Advances in the understanding of same-sex and opposite-sex sexual harassment

Sexual harassment has traditionally been studied as men's harassment of women. This has led to a lack of knowledge about same sex harassment, and women harassing peers. This has also downplayed the inherent sexual nature of sexual harassment acts. While keeping in mind that sexual harassment is undesirable and causes distress, one needs to consider that many acts that are perceived as unwanted may not primarily be motivated by a wish to derogate but rather by an interest in soliciting short-term sex. In the current study we examined both perpetrators as well as victims of harassment, and specified both sex of perpetrator and target (a total of eight sex constellations). We reproduced the previously found association between unrestricted sociosexuality and sexual harassment in a representative sample of 1326 high school students (57% women). In all regression models sociosexuality outcompeted traditional measures such as porn exposure, rape stereotypes and hostile sexism. Based on the original work we divided the harassment acts into two groups of tactics: sexual solicitation and competitor derogation. Men were particularly subject to derogatory tactics from other men, while women were particularly subject to solicitation from opposite sex peers. Sexual harassment may be understood better from a human sexual strategies perspective, including competitor derogation and mate solicitation. As such, sociosexual orientation predicts both same sex derogation and opposite sex solicitation. The current results highlight the importance of considering the sex of both perpetrator and target. This advanced understanding of the inherently sexual nature of sexual harassment needs to inform future prevention studies. Unrestricted sociosexuality predicts sexual harassment in all constellations better than traditional social science models.     

Facial correlates of sociosexuality

Previous studies have documented variation in sexual behaviour between individuals leading to the notion of ‘restricted’ individuals (i.e., people who prefer long-term relationships) and ‘unrestricted’ individuals (i.e., people who are open to short-term relationships). This distinction is often referred to as sociosexual orientation. Observers have been previously found to distinguish sociosexuality from video footage of individuals, although the specific cues used have not been identified. Here we assessed the ability of observers to judge sexual strategy based specifically on cues in both facial composites and real faces. We also assessed how observers' perceptions of the masculinity/femininity and attractiveness of faces relate to the sociosexual orientation of the pictured individuals. Observers were generally able to identify restricted vs. unrestricted individuals from cues in both composites and real faces. Unrestricted sociosexuality was generally associated with greater attractiveness in female composites and real female faces and greater masculinity in male composites. Although male observers did not generally associate sociosexuality with male attractiveness, female observers generally preferred more restricted males' faces (i.e., those with relatively strong preferences for long-term relationships). Collectively, our results support previous findings that androgenisation in men is related to less restricted sexual behaviour and suggest that women are averse to unrestricted men.     

Disgust sensitivity predicts sociosexuality across cultures

Restricted sociosexuality has been linked to sexual disgust, suggesting that decreasing sexual behavior may be a pathogen avoidance technique. Using the behavioral immune system framework, which posits that humans experience disgust after exposure to pathogen cues, we replicate and expand on previous studies by analyzing the influence of three domains of disgust (sexual, moral, pathogen) on psychological (desire and attitude) and behavioral domains of sociosexuality (SOI) in four diverse samples: American university students (n = 155), Salvadoran community members (n = 98), a global online sample (n = 359), and a four-country online sample (US, India, Italy, and Brazil; n = 822) collected during the SARS-CoV-2 pandemic. In contrast with previous studies, we account for shared variance in sexual, pathogen, and moral disgust by entering all three in a multiple regression to predict composite SOI. In both large samples, sexual disgust and pathogen disgust had opposing effects on composite SOI; that is, higher sexual disgust and lower pathogen disgust were associated with more restricted composite SOI. Additionally, we constructed a multi-group structural equation model (SEM) to determine the impact of each domain of disgust on each domain of SOI across all our samples simultaneously, while controlling for age and sex. Within this model we also assessed how the psychological domains of SOI – attitude and desire – mediate the relationship between disgust and sociosexual behavior. Pathogen disgust positively predicted SOI attitude and desire, but not behavior, consistently across all groups. SOI behavior was only predicted by pathogen disgust when mediated by SOI attitude, again across all groups, suggesting that behavior seems to be driven largely by the psychological facets of SOI. We discuss these findings in light of the behavioral immune system and the bet-hedging hypothesis, which make opposing predictions on the relationship between infection risk and sexual behavior.     

