explain, .By repeatedly attacking females in the weeks preceding ovulation, males appear to increase their chances of monopolizing sexual access to females around ovulation, which in turn increases their probability of successful reproduction. (p. 2166). The authors were able to rule out several competing hypotheses for male sexual violence perpetration (e.g., cycling females are more aggressive than noncycling females; females prefer to mate with aggressive males).


Summary and Recommendations for Sexual Assault Interventions

7. Interventions that are effective for women and most men may show .boomerang. effects with high-risk males. In order to effectively change the behavior of these men, prevention programs should consider introducing exercises likely to reduce the possibility of hostile/reactive aggression.

To the extent that recurrent ancestral conditions existed such that for some men sexual coercion contributed to overall reproductive success, the psychological architecture of men today who have experienced relevant developmental adversity may be calibrated in a way that helps motivate sexual assault to obtain sex from an unwilling partner. What.s more, there is a real possibility that many current sexual assault prevention programs may be interacting with the psychological makeup of these high-risk males to create boomerang reactance effects.

Many high-risk men may experience current programs on college campuses as both manipulative and provocative. To these young men such intervention efforts are directed at supporting more positive treatment for a group, undergraduate women, who seem to them to already "get all the breaks." These programs may therefore threaten these men.s self-concept and perceived freedoms. Especially if they see intervention messages as condescending and therefore insulting, they may respond in anger and with greater support for aggression. From an EP perspective, if we conceive of sexual strategies within the framework of a coevolutionary "arms race" between men and women, it is unsurprising that messages suggesting or dictating to sexually coercive young men how they should behave toward women will be ineffective, especially if these men feel that they have something to lose from this (Mealey, 2003).

The evaluations of current sexual assault programs generally have not examined the impact on sexually aggressive men. If currently effective programs work at all for such men, they may do so only indirectly. For example, bystander intervention programs may reduce the ability of high-risk men to carry out an assault by changing the responses of the low-risk, less violent people around them. Any net positive effect, however, is most likely due to a change in the environment in which some assaults occur rather than by having an effect on the high-risk male himself.

An extensive critical review of the scientific literature on prevention efforts on U.S. college campuses was recently published by Newlands and O'Donohue (2016). In order to facilitate improvement, the authors made some recommendations for developing more rigorous research programs. Among them is the idea that attending to "differences between participants can elucidate what factors influence or moderate treatment success or failure" (p. 10). In light of growing evidence of boomerang reactance effects described below, whereby interventions may result in an increased probability that relatively high-risk males will endorse sexually violent attitudes and be willing to behave more aggressively after the intervention compared to before, attending specifically to men's individual risk profiles appears highly important.

For many years, based on repeated findings in various areas (e.g., alcohol consumption, home energy use), reviewers of public health campaigns have called attention to the possibility of adverse boomerang effects. As some reviewers have noted, "An obvious implication is that boomerang effects should be taken into account as one of the potential costs of launching a mass communication campaign" (Ringold, 2012, p. 27). Most relevant to the current focus, boomerang effects have been well documented in areas of interventions designed to change antisocial behaviors, including sexual and nonsexual violence (see, e.g., Byrne & Hart, 2016; Wilson, Linz, Donnerstein, & Stipp, 1992). For example, an analysis of the consequences of a domestic violence campaign that included multiple television and newspaper advertisements demonstrated such unintended effects (Keller, Wilkinson, & Otjen, 2010). One of the stated goals of the program was to change the attitudes and behaviors of potential perpetrators. Only women.s perception of the severity of domestic violence (e.g., "Domestic violence is a serious issue that requires government or police involvement") increased after the campaign, however. Perceptions of the severity of domestic violence actually substantially decreased for the men in the study.

Cardaba, Brinol, Brandle, and Ruiz-SanRoman (2016) conducted research on the effects of anti-violence campaigns in different countries with different age populations. In one study, they found that individuals with relatively higher scores in trait aggressiveness showed a boomerang effect of anti-violence messages since they actually increased their favorability of attitudes toward violence. In contrast, the anti-violence campaigns were effective for those with relatively lower trait aggressiveness. In a second study, the intervention campaign again worked for the low trait-aggressive individuals but not for the high trait-aggressive participants. Another study reporting boomerang effects in the area of violence was conducted by Rivera, Santos, Brandle, and Cardaba (2016). The authors randomly assigned a large number of Italian students to participate in an intervention campaign designed to reduce participants. acceptance of violent video games. Participants were classified according to their relational lifestyle, consisting of four groups: e.g., "communicative" adolescents were more highly engaged in "civic values duties! in their communities than other groups; "meta-reflexive" adolescents had the lowest probability of seeking parents. support; whereas .fractured. adolescents had a higher probability of taking drugs than other groups and of engaging in other relatively delinquent behaviors. The group with a "fractured" or problematic lifestyle showed a boomerang effect, increasing their intent to play violent video games, whereas the other participants reduced their desire as a result of the intervention or there was a null effect. This finding is noteworthy as it is consistent with the idea in EP that sexually aggressive men can be "generalists" or "specialists," with implications for how different men might be expected to respond differently to the same sexual assault prevention program based on group membership.

