Some highly satisfied individuals were also more likely to have engaged in infidelity, suggesting a more complex relationship between relationship satisfaction and infidelity

Is Infidelity Predictable? Using Explainable Machine Learning to Identify the Most Important Predictors of Infidelity. Laura M. Vowels, Matthew J. Vowels & Kristen P. Mark. The Journal of Sex Research, Aug 25 2021. https://doi.org/10.1080/00224499.2021.1967846

Abstract: Infidelity can be a disruptive event in a romantic relationship with a devastating impact on both partners’ well-being. Thus, there are benefits to identifying factors that can explain or predict infidelity, but prior research has not utilized methods that would provide the relative importance of each predictor. We used a machine learning algorithm, random forest (a type of interpretable highly non-linear decision tree), to predict in-person and online infidelity across two studies (one individual and one dyadic, N = 1,295). We also used a game theoretic explanation technique, Shapley values, which allowed us to estimate the effect size of each predictor variable on infidelity. The present study showed that infidelity was somewhat predictable overall and interpersonal factors such as relationship satisfaction, love, desire, and relationship length were the most predictive of online and in person infidelity. The results suggest that addressing relationship difficulties early in the relationship may help prevent infidelity.

Discussion

Infidelity is relatively common, with up to half of those in relationships having engaged in infidelity (Mark & Haus, 2019; Mark et al., 2011; Thompson & O’Sullivan, 2016) with potentially devastating consequences for relationships causing distress (Thompson & O’Sullivan, 2016) and often divorce (Amato & Previti, 2004). Infidelity is likely to affect not only the couple members but also their children, extended family, and friends. It is important to identify potential risk factors for infidelity to target interventions that could prevent infidelity from occurring in the first place. The purpose of the present study was to identify potential factors associated with infidelity and to quantify and compare different factors to better understand which variables are the most strongly associated with infidelity.

A large body of literature has attempted to identify which factors contribute to infidelity. However, the studies have relied exclusively on linear models, which are often completely uninterpretable due to problems such as incorrect specification of the underlying causal structure, multicollinearity, unattainable parametric assumptions, and inability to examine complex associations (Breiman, 2001a; Lundberg et al., 2020; Yarkoni & Westfall, 2017). The present study is the first of its kind to examine predictors of infidelity using interpretable predictive models: random forests (Breiman, 2001b) with Shapley values (Lundberg et al., 2017, 2019). Based on our findings, the short answer to the question posed in the title, “is infidelity predictable?,” is somewhat. The effect sizes that consider the true and false positives and negatives of both classes ranged between small (.18) to large effect (.49) across analyses and samples suggesting that even though we were able to predict infidelity generally well above chance level, there are also other factors that we had not accounted for.

The Comparison of Predictors of Infidelity

While we examined the predictive accuracy of our models, our main aim was to compare a range of different factors in their ability to predict infidelity. A recent systematic review found that while demographics and individual characteristics are inconsistently associated with infidelity, relationship variables tend to be more consistent across studies (Haseli et al., 2019). We also found that relationship characteristics (relationship satisfaction, relationship length, dyadic desire, sexual satisfaction, romantic love, and some sexual activities within the relationship) were consistently in the top-10 most important predictors across different samples. These findings suggest that addressing relationship issues may buffer against the likelihood of one partner going out of the relationship to seek fulfillment. However, it is also important to note that while individuals who were more satisfied in their relationship were generally less likely to engage in infidelity, a subsample of highly satisfied individuals had engaged in infidelity in the past. This may either reflect the idea that infidelity does also occur in happy relationships (Perel, 2017) or perhaps couples have worked through the infidelity and by the time they responded to the survey were satisfied in their relationship (Olson et al., 2002).

Furthermore, because online infidelity has become more commonplace given the technological advances in recent years (Albright, 2008), we also examined predictors of online infidelity. Interestingly, one of the strongest predictors of a decreased likelihood of having engaged in infidelity online was never having had anal sex in the present relationship. This may reflect more restrictive attitudes toward sexuality overall. Indeed, attitudes toward sexuality were measured in Study 1 and ranked among the Top-10 predictors of online infidelity. However, the relationship was more complex, with the most liberal sexual attitudes predicting an increase in likelihood of having engaged in infidelity whereas more moderate and conservative attitudes predicted a decrease. These results are in line with other studies that have found that more permissive sexual attitudes have been associated with an increased likelihood of having engaged in infidelity (Fincham & May, 2017; Haseli et al., 2019; Martins et al., 2016). Higher relationship length and sexual desire also increased the likelihood of having engaged in online infidelity. However, sexual and relationship satisfaction were only among the top predictors in one of the two samples.

The results of the present study corroborate many of the existing studies, and akin to a recent systematic review (Haseli et al., 2019), show that the most robust predictors of infidelity lie within the relationship: individuals who are more satisfied and in love in their relationship are less likely to have engaged in infidelity. There are also a number of factors that have previously been associated with infidelity that were not among the most important predictors in the present study: education (Atkins et al., 2001; Martins et al., 2016; Treas & Giesen, 2000), relationship status (Amato & Previti, 2004; Fincham & May, 2017), and attachment (Fincham & May, 2017; Haseli et al., 2019; McDaniel et al., 2017). We only examined attachment in Study 1 and higher attachment avoidance did predict an increased likelihood of having engaged in infidelity in the total sample but was not among the top-10 predictors for men or women. Attachment anxiety was not predictive of past infidelity. Furthermore, many previous studies suggest that men are more likely to engage in sexual infidelity than women (Labrecque & Whisman, 2017; Petersen & Hyde, 2010). In the present study, being a man was only an important predictor of past online infidelity in one sample, supporting studies that have found that the gender gap in infidelity is decreasing (Allen et al., 2006; Fincham & May, 2017; Mark et al., 2011; Treas & Giesen, 2000).