The evolutionary psychology of sexual harassment in organizations

We explore the value of theory developed in the field of evolutionary psychology for predicting and explaining patterns of sociosexual interaction between men and women in the workplace. In particular, we focus on assessing the value of this theoretical framework for increasing our understanding of the behavioral phenomenon of sexual harassment in organizations. To do this, we develop hypotheses based on a consideration of the evolved psychological mechanisms which have been proposed by evolutionary psychologists to underly human sexual behavior. We then review the existing literature on sociosexual behavior and sexual harassment within the workplace as a preliminary test of predictions concerning the expected profile, reaction, and motivation of recipients and initiators of sexual advances in the workplace. We also analyze the expected effect of novel aspects of the organizational environment on overt sexual behavior. This theory predicts, for example, that most sexual harassment will be initiated by men, and that young, single women will be the most frequent victims. This theory also predicts that women will generally experience a more negative reaction than men to sexual advances in the workplace, but that this emotional response will be mediated by other factors such as the profile of the initiator. The available data generally confirm these and other related predictions. Moreover, these results are quite consistent with other studies of the evolutionary psychology of human sexuality. We discuss the implications for theory in this area, and suggest some potentially fruitful avenues for original empirical research on human sexual behavior, inside or outside the workplace.     

Sociosexuality,testosterone, and life history status: prospective associations and longitudinal changes among men in Cebu,Philippines

Sociosexuality is defined as an individual's interest in uncommitted sexual activity and can be measured in terms of both psychological orientations and behavioral expression. In socio-ecological contexts in which adults monogamously partner and cooperate to raise children, individuals with unrestricted sociosexuality are likely to prioritize mating/competition over committed partnering and parenting. Given the importance of mother-father cooperation in the evolutionary past, humans may have the capacity to facultatively and opportunistically downregulate sociosexuality to focus on priorities related to invested partnering and parenting. To date, no prior studies have used longitudinal data to track within-individuals changes in sociosexuality as it relates to such life history transitions. Given the lack of prior longitudinal research in this area, it is likewise unknown what physiological mechanisms might mediate within-individual changes in sociosexuality through time but testosterone is a plausible candidate. To explore these questions, we drew on a large, long-running study of Filipino men (n?=?288), who were single non-fathers at 25.9?years of age and were followed up 4–5?years later. We found that men with more unrestricted sociosexuality at baseline were more likely to experience relationship dissolution by follow-up, consistent with past work. Compared to men who remained single non-fathers at follow-up, men who became married residential fathers showed shifts towards more restricted global sociosexuality as well as sociosexual behavior. Relative to their own baseline values, married residential fathers also had more restricted sociosexuality in all domains at follow-up. They were the only group for whom this was found. We found theoretically-consistent but modest support for positive correlations between men's testosterone and their sociosexuality, but no evidence that the two change in tandem together through time. Our results suggest that some amount of between-individual differences in sociosexuality are not stable and can facultatively shift alongside other aspects of male reproductive effort.     

Reproductive interests and dimensions of political ideology

Issues that relate to sex and reproduction are among the most hotly debated topics in modern politics, and a number of recent studies have sought to identify the relationship between sexual views and political ideology. In general, studies report that liberals have more permissive sexual views. Combining insights from political science about the dimensionality of political ideology with insights from evolutionary psychology about individual differences in sexual strategies, I argue and demonstrates that the association between permissive sexual views and liberalism masks a more complex set of associations. Individuals with an unrestricted sociosexual orientation are indeed more liberal on issues about authorities (as measured by Right‐Wing Authoritarianism) but are, at the same time, more conservative when it comes to views about dominance and hierarchies (as measured by Social Dominance Orientation). These findings enlighten recent debates about the nature of self‐interest in the formation of political views.     