We could not find any studies that specifically examined the impact of any elaborate interventions on high-risk males. The studies we did find all involved some form of intervention of less than one or two hours. One of these was a systematic experiment using a well-validated laboratory analogue of sexual aggression. In a community sample of American men, Bosson, Parrott, Swan, Kuchynka, and Schramm (2015) found that men low in sexism showed less aggressive tendencies following exposure to messages emphasizing norms of gender equality (e.g., most men approve of "men doing half of the housework and childcare"). Conversely, men high in hostile sexist attitudes showed a boomerang effect of increased sexually aggressive tendencies.

In a study of undergraduate men, Stephens and George (2009) examined the impact of a rape prevention intervention on low- vs. high-risk men. Risk level was determined by whether individuals had reported previously engaging in sexually aggressive behavior. The researchers found that men in general showed reductions in rape myth acceptance and an increase in victim empathy at a 5-week follow-up. Subgroup analyses, however, indicated that low-risk men were responsible for these findings. High-risk men showed no reliable attitudinal changes from the intervention. More alarmingly, high-risk men in the intervention group were more likely at follow- up to report higher sexually coercive behaviors than were high-risk men in a control group, although the sample size was small.

In another study that presented men a bystander sexual violence prevention program consisting of multifaceted training and skills development, outcome measures of rape myth acceptance and sexually coercive behavioral intentions were reduced among low-risk men (Elias-Lambert & Black, 2016). The program was relatively ineffective with high-risk men, however, leading the authors to conclude that .high-risk males may require a different type of prevention program that can help change the stubborn attitudes and habits they have developed. (p. 3229).

In order to avoid the possibility of boomerang effects, prevention programs should consider introducing exercises likely to reduce the perception of women as out-group threat. Using techniques such as self-affirmation and identity verification may be effective in this regard. These could be incorporated as part of a more comprehensive program for high-risk males, prior to the introduction of specific educational interventions. By moderating perceptions of out-group threat, these experiences can serve to mitigate hostile reactance.

According to self-affirmation theory (Steele, 1988), individuals have a fundamental motivation to protect their personal image. Self-threatening information is likely to elicit defensive responses such as rejecting the information, presenting counterarguments, or expressing resistance to change in order to restore one.s self-integrity. When one.s self-integrity is supported via self-affirmation, however, one can more carefully consider views and information that otherwise would be too threatening to accept (Cohen & Sherman, 2014; Sherman, 2013).

Self-affirmations have been found to increase positive other-directed feelings (Crocker, Niiya, & Mischkowski, 2008). They have been shown to have physiological bases for their desired effects by buffering neuroendocrine and psychological stress responses (Creswell et al., 2005) and by activating relevant brain-reward systems (Dutcher et al., 2016). By reducing defensive information processing, self-affirmations can increase the effectiveness of educational campaigns (Cohen, Aronson, & Steele, 2000) via how campaigns are framed and embodied. To our knowledge, existing efforts to educate undergraduate students, and high-risk men specifically, about sexual violence prevention have not included these self-image maintenance processes. Because of this, these programs are more likely to have unintended, counterproductive consequences.

Similarly, research on identity verification has found that when the set of meanings in a situation does not match people.s internal standards, and someone else does not confirm or verify their identities, they can experience negative emotional arousal such as hostility (Cast & Burke, 2002). If the lack of verification persists, an individual ultimately may resort to tactics of physical or sexual aggression over others in order to reassert control over the environment (Stets, 1992).

Many current sexual assault prevention programs contain admonishments that may create hostility and lead to a diminished sense of control for high-risk men, such that a resort to sexual violence to compensate for this loss is possible. Identity-verification can serve to reduce or eliminate such backlash responses by creating feelings of positive arousal including high self-esteem and mastery (Burke & Stets, 1999; Cast & Burke, 2002), setting the stage, e.g., for approach behaviors to programmatic information such as increased perspective taking. Research from identity theory suggests that verifying high-risk men in areas affiliated with their aggressive personality, such as masculinity, athletics, or a personal identity related to the degree to which they see themselves as more or less controlling may be most likely to create the conditions for attitudinal and behavioral change (Stets & Burke, 1994), as part of a comprehensive educational program for change.