There were also some inconsistencies in the findings across the two samples. In Study 1, hormonal contraceptives decreased the likelihood of men having engaged in online infidelity whereas in Study 2 the use of hormonal contraceptives increased the likelihood of both men and women having engaged in online infidelity. The use of hormonal contraceptives does not prevent sexually transmitted infections and therefore increases the likelihood of passing any potential infections from the infidelity partner to the primary partner. This may deter people from engaging in infidelity face-to-face and instead seek alternative partners online. It is not clear why in one sample hormonal contraceptives increased the likelihood of engaging in infidelity and in another decreased it and the role of contraceptives on infidelity warrants further investigation. Furthermore, because each individual predictor only predicted very little variance in the outcome, interpreting each individual variable becomes more difficult. When the signal is stronger (i.e., a variable predicts a larger amount of variance) the prediction also becomes more accurate.

Implications for Theory and Future Research

The present study examined predictors of infidelity from the ecological theory perspective (Bronfenbrenner, 1994). Specifically, we tested the ECSD model from a recent systematic review that suggested that both partners’ individual as well as couple’s factors predict infidelity. We found little evidence to suggest that partner variables predicted actor’s engagement in infidelity. In fact, in some analyses the predictive accuracy of the models decreased as a result of including partner variables in the models, suggesting that adding partner factors in the models may add noise that makes it more difficult for the model to make accurate predictions. Additionally, the present study suggested that relationship-related variables contributed the most to the prediction. However, it is important to caveat these findings in that we were essentially predicting infidelity in the past from the present variables. Therefore, it is possible that couples in which infidelity had occurred had worked through the infidelity and were now happier in their relationship than before.

In addition to relational variables, variables that tapped into people’s attitudes were also predictive of both in person and online infidelity. Overall, having less permissive attitudes toward sexuality suggested a decreased likelihood of having engaged in infidelity. Individuals with highly liberal attitudes were the most likely to have engaged in infidelity in the past. Certain sexual behaviors such as the use of sex toys, anal sex, and masturbation with a partner may also have acted as a proxy for attitudes in the present study. Indeed, previous studies have suggested that sexual attitudes and behaviors go hand in hand (Lefkowitz et al., 2014). The results of the present study suggested that individuals who had not engaged in traditionally more permissive sexual behaviors such as using sex toys or having anal sex were less likely to also have engaged in infidelity. Most other individual variables were not consistently among the Top-10 predictors of infidelity, which may explain why the results from previous studies (Haseli et al., 2019; Mark & Haus, 2019) have been inconsistent, especially when examining socio-demographic variables.

Finally, the purpose of the present study was to examine a range of variables in their ability to predict infidelity. Overall, each variable alone predicted little variance in infidelity. Therefore, the results do not suggest that there is one single, or a few, variables that are highly predictive of infidelity. Instead, a large number of variables together resulted in the algorithm’s overall ability to predict infidelity with a moderate to large effect size. Relationship variables together explained the largest amount of variance in the predictions. Relationship variables, however, are more likely to vary over time compared to certain individual characteristics (such as socio-demographic variables or attachment style). The prediction accuracy may have increased if the infidelity and relationship quality had been measured closer in time. Therefore, future research is needed to examine recent infidelity to more fully understand how relationship characteristics relate to infidelity. Additionally, because each variable contributed little to the overall prediction accuracy, using machine learning models with a large number of variables instead of focusing on single variables for predicting infidelity may be more fruitful in being able to predict who has or will engage in infidelity. This does not help target-specific factors but may be used to identify individuals or relationships who may be at a higher risk.

Strengths and Limitations

The present study adds to our understanding of the most important predictors for infidelity across two samples. We used a powerful interpretable machine learning technique that allowed us to produce reliable estimates of the effect sizes of each variable both for the mean effect as well as the spread of the individual effects (Lundberg et al., 2017, 2019). Using this method, we were also able to compare a large number of predictors simultaneously and estimate any non-linear associations and complex interactions. We also examined both in-person and online infidelity.

However, the study also had several limitations that should be considered. First, we used a single-item measure of in-person and online infidelity. We were thus unable to account for specific infidelity behaviors and did not examine emotional infidelity. Future research is needed to examine a wider range of infidelity behaviors to better understand whether the same predictors generalize across multiple forms of infidelity or whether these are predicted by different variables. The results from the present study suggest that these may be somewhat different given that the most important predictors of in-person and online infidelity also varied. Second, while we examined infidelity across two large samples with one sample including data from both members of the couple, the studies were all cross-sectional and it is not clear how recently the infidelity occurred. Therefore, some of the factors may have changed from when the infidelity occurred to when the participants completed the survey. This is a difficulty across most other studies on infidelity, but future research should examine infidelity over time or to conduct surveys on individuals who have just engaged in infidelity. Third, over 30% of the participants in Study 1 reported past infidelity. However, the number of participants who had engaged in infidelity in the dyadic sample was much lower. This made it more difficult for the algorithm to accurately predict infidelity which is reflected in lower precision and recall for the infidelity class compared to no infidelity. We used balanced random forests to mitigate this issue, but we still had less data available of people with past infidelity.

Furthermore, each variable contributed very little to the overall classification accuracy. Therefore, interpretation of the results may be less accurate than when individual variables have a clearer signal. Additionally, while random forests are a powerful tool that will take advantage of any correlations and interactions in the data, no matter how non-linear, it cannot be used to estimate causality. However, in the absence of a means to reliably estimate causality when examining factors relating to infidelity (after all we cannot create experiments in which we make people engage in infidelity), we believe that using a predictive model is perhaps the best option. Finally, we chose to use a random forest algorithm because of a moderate sample size. Random forests have been shown to perform well with their default settings without the need for hyperparameter tuning (Probst et al., 2019). Tuning hyperparameters requires a separate training set which would make the sample size in the test data smaller. However, there may be other algorithms that would perform better or similarly with hyperparameter tuning. Therefore, future research in larger samples could use different algorithms to compare the performance of different algorithms.