Could sex be maintained through harmful males?

All else being equal, parthenogenetic females should produce as many surviving daughters as sexual couples produce daughters plus sons. Hence the resources spent on producing sons are a cost of sex and parthenogenetic females economize on sons. It has recently been shown that a small competitive advantage of sexual individuals can recoup this large reproductive disadvantage, while the adaptation behind the competitive advantage might differ from case to case. One hypothesis that has not yet been considered as a potential competitive advantage is that males could differentially harm parthenogenetic females, for example, through harassment, toxic seminal fluids, or infanticide. Harmful male functions result from the selection for males that maximise their fitness at the expense of females in the context of sexual conflict. Unless parthenogenetic lineages can maintain their resistance against harmful male functions, a competitive advantage for sex should be a by-product benefit of sexual conflict.
Mutations that make males harm parthenogenetic females worse than sexual ones, however, can be seen as evolutionary spite. The spiteful trait is not the production of costly sons, but the production of males that discriminate against parthenogenetic females. Spiteful behaviour can be positively selected, if it acts against negatively related victims. Sexual and parthenogenetic individuals within a population should usually be negatively related, because the genomes of the sexual individuals are bound together by recombination while those of parthenogenetic individuals will be identical except for divergence through mutation.
Some unusual cases of parthenogenesis are discussed in the light of this new hypothesis and an experimental approach for testing it is suggested.     

Sexual conflict and the tragedy of the commons

It is widely understood that the costs and benefits of mating can affect the fecundity and survival of individuals. Sexual conflict may have profound consequences for populations as a result of the negative effects it causes males and females to have on one another's fitness. Here we present a model describing the evolution of sexual conflict, in which males inflict a direct cost on female fitness. We show that these costs can drive the entire population to extinction. To males, females are an essential but finite resource over which they have to compete. Population extinction owing to sexual conflict can therefore be seen as an evolutionary tragedy of the commons. Our model shows that a positive feedback between harassment and the operational sex ratio is responsible for the demise of females and, thus, for population extinction. We further show that the evolution of female resistance to counter harassment can prevent a tragedy of the commons. Our findings not only demonstrate that sexual conflict can drive a population to extinction but also highlight how simple mechanisms, such as harassment costs to males and females and the coevolution between harassment and resistance, can help avert a tragedy of the commons caused by sexual conflict.     

Facial shape provides a valid cue to sociosexuality in men but not women

Existing work suggests that observers' perceptions of sociosexuality from strangers' faces are positively associated with individuals' self-reported sociosexuality. However it is not clear what cues observers use to form these judgements. Over two studies we examined whether sociosexuality is reflected in faces, which cues contain information about sociosexuality, and whether observers' perceptions of sociosexuality from faces are positively associated with individuals' self-reported sociosexuality. In Study One, Geometric Morphometric Modelling (GMM) analysis of 103 Caucasian participants revealed that self-reported sociosexuality was predicted by facial morphology in male but not female faces. In Study Two, 65 Caucasian participants judged the sociosexuality of opposite sex faces (faces from Study One) at zero acquaintance. Perceived sociosexuality predicted self-reported sociosexuality for men, but not women. Participants were also presented with composites of faces of individuals with more unrestricted sociosexuality paired with composites of faces of individuals with more restricted sociosexuality and asked to indicate which was more unrestricted. Participants selected the more unrestricted sociosexuality male, but not female, facial composites at rates significantly above chance. GMM analyses also found that facial morphology statistically significantly predicted perceived sociosexuality in women's and, to a greater extent, in men's faces. Finally, facial shape mediated the relationship between perceived sociosexuality and self-reported sociosexuality in men's but not women's faces. Our results suggest that facial shape acts as a valid cue to sociosexuality in men's but not women's faces.     