Sexuality, Sexual Behavior, and Relationships of Asexual Individuals: Differences Between Aromantic and Romantic Subtypes of Asexual Individuals

Carvalho, Ana C., and David L. Rodrigues. 2021. “Sexuality, Sexual Behavior, and Relationships of Asexual Individuals: Differences Between Aromantic and Romantic Orientation.” PsyArXiv. August 26. doi:10.31234/osf.io/f5hrb

Abstract: Asexuality is a complex construct with a considerable lack of research until recently. Building upon available findings, we examined the extent to which romantic orientation shapes individual and relationship experiences and expectations of asexual individuals. Specifically, our research focused on the distinction between romantic asexual individuals, who experience romantic attraction, and aromantic asexual individuals, who do not experience romantic attraction. A cross-sectional study with members of different asexual online communities (N = 447, 55.02% women; Mage = 24.77, SD = 7.21) aimed at examining how both groups differ in their identification with the asexuality construct as measured by the Asexuality Identification Scale (Yule et al., 2015), individual perspectives on sexuality, sexual behavior and relationships, concerns about commitment and sexual performance in a relationship, and attachment style. Results showed that aromantic asexual individuals identified more with asexuality, reported a more avoidant attachment style, and were more concerned with relationship commitment. In contrast, romantic asexual individuals reported less sex aversion, more sexual experiences (both past and current), and more sexual partners in the past. These individuals also indicated to have engaged in romantic relationships more frequently, desire to engage in romantic relationship in the future (either with or without sexual intimacy), and were more concerned with sexual performance. Overall, our findings contribute to the literature by highlighting the need to consider romantic orientation when examining asexuality and its interpersonal outcomes.

Topological measures for identifying and predicting the spread of complex contagions

Topological measures for identifying and predicting the spread of complex contagions. Douglas Guilbeault & Damon Centola. Nature Communications volume 12, Article number: 4430. Jul 20 2021. https://www.nature.com/articles/s41467-021-24704-6

Abstract: The standard measure of distance in social networks – average shortest path length – assumes a model of “simple” contagion, in which people only need exposure to influence from one peer to adopt the contagion. However, many social phenomena are “complex” contagions, for which people need exposure to multiple peers before they adopt. Here, we show that the classical measure of path length fails to define network connectedness and node centrality for complex contagions. Centrality measures and seeding strategies based on the classical definition of path length frequently misidentify the network features that are most effective for spreading complex contagions. To address these issues, we derive measures of complex path length and complex centrality, which significantly improve the capacity to identify the network structures and central individuals best suited for spreading complex contagions. We validate our theory using empirical data on the spread of a microfinance program in 43 rural Indian villages.

Discussion

Path length is one of the most important and influential measures of network structure. It underlies nearly every theory of social connectedness, social distance, and social influence within social networks. Here we show that the classical measure of simple path length, upon which most popular measures of node centrality depend, implicitly assumes the spreading dynamics of simple contagion. This assumption has resulted in several puzzling empirical findings in which individuals with putatively low centrality have been shown to be more influential for diffusion than individuals with high centrality (according to prominent measures of degree centrality, betweenness centrality, eigenvector centrality, k-core centrality, and percolation centrality). We derive new topological definitions of bridge width, path length, and centrality, which provide general topological measures for accurately estimating the network properties of connectedness, distance, and centrality for the spread of complex social contagions. We find that these measures offer significant theoretical improvements over existing measures of population-level network topology, and individual-level node centrality, for predicting the network properties that will increase the spread of complex social contagions.

Our findings offer several noteworthy departures from the dominant strategies for applying network theory to problems of social diffusion1,3,5,29,42,43,44,45,46,47. First, a common assumption among both theoretical and applied studies of network diffusion is that people with more connections are more influential5,21,22,29,30,42,43,44,45. Our findings disagree with the frequently asserted claim in this literature that degree centrality is an effective, if approximate, means of identifying the most influential individuals within a social network, regardless of context5,21,22,29,30,42,43,44,45. Second, a common assumption within organizational studies of social networks is that information brokers—i.e., people who participate in multiple distinct network communities that are largely disconnected—have outsized influence because they are the gatekeepers in the flow of contagions between communities46,47. This assumption has resulted in betweenness centrality becoming one of the most widely used measures of network influence within organizational theory1,27,29,42,43,46,47,48,49. By contrast, our findings indicate that network locations with low degree centrality and low betweenness centrality may nevertheless be the most influential locations in the population. We also find that individuals with the highest levels of degree centrality and betweenness centrality typically occupy ineffective network positions for initiating the spread of complex social contagions—including health behaviors8,9, linguistic conventions6,12,13, political memes14, social movements15,16, and complementary technologies6,10. We anticipate that an important direction for future work will be the exploration of new algorithms for computing the theoretical properties of complex path length and complex centrality, which may benefit from recent developments that improve the scalability of novel algorithmic techniques50. Another interesting direction for future research is the application of our topological measures for identifying specific network locations that can be used to efficiently stop the spread of an existing complex contagion from one part of a network to the entire population (akin to the problem of network “immunization” for simple contagions)6,51,52.

Beetles: Rapid evolution of sexual size dimorphism facilitated by Y-linked genetic variance

Rapid evolution of sexual size dimorphism facilitated by Y-linked genetic variance. Philipp Kaufmann, Matthew E. Wolak, Arild Husby & Elina Immonen. Nature Ecology & Evolution, Aug 19 2021. https://www.nature.com/articles/s41559-021-01530-z

Abstract: Sexual dimorphism is ubiquitous in nature but its evolution is puzzling given that the mostly shared genome constrains independent evolution in the sexes. Sex differences should result from asymmetries between the sexes in selection or genetic variation but studies investigating both simultaneously are lacking. Here, we combine a quantitative genetic analysis of body size variation, partitioned into autosomal and sex chromosome contributions and ten generations of experimental evolution to dissect the evolution of sexual body size dimorphism in seed beetles (Callosobruchus maculatus) subjected to sexually antagonistic or sex-limited selection. Female additive genetic variance (VA) was primarily linked to autosomes, exhibiting a strong intersexual genetic correlation with males (ram,f = 0.926), while X- and Y-linked genes further contributed to the male VA and X-linked genes contributed to female dominance variance. Consistent with these estimates, sexual body size dimorphism did not evolve in response to female-limited selection but evolved by 30–50% under male-limited and sexually antagonistic selection. Remarkably, Y-linked variance alone could change dimorphism by 30%, despite the C. maculatus Y chromosome being small and heterochromatic. Our results demonstrate how the potential for sexual dimorphism to evolve depends on both its underlying genetic basis and the nature of sex-specific selection.

The effects of alpha male removal on the social behavior of a group of olive baboons: Females seem to respond to male removal showing a more affiliative and tolerant behavior

The effects of alpha male removal on the social behavior of a group of olive baboons (Papio anubis). Ester Orient & Federico Guillén-Salazar. Journal of Applied Animal Welfare Science, Aug 26 2021. https://doi.org/10.1080/10888705.2021.1968401

Abstract: In captivity, the managers of primate populations have removed individuals from their groups for medical and social reasons, but there has been little documentation regarding the consequences of this extraction on the sociality of the remaining individuals. This study provides information about the social effect of the alpha male removal in a group of olive baboons (Papio anubis) maintained at the Station of Primatology of CNRS (France). Data on social behavior was collected before and after male removal and then compared. Moreover, this social information was used to calculate the individual dominance index and the group dominance ranking. Overall, our results indicate that females seem to respond to male removal showing a more affiliative and tolerant behavior. However, the results also highlight the different coping mechanisms of females with this new social context. Therefore, this information could be useful for managers of primate populations, allowing them to anticipate the response of captive groups when facing certain sociodemographic changes. In this regard, we recommended creating a detailed procedure before the removal of the individuals that considers the characteristics of the individuals.

KEYWORDS: Male removalolive baboon (Papio anubis)small groupssocial behavior

Discussion

The results presented here show how after male removal half of the dyads increased their grooming. Moreover, the females displayed a less aggressive behavior in general terms, especially to one of the most subordinate females, and a more tolerant behavior toward the most dominant female (decreas^Bing their retreats). The social scenario after male removal therefore seems to be close to a peaceful scenario, in which females try to increase the strength of their social bonds.

The increase of the affiliative interactions observed in females are consistent with the results obtained by Chowdhury and Swedell (2017) after the male’s death in a group of chacma baboons.

However, while these authors observed that all females invested more time in grooming, we only observed the increase of the interactions in half of them. In this sense, Chism & Rogers (2002) suggest that the removal of individuals may be disruptive to the relationships of certain animals, but not in others, as observed in this study. They also claim that interactions are established between real individuals, with their own characteristics (e.g., personality, experience) and not between theoretical categories of individuals.  Our results partially agree with the description made by authors such as Keddy-Hector and Raleigh (1992) or Lemasson et al. (2005) after alpha removals, because they state that the remaining individuals increase both affiliative and aggressive interactions but, in this study, females only increased their grooming exchanges. Moreover, our results are totally opposite to those obtained by other authors who pointed out that animals become more aggressive after the removal of the alpha individual (Lowland gorilla: Hoff et al., 1982; Rhesus macaques: Judge et al., 1995; Common marmosets: Lazaro-Perea et al., 2000). As indicated previously, our females showed a more tolerant behavior after male removal, decreasing their mutual aggressions and their avoidance of the more dominant female.

Changes in the dominance hierarchy are a common outcome of the modification of the socio-demographic composition of a group [Japanese macaques (Macaca fuscatta): (Kawai, 1960; Nakamichi et al., 1995); Rhesus macaques: (Bernstein, 1964); Vervet monkeys: (Guy & Curnoe, 2011)]. After a social and demographic change, the remaining individuals try to cope with this period of social instability by re-organizing their previous relationships (Colmenares & Gomendio, 1988), which may result in a change dominance ranking. In this work, there has been a slight change in the female dominance ranking after the male removal, particularly in regard to the two females located in lower positions. This change in the agonistic behavior of these females leads to a partial modification in the dominance ranking. Therefore, our results agree partially with the idea of a social reorganization after a period of instability, stated by Colmenares and Gomendio (1988).

As pointed out by Lemasson et al. (2005), the social status of individuals and the species are determining factors in the effects of the removal of an individual. We suggest that the changes observed in female behavior could be mainly due to the absence of the male, the most dominant individual in the group. These female behavioral adjustments are in line with statements from Packer and Pusey (1979) and Dunbar (2013) regarding the lack of female control over males in the baboon genus. The big size of male olive baboons, compared to their female counterpart, seems to provide the male with some degree of influence over female behavior and, consequently, over their sociality. Nevertheless, it should be noted, that despite the possibility that males exercise a certain influence over females, the alpha male of the study seemed to have established a “friendly relationship” with the most dominant female. Strum (1974) defined this type of relationship between males and females as a typical trait of the natural behavior of male baboons. Therefore, the identification of the typical traits of baboons’ natural behavior could be used as an important indicator of animal welfare. In addition, the dominance ranking obtained before male removal and the changes observed in the females’ social behavior after male removal reinforce the idea of a male influence over females.

Unfortunately and, despite the fact that female social interactions varied after male removal, our comparisons are not statistically significative. The small size of the study group, the variability of female dyadic interactions, and the short post-removal period of observation could limit our results and its later interpretations. In this regard, it would have been interesting to increase the information about the sociality of the study group with data regarding the social behavior of young females.  However, the initial procedure designed to study the group sociality in depth, did not contemplate collecting data on the social behavior of young females. Moreover, we assume that dyads respond differently to the demographic changes and that a longer period of post-removal observation could allow us to observe an evolution of the female relationships different from that observed [e.g., the development of stronger and affiliative social relationships observed by Schel et al. (2013) in chimpanzees, one year after modifying the demographic composition of the study group].

This study may be interesting from an applied standpoint, because it shows how the description of the social behavior before and after the removal of an individual from a social group, and their later comparison, can be useful for primate managers to anticipate the behavioral response of animals when facing future modifications of the group sociodemographics. In this sense, some authors (Coe, 1993; Raleigh, McGuire, Brammer, & Yuwiler, 1984; Steklis, Raleigh, Kling, & Tachiki, 1986) have stated that those events that modify the social bonds and the dominance relationships of a group may lead to behavioral and physiological signs of distress for a long time afterward. Our results show how, after male removal, females seem to cope with this social instability by creating a more peaceful scenario. Their sociality does not seem to be negatively affected in the short term by this change. Moreover, our findings confirm that factors such as the social status, the species, and the individual’s characteristics, should be considered when planning the removal of an individual from a social group of primates. We recommend elaborating an accurate plan for the individual’s removal prior to carrying it out. This plan must collect both the knowledge acquired by animal care staff over the years and that obtained through scientific studies such as ours. As a whole, the information here presented ads to the scarce literature surrounding alpha male removal in small groups of primates.