Giving or Receiving Something for Sex: A Cross-Sectional Study of Transactional Sex among Ugandan University Students

Objective

This study sought to determine the prevalence of transactional sex among university students in Uganda and to assess the possible relationship between transactional sex and sexual coercion, physical violence, mental health, and alcohol use.

Methods

In 2010, 1954 undergraduate students at a Ugandan university responded to a self-administered questionnaire that assessed mental health, substance use, physical violence and sexual behaviors including sexual coercion and transactional sex. The prevalence of transactional sex was assessed and logistic regression analysis was performed to measure the associations between various risk factors and reporting transactional sex.

Results

Approximately 25% of the study sample reported having taken part in transactional sex, with more women reporting having accepted money, gifts or some compensation for sex, while more men reporting having paid, given a gift or otherwise compensated for sex. Sexual coercion in men and women was significantly associated with having accepted money, gifts or some compensation for sex. Men who were victims of physical violence in the last 12 months had higher probability of having accepted money, gifts or some compensation for sex than other men. Women who were victims of sexual coercion reported greater likelihood of having paid, given a gift or otherwise compensated for sex. Respondents who had been victims of physical violence in last 12 months, engaged in heavy episodic drinking and had poor mental health status were more likely to have paid, given a gift or otherwise compensated for sex.

Conclusions

University students in Uganda are at high risk of transactional sex. Young men and women may be equally vulnerable to the risks and consequences of transactional sex and should be included in program initiatives to prevent transactional sex. The role of sexual coercion, physical violence, mental health, and alcohol use should be considered when designing interventions for countering transactional sex.     

Why are some people more jealous than others? Genetic and environmental factors

Research on romantic jealousy has traditionally focused on sex differences. We investigated why individuals vary in romantic jealousy, even within the sexes, using a genetically informed design of ~7700 Finnish twins and their siblings. First, we estimated genetic, shared environmental and nonshared environmental influences on jealousy, Second, we examined relations between jealousy and several variables that have been hypothesized to relate to jealousy because they increase the risk (e.g., mate-value discrepancy) or costs (e.g., restricted sociosexuality) of infidelity. Jealousy was 29% heritable, and non-shared environmental influences explained the remaining variance. The magnitude and sources of genetic influences did not differ between the sexes. Jealousy was associated with: having a lower mate value relative to one's partner; having less trust in one's current partner; having been cheated by a previous or current partner; and having more restricted sociosexual attitude and desire. Within monozygotic twin pairs, the twin with more restricted sociosexual desire and less trust in their partner than his or her co-twin experienced significantly more jealousy, showing that these associations were not merely due to the same genes or family environment giving rise to both sociosexual desire or trust and jealousy. The association between sociosexual attitude and jealousy was predominantly explained by genetic factors (74%), whereas all other associations with jealousy were mostly influenced by nonshared environmental (non-familial) factors (estimates >71%). Overall, our findings provide some of the most robust support to date on the importance of variables predicted by mate-guarding accounts to explain why people vary in jealousy.     

Social implications of the battle of the sexes: sexual harassment disrupts female sociality and social recognition

Across sexually reproducing species, males and females are in conflict over the control of reproduction. At the heart of this conflict in a number of taxa is male harassment of females for mating opportunities and female strategies to avoid this harassment. One neglected consequence that may result from sexual harassment is the disruption of important social associations. Here, we experimentally manipulate the degree of sexual harassment that wild female guppies (Poecilia reticulata) experience by establishing replicated, semi-natural pools with different population sex ratios. We quantify the effects of sexual harassment on female social structure and the development of social recognition among females. When exposed to sexual harassment, we found that females had more disparate social networks with limited repeated interactions when compared to females that did not experience male harassment. Furthermore, females that did not experience harassment developed social recognition with familiar individuals over an 8-day period, whereas females that experienced harassment did not, an effect we suggest is due to disruption of association patterns. These results show that social network structure and social recognition can be affected by sexual harassment, an effect that will be relevant across taxonomic groups and that we predict will have fitness consequences for females.     