Some have examined if disgust can be evoked by contacting an object, yet none have examined if reported disgust changes when the hand leaves the object; surprising, given that post-contact tactile disgust is a driver of hand hygiene

Tactile disgust: Post-contact can be more disgusting than contact. Supreet Saluja, Richard Stevenson. Quarterly Journal of Experimental Psychology, August 24, 2021. https://doi.org/10.1177/17470218211043688

Abstract: Several studies have examined if disgust can be evoked by contacting an object – yet none have examined if reported disgust changes when the hand leaves the object. This is surprising given that post-contact tactile disgust is probably a driver of hand hygiene. We examined contact and post-contact tactile disgust and its sensory origins. Participants were asked to touch several objects, making sensory, disgust, and desire-to-handwash evaluations. These ratings were made at three stages-of-contact – object-contact (just touch), post-contact (just touch), and visual post-contact (touch, vision). Disgust was typically highest at postcontact (when the hand left the object). Stickiness and wetness were uniquely predictive of object-contact disgust. Only stickiness drove post-contact disgust, and only wetness visual post-contact disgust. Hand-washing desire was primarily driven by quantity of residue perceived on the hand. These findings suggest that tactile disgust is a multisensory and iterative process relating to object- and residue-adhesiveness.

Keywords: tactile, disgust, post-contact, hand washing desire, visual texture

Mere awareness of future improvement led participants to experience present versions as less enjoyable—even bid more money to be able to end their participation early; knowledge led these participants to perceive more flaws in present versions

The “Next” Effect: When a Better Future Worsens the Present. Ed O’Brien. Social Psychological and Personality Science, August 25, 2021. https://doi.org/10.1177/19485506211034972

Abstract: Various domains of life are improving over time, meaning the future is filled with exciting advances that people can now look forward to (e.g., in technology). Three preregistered experiments (N = 1,602) suggest that mere awareness of better futures can risk spoiling otherwise enjoyable presents. Across experiments, participants interacted with novel technologies—but, via random assignment, some participants were informed beforehand that even better versions were in the works. Mere awareness of future improvement led participants to experience present versions as less enjoyable—despite being new to them, and despite being identical across conditions. They even bid more money to be able to end their participation early. Why? Such knowledge led these participants to perceive more flaws in present versions than they would have perceived without such knowledge—as if prompted to infer that there must have been something to improve upon (or else, why was a better one needed in the first place?)—thus creating a less enjoyable experience. Accordingly, these spoiling effects were specific to flaw-relevant stimuli and were attenuated by reminders of past progress already achieved. All told, the current research highlights important implications for how today’s ever better offerings may be undermining net happiness (despite marking absolute progress). As people continually await exciting things still to come, they may be continually dissatisfied by exciting things already here.

Keywords: change over time, well-being, enjoyment, technology, contrast effects

Participants were more willing to share news they found more interesting-if-true, as well as news they deemed more accurate; they deemed fake news less accurate but more interesting-if-true than true news, & were more likely to share true news than fake news

“If This account is True, It is Most Enormously Wonderful”: Interestingness-If-True and the Sharing of True and False News. Sacha Altay, Emma de Araujo & Hugo Mercier. Digital Journalism, Aug 24 2021. https://doi.org/10.1080/21670811.2021.1941163

Abstract: Why would people share news they think might not be accurate? We identify a factor that, alongside accuracy, drives the sharing of true and fake news: the ‘interestingness-if-true’ of a piece of news. In three pre-registered experiments (N = 904), participants were presented with a series of true and fake news, and asked to rate the accuracy of the news, how interesting the news would be if it were true, and how likely they would be to share it. Participants were more willing to share news they found more interesting-if-true, as well as news they deemed more accurate. They deemed fake news less accurate but more interesting-if-true than true news, and were more likely to share true news than fake news. As expected, interestingness-if-true differed from interestingness and accuracy, and had good face validity. Higher trust in mass media was associated with a greater ability to discern true from fake news, and participants rated as more accurate news that they had already been exposed to (especially for true news). We argue that people may not share news of questionable accuracy by mistake, but instead because the news has qualities that compensate for its potential inaccuracy, such as being interesting-if-true.

Keywords: News sharingfake newsaccuracyinterestingness-if-truemisinformationsocial media

Zoo-housed gorillas: General preference for unnatural over natural sounds

Silence is Golden: Auditory Preferences in Zoo-housed Gorillas. Jordyn Truax & Jennifer Vonk. Journal of Applied Animal Welfare Science, Aug 24 2021. https://doi.org/10.1080/10888705.2021.1968400

Abstract: Enrichment is presented to improve the welfare of captive animals but sound is frequently presented with the assumption that it is enriching without assessing individuals’ preferences. Typically, presented sounds are unnatural and animals are unable to choose which sounds they can listen to or escape them. We examined preferences of three zoo-housed gorillas for six categories of sound. The gorillas selected unique icons on a computer touchscreen that initiated brief samples of silence, white noise, nature, animal, percussion, and electronic instrumental sounds. Following training, gorillas selected each sound paired with silence (Phase 2), each sound paired with each other sound (Phase 3), and one sound among all other sound categories (Phase 4). Initially, a single sound was associated with each icon, but additional exemplars of the category were added in phases 5–8. Preferences were generally stable and one gorilla showed a strong preference for silence. Although there were individual differences, a surprising general preference for unnatural over natural sounds was revealed. These results indicate the importance of assessing preferences for individuals before introducing auditory stimulation in captive habitats.

KEYWORDS: Gorillaenrichmentchoicesound

Exercise-Induced Orgasm and Its Association with Sleep Orgasms and Orgasms During Partnered Sex: About 9pct of Americans reported having ever experienced exercise-induced orgasm

Exercise-Induced Orgasm and Its Association with Sleep Orgasms and Orgasms During Partnered Sex: Findings From a U.S. Probability Survey. Debby Herbenick, Tsung-chieh Fu, Callie Patterson & J. Dennis Fortenberry. Archives of Sexual Behavior, Aug 24 2021. https://rd.springer.com/article/10.1007/s10508-021-01996-9

Abstract: Prior research has described women’s experiences with exercise-induced orgasm (EIO). However, little is known about men’s experiences with EIO, the population prevalence of EIO, or the association of EIO with other kinds of orgasm. Using U.S. probability survey data, the objectives of the present research were to: (1) describe the lifetime prevalence of exercise-induced orgasm (EIO) and sleep orgasm; (2) assess respondents’ age at first experience of EIO as well as the type of exercise connected with their first EIO; (3) examine associations between lifetime EIO experience and orgasm at respondents’ most recent partnered sexual event; and (4) examine associations between lifetime EIO experience and sleep orgasms. Data were from the 2014 National Survey of Sexual Health and Behavior (1012 men and 1083 women, ages 14 years and older). About 9% of respondents reported having ever experienced exercise-induced orgasm. More men than women reported having experienced orgasm during sleep at least once in their lifetime (66.3% men, 41.8% women). The mean age for women’s first EIO was significantly older than men (22.8 years women, 16.8 years men). Respondents described a wide range of exercises as associated with their first EIO (i.e., climbing ropes, abdominal exercise, yoga). Lifetime EIO experience was associated with lifetime sleep orgasms but not with event-level orgasm during partnered sex. Implications related to understanding orgasm and recommendations for clinicians and sex educators are discussed.

Rolf Degen summarizing... Although many individuals in committed relationships had a crush on a third party, they did not want to play out their attraction, but just to keep him/her as a silent reserve in the sidelines

Loving you from afar: Attraction to others (“crushes”) among adults in exclusive relationships, communication, perceived outcomes, and expectations of future intimate involvement. Lucia F. O’Sullivan, Charlene F. Belu, Justin R. Garcia. Journal of Social and Personal Relationships, August 24, 2021. https://doi.org/10.1177/02654075211038612

Abstract: Crushes are uncommunicated, often unilateral, attractions to an individual, generally viewed as a state of unfulfilled longing. They are typically attributed to young people, but recent research suggests that these experiences might be common among adults as well, including among those in committed relationships. Combining findings from three studies across four datasets, this mixed-methods research explores crushes experienced by individuals in committed intimate relationships. Study 1 explored types of crushes, preferences and nature of exchanges among adults in committed relationships and compares their reports to a sample of single individuals. Study 2 examined perceived outcomes of crushes as a way to assess needs or goals served by crushes. Study 3 investigated expectations about whether and how the crush relationship might evolve into a more intimate relationship. A total of 3,585 participants (22–45 years, 53.1% women) completed anonymous online surveys addressing crush experiences and related dynamics. Those in committed relationships typically did not intend to communicate their attraction to the target, unlike single individuals. Associated outcomes were primarily positive, including excitement, increased esteem, and fantasy/escape. The vast majority reported no expectations that these crushes would evolve into more intimate relationships, replacing their current relationship. This work adds to our understanding of attraction outside of traditional human courtship processes, with implications for the study of intimate relationship development and maintenance.

Keywords: Attraction, committed, crush, intimate, romantic, sexual, single

Check also Belu, C., & O'Sullivan, L. (2019). Roving Eyes: Predictors of Crushes in Ongoing Romantic Relationships and Implications for Relationship Quality. Journal of Relationships Research, 10, E2. doi:10.1017/jrr.2018.21. https://www.bipartisanalliance.com/2019/01/while-in-romantic-relationship-crushes.html

And Walk the Line: How Successful Are Efforts to Maintain Monogamy in Intimate Relationships? Brenda H. Lee, Lucia F. O’Sullivan. Archives of Sexual Behavior, June 18 2019. https://www.bipartisanalliance.com/2019/06/how-successful-are-efforts-to-maintain.html

And Why Find My Own When I Can Take Yours?: The Quality of Relationships That Arise From Successful Mate Poaching. Charlene F. Belu and Lucia F. O'Sullivan. Journal of Relationships Research, Volume 9, 2018, e6. https://www.bipartisanalliance.com/2018/05/the-quality-of-relationships-that-arise.html

General discussion

This series of exploratory studies on crushes was designed to provide some early insights into the nature of exchanges with attractive others for those in committed relationships, outcomes associated with having these attractions, and expectations of future involvement with the target of one’s attraction. Moving us beyond a focus on attraction to others as an indicator of poor relationship quality or a precursor to infidelity, the current series of studies established that these attractions most often seemed instrumental in gaining fairly positive psychosocial outcomes, such as diversion, fun, or excitement.

Overall, few individuals in ostensibly exclusive relationships reported plans to advance the crush relationship further. By comparison to singles, those in relationships were more inclined to keep their attraction covert and were more satisfied to simply flirt with someone for whom they experienced attraction rather than communicate their interest directly.

These findings raise the obvious question of why humans might exhibit and entertain feelings of crushes in the first place, if they are expected to go unfulfilled—that is, unlike in other models of attraction, an individual does not seek out the object of the crush. On the surface, this would seem to be a poor use of an individual’s time and effort, resources meant to be adaptively leveraged in mating contexts. It is possible that these crush attractions are simply inevitable, that we cannot turn off the psychological system that helps us orient toward potential partners when we enter an established relationship. The Instrumentality Principle would indicate that these behaviors meet a motivational priority, moving an individual toward a valuable goal. However, these attractions might reassure individuals that there are other options should the primary relationship falter (i.e., mate switching; Buss et al., 2017). Similarly, many young adults report maintaining “back burner” relationships, that is, a connection with someone who they might someday connect with romantically or sexually (Dibble & Drouin, 2014; Dibble et al., 2015). Crushes might comprise a means of gauging or testing one’s commitment and interest in preserving a primary relationship.