A model of sexual selection and female use of refuge in a coercive mating system

In many non-monogamous systems, males invest less in progeny than do females. This leaves males with higher potential rates of reproduction, and a likelihood of sexual conflict, including, in some systems, coercive matings. If coercive matings are costly, the best female strategy may be to avoid male interaction. We present a model that demonstrates female movement in response to male harassment as a mechanism to lower the costs associated with male coercion, and the effect that female movement has on selection in males for male harassment. We found that, when females can move from a habitat patch to a refuge to which males do not have access, there may be a selection for either high, or low harassment male phenotype, or both, depending on the relationship between the harassment level of male types in the population and a threshold level of male harassment. This threshold harassment level depends on the relative number of males and females in the population, and the relative resource values of the habitat; the threshold increases as the sex ratio favours females, and decreases with the value of the refuge patch or total population. Our model predicts that selection will favour the harassment level that lies closest to this threshold level of harassment, and differing harassment levels will coexist within the population only if they lie on the opposite sides of the threshold harassment. Our model is consistent with empirical results suggesting that an intermediate harassment level provides maximum reproductive fitness to males when females are mobile.     

Variation in sociosexuality across natural menstrual cycles: Associations with ovarian hormones and cycle phase

The psychological construct of sociosexuality—one's sexual openness or propensity to engage in uncommitted sexual relationships—has been broadly examined within numerous cultures and mating contexts. Although there is some evidence suggesting that components of sociosexuality, namely behavior, desire and attitude, change within-person, relatively little research has investigated potential sources of such variation. The aim of our study was to explore if the individual components of sociosexuality change across the menstrual cycle, either as a function of cycle phase or ovarian hormones. One hundred and two naturally cycling women, both single and in a committed relationships, completed questions from the the SOI-R (Sociosexuality Revised) questionnaire three times during a menstrual cycle, scheduled to coincide with their early follicular, peri-ovulatory, and luteal phases. Women provided saliva samples and performed luteinizing hormone tests to distinguish between ovulatory and anovulatory cycles. Women reported slightly more openness to uncommitted sexual relationships during the peri-ovulatory session, but significant differences were restricted only to women who exhibited the luteinizing hormone surge. Ovarian hormone concentrations within cycles significantly predicted SOI Attitude and Desire scores, with estradiol positively related, and progesterone negatively related to openness to uncommitted sexuality. These effects were generally modest in size. The results of this study suggest that sociosexuality can vary within short periods of time, such as a single menstrual cycle.     

Multiple partners are associated with higher testosterone in North American men and women

Previous research has shown that being partnered is associated with lower testosterone (T) in men and women. To address how multiple partners may be associated with T, we examined 47 men and 48 women who were single, monoamorously partnered (partnered), polyamorous (having multiple committed relationships), or in a polyamorous lifestyle but not currently multipartnered. Men who were partnered had lower T than all other men, and polyamorous men had higher T than single men. Polyamorous women had higher T than all other women. Measures of sociosexual orientation (SOI) and sexual desire differed in women by relationship type, but not in men. Findings are interpreted in light of 'competitive' and 'bond-maintenance' relationship orientations and statuses.     

Cross-generational effects of sexual harassment on female fitness in the guppy

Sexual harassment is a common outcome of sexual conflict over mating rate. A large number of studies have identified several direct costs to females of sexual harassment including energy expenditure and reduced foraging ability. However, the fitness consequences of sexual harassment for descendants have rarely been investigated. Here, we manipulated the level of sexual harassment and mating rate in two groups of female guppies, Poecilia reticulata, a live-bearing fish in which sexual conflict over mating rate is particularly pronounced. Each female was allowed to interact with three males for one day (low sexual harassment, LSH) or for eight days (high sexual harassment, HSH) during each breeding cycle throughout their life. Female lifetime fecundity did not differ between the groups, but we found a strong effect on offspring fitness. HSH females produced (1) daughters with smaller bodies and (2) sons with shorter gonopodia, which were less attractive to females and less successful in coercive matings than their LSH counterparts. Although these results may be influenced by the indirect effects of sex ratio differences between treatments, they suggest that sexual harassment and elevated mating rate can have negative cross-generational fitness effects and more profound evolutionary consequences than currently thought.     