We did not assess relationship quality of one’s primary relationship. Although participants’ self-reports suggest that crushes are relatively benign experiences, further research is needed to examine under which conditions a crush might undermine relationship quality. Intensity of one’s attraction, especially if it increases over time, mutuality of the attraction and the response of the crush target should they want to pursue a relationship are likely important moderators, as is quality of the primary relationship in terms of satisfaction and commitment. Primary relationships of lower quality are likely more vulnerable to one or both partners becoming distracted by another. We also should examine more closely the impact of the secrecy involved with crushes and indeed how much is concealed from a primary partner. Secret attraction when linked with fear of its being exposed might amplify attraction through misattribution of arousal (“excitement transfer” Marin et al., 2017; Meston & Frohlich, 2003) or frustration attraction (Fisher, 2005).

Study limitations

There are other limitations that need to be acknowledged. Our use of cross-sectional data rather than longitudinal data renders any speculation about links to relationship outcomes unwarranted. A longer trajectory, ideally using prospective methods, would allow researchers to better capture outcomes associated with attractions to others. This is a limitation of the study designs, and short of tracking individuals from the onset of their relationship, one that cannot be easily overcome. In addition, it is important to bear in mind that self-reports about sensitive topics, such as attractions to others, are often subject to issues of presentation biases. However, in every case, we ensured that participants were fully informed of the anonymous nature of their reports, which we believe offset some of the biases these concerns might introduce.

Although we were able to study gender differences to some extent, we were only able to explore differences in terms of sexual identity in the first of our three studies. Those who identified as sexual minorities (gay, lesbian, or bisexual) reported more types of crushes than did those who identified as heterosexual. This finding might reflect pressure among sexual minority individuals to keep same-sex attractions hidden. Exploring these attractions in larger and/or more diverse populations will help us determine how a mechanism that evolved to guide individuals toward a viable romantic and sexual partner with whom we intend to bond and mate (Berscheid, & Reis, 1998; Fisher, 1998; Sprecher & Hatfield, 1985) operates in contexts in which an intimate relationship is ostensibly not the goal.

More intelligent individuals have a higher tendency to fish for good news

Si Chen & Carl Heese, 2021. "Fishing for Good News: Motivated Information Acquisition," CRC TR 224 Discussion Paper Series crctr224_2021_223v3, University of Bonn and University of Mannheim. https://ideas.repec.org/p/bon/boncrc/crctr224_2021_223v3.html

Abstract: The literature on motivated reasoning argues that people skew their beliefs to feel moral when acting selfishly. We study information acquisition of decision-makers with a motive to form positive moral self-views and a motive to act selfishly. Theoretically and experimentally, we find that a motive to act selfishly makes individuals 'fish for good news': they are more likely to continue (stop) acquiring information, having received mostly information suggesting that acting selfishly is harmful (harmless) to others. We find that fishing for good news may improve social welfare. Finally, more intelligent individuals have a higher tendency to fish for good news.

5 Concluding remarks

Theoretically and experimentally, this paper analyzes the effect of the trade-off between a motive to feel moral and a competing egoistic motive on individuals’ information acquisition strategies. Two features of our study stand out relative to the existing literature. First, we consider environments with rich information sources. This ensures that the predicted and the observed information choices are not confounded by exogenous limitations imposed by the study. Theoretically, it means that we characterize the globally optimal information acquisition strategy. Empirically, it allows us to observe uncensored data on the individuals’ information strategies and uncover novel phenomena. Second, we consider a baseline in which the egoistic motive is removed from the decision. Comparing this baseline with the scenario with an egoistic motive, we can study the causal effects of the trade-off between competing motives. Three main findings emerge: first, having competing motives makes individuals fish for good news. Specifically, individuals are more likely to continue acquiring information after receiving information suggesting negative externalities of a selfish decision (‘bad news’). Reversely, after receiving information indicating no harm (‘good news’), individuals are more likely to stop. Second, theoretically, fishing for good news may improve social welfare. This prediction is supported by our data. Finally, the tendency to fish for good news is stronger among individuals with above-median cognitive ability— evidence that fishing for good news is more likely a strategic behaviour than a result of cognitive limitations. The paper opens up directions of future research. The key feature of our setting is that the decision-maker has two competing motives—one urging the individual to choose a particular action, and the other urging her to act upon her belief about an unknown state. Such a trade-off is present in many economic contexts beyond moral decisions. Imagine a food lover presented with a delicious new dish. While she longs for the dish, she also wants to believe that the food that she consumes is healthy. How would she inquire about the 40 nutrition facts of the food? Similar trade-offs arise for example in smoking and workout decisions.32 Besides, it might be interesting to investigate information acquisition strategies in field settings where morality and egoism might clash. Last, the theoretical model can be used to study other questions about individuals’ information preferences—a recently active area of empirical research.33 For example, one may analyze preferences over information skewness in settings where individuals have two competing motives. 

Individuals with high digital literacy are less likely to fall for fake news, but no less willing to share those

Sirlin, Nathaniel, Ziv Epstein, Antonio A. Arechar, and David G. Rand. 2021. “Digital Literacy and Susceptibility to Misinformation.” PsyArXiv. August 21. doi:10.31234/osf.io/7rb2m

Abstract: It has been widely argued that social media users with low digital literacy – who lack fluency with basic technological concepts related to the internet – are more likely to fall for online misinformation, but surprisingly little research has examined this association empirically. In a large survey experiment involving true and false news posts about politics and COVID-19, we find that digital literacy is indeed an important predictor of the ability to tell truth from falsehood when judging headline accuracy. However, digital literacy is not a significant predictor of users’ intentions to share true versus false headlines. This observation reinforces the disconnect between accuracy judgments and sharing intentions, and suggests that interventions beyond merely improving digital literacy are likely needed to reduce the spread of misinformation online.

The androgynous brain is advantageous for mental health and well-being

Brain sex differences: the androgynous brain is advantageous for mental health and well-being. Qiang Luo & Barbara J. Sahakian. Neuropsychopharmacology, Aug 16 2021. https://www.nature.com/articles/s41386-021-01141-z

Abstract: Studies of personality and sex differences have reported that male’s and female’s basic personality traits appear to differ on average, in several respects [1]. From a psychological perspective, these sex differences are thought to result from perceived gender roles, gender socialisation and socio-structural power differentials, although the evolutionary theory has also been used to explain these differences [1]. However, psychological studies have already suggested that people can be androgynous, having mixed personality traits that are stereotypically considered to be male or female [2]. Furthermore, most of us are in fact probably somewhere on a spectrum between what we stereotypically consider a male or a female [2].