Sociosexuality moderates the association between testosterone and relationship status in men and women

Single individuals typically have higher testosterone compared to those who are partnered, suggesting that individual differences in testosterone are associated with mating effort, or people's motivation to find a sexual partner. However, there is less consistent evidence for links between testosterone and sociosexuality, or people's orientation toward uncommitted sexual activity. Based on Penke and Asendorpf's (2008) conceptualization, we propose that a more nuanced measure of sociosexuality may reveal more robust associations with testosterone. In the current study, we assessed relations between three components of sociosexuality—desire, behavior, and attitudes—and endogenous testosterone levels in men and women. We found that partnered status was indeed associated with lower testosterone in both men and women, but only among those who reported more restricted sociosexuality. Partnered men who reported greater desire for uncommitted sexual activity had testosterone levels that were comparable to those of single men; partnered women who reported more frequent uncommitted sexual behavior had testosterone levels that were comparable to those of single women. These findings provide new evidence that people's orientations toward sexual relationships, in combination with their relationship status, are associated with individual differences in testosterone. The current results are also among the first to demonstrate sociosexuality-testosterone associations in both men and women, and they reveal that the nature of these associations varies by gender. Together, these findings highlight the utility of a multifaceted conceptualization of sociosexuality and the implications of this conceptualization for neuroendocrine processes.     

Sexual harassment of a king penguin by an Antarctic fur seal

Males of gregarious pinnipeds are often aggressive to conspecifics and sexual coercion of females is commonplace. Males of some pinniped species have been known to attempt interspecific copulation, occasionally being successful in producing hybrid offspring. The most extreme case of interspecific sexual coercion reported concerned species from different families. We report a case of interspecific sexual harassment bridging the rank of vertebrate class.     

Fitness Costs of Sexual Harassment–The Price of Persuasion

Females are often subjected to unwanted mating advances from males. Such advances can be costly to both parties. The short‐term costs of harassment to females have been widely explored in the literature; however, few studies have measured the direct fitness costs. Moreover, male costs are seldom considered. Conventional wisdom would lead us to hypothesise that sexual harassment is costly; thus, when males and females are housed together, harassment should reduce foraging, growth and reproductive output and may disrupt social interactions. This study quantified harassment costs in both sexes by observing behavioural responses and long‐term effects of unsolicited mating in a controlled setting. Sexually mature guppies were subjected to two housing treatments: equal sex ratios or single‐sex groups. The effects of male harassment on males and females were assessed by measuring behaviour, growth rate and the number of offspring produced over a period of 6 mo. Contrary to our expectations, our results indicated no significant differences in foraging and growth rates between mixed‐ and single‐sex shoals for either sex. Moreover, there was no significant difference in fry production between mixed‐ and all‐female shoals. Large males showed higher mortality when housed with females. Both sexes showed a reduction in shoaling when in mixed‐sex groups. Thus, there appear to be few direct costs of harassment for females in natural, mixed‐sex shoals, but males appear to bear significant harassment costs. The study provides insights into reproductive behaviour and life‐history traits.     

Male coercion and the costs of promiscuous mating for female chimpanzees

For reasons that are not yet clear, male aggression against females occurs frequently among primates with promiscuous mating systems. Here, we test the sexual coercion hypothesis that male aggression functions to constrain female mate choice. We use 10 years of behavioural and endocrine data from a community of wild chimpanzees (Pan troglodytes schweinfurthii) to show that sexual coercion is the probable primary function of male aggression against females. Specifically, we show that male aggression is targeted towards the most fecund females, is associated with high male mating success and is costly for the victims. Such aggression can be viewed as a counter-strategy to female attempts at paternity confusion, and a cost of multi-male mating.