Check also Does gender role explain a high risk of depression? A meta-analytic review of 40 years of evidence. Jingyuan Lin et al. Journal of Affective Disorders, Volume 294, Nov 1 2021, Pages 261-278. Androgynous individuals are less likely to suffer depression while undifferentiated individuals are more susceptible to depression; masculinity traits seem to be a robust protective factor for depression regardless of gender

Nudges are behavioral interventions to subtly steer citizens’ choices toward “desirable” options: Mapping Conditions of Susceptibility to Nudge Influence

Nudgeability: Mapping Conditions of Susceptibility to Nudge Influence. Denise de Ridder, Floor Kroese, Laurens van Gestel. Perspectives on Psychological Science, August 23, 2021. https://doi.org/10.1177/1745691621995183

Abstract: Nudges are behavioral interventions to subtly steer citizens’ choices toward “desirable” options. An important topic of debate concerns the legitimacy of nudging as a policy instrument, and there is a focus on issues relating to nudge transparency, the role of preexisting preferences people may have, and the premise that nudges primarily affect people when they are in “irrational” modes of thinking. Empirical insights into how these factors affect the extent to which people are susceptible to nudge influence (i.e., “nudgeable”) are lacking in the debate. This article introduces the new concept of nudgeability and makes a first attempt to synthesize the evidence on when people are responsive to nudges. We find that nudge effects do not hinge on transparency or modes of thinking but that personal preferences moderate effects such that people cannot be nudged into something they do not want. We conclude that, in view of these findings, concerns about nudging legitimacy should be softened and that future research should attend to these and other conditions of nudgeability.

Keywords: nudges, awareness, preferences, dual-process models

Discussion

In this article, we examined conditions that determine people’s susceptibility to nudge influence in an effort to probe common assumptions about when nudges are effective in guiding people’s choices. Although it has been repeatedly emphasized that nudges are “gentle directions” to promote decisions in people’s own best interest, there has been considerable debate about nudging legitimacy insofar as it may violate principles of good public policy that require transparency, acknowledgment of citizen preferences, and a reasonable degree of informed decision-making. We have highlighted these issues from the viewpoint of nudge effectiveness to determine nudgeability under conditions of disclosure of nudge presence and purpose, nudge-congruent and nudge-incongruent preferences, and either or not being able to deliberate on one’s choice (System 1 or System 2 processing).

Our review reveals that people are equally responsive to nudges regardless of whether their presence, purpose, or working mechanisms are disclosed—suggesting that transparency does not compromise nudge effects. Our analysis also shows that preexisting preferences matter insofar as nudges prove generally ineffective when not concordant with goals and intentions. Rather, nudges appear to have the greatest impact on choice when people have less developed preferences because they are ambivalent or in doubt about their choice. We further showed that nudges are not specifically effective when people are in a System 1 state of mind, which would, according to the prevailing assumption, make them more susceptible to nudge influence. It is uncertain, however, to what extent explicit encouragement to reflect on choices may attenuate nudge effects, although potentially weaker effects after a consideration of options may also be due to more articulated preferences.

Together, these findings call for greater scrutiny of the theoretical underpinnings of nudges. Nudges have been presented as typical System 1 devices targeting heuristics and biases that would require unawareness of their influence while, according to some (Bovens, 2009; Steffel et al., 2016), disregarding people’s preferences for a particular choice. More recent theoretical work displays growing attention for a new generation of nudges that explicitly target System 2 processes (Sunstein, 2016). “Overt” System 2 nudges that are easy to discern are generally better accepted by the target population (Bang et al., 2018; Felsen et al., 2013; Jung & Mellers, 2016; Sunstein, 2016), presumably because they do not rely on “unconscious processing.” Moreover, System 2 nudges are expected to boost people’s decision-making capacities (Hertwig, 2017; Hertwig & Grüne-Yanoff, 2017). Although these novel types of nudges may thus potentially be more (or at least equally) effective and more legitimate, our review shows that “traditional” nudges already do not depend on being hidden and operating in the dark.

In view of these findings, note that this initial review primarily serves the purpose of agenda setting. More systematic research on which conditions make people more (or less) responsive to nudges is warranted. This applies to all three dimensions of nudgeability that our central to our review. Once more evidence becomes available on these factors, a meta-analytic synthesis of the literature would give a deeper insight into how each of these factors determines nudgeability. Future research should also take into account what type of nudge is involved. As alluded to in the introduction, “nudge” is an umbrella term that relates to many types of interventions. A better categorization of nudges in general and a particular focus on the relevance of a distinction between so-called System 1 nudges (of which people are supposedly unaware) and System 2 nudges (that aim to support people in reflecting upon their choices) are needed to make a significant step forward in unraveling when and why people are susceptible to the influence of nudges.

Examining the role of the type of nudge is important because many studies on the conditions of nudge effectiveness have been conducted with defaults, which are considered to exert the strongest influence on choice and thus provide a critical test of nudgeability. However, even in view of the finding that default effects remain after disclosure and are weakened when they do not accord with preferences, concerns about the deceitful nature of defaults have persisted (Steffel et al., 2016). It is therefore urgent to systematically address softer categories of nudges such as repositioning, framing, and salience (Keller et al., 2011) and examine whether our observations on nudgeability apply to these milder classes of nudges.

In addition to a more systematic synthesis of research into nudgeability incorporating the type of nudge, a number of topics require more research to find out whether they affect susceptibility to nudge influence. This especially applies to the source of the nudge, the complexity of the issue of interest, as well as to the role of SES—topics we could touch on only briefly because of the lack of empirical evidence. In particular, nudgeability of disadvantaged groups is a topic that should be put high on the agenda for future research, as nudges are supposed to benefit the health, wealth, and happiness of all. Not much is yet known about the potential distributional consequences of nudges, as only a few studies have examined the extent to which nudges specifically would affect people from disadvantaged groups. Whereas some studies have suggested that people from low-SES groups are more responsive to default nudges (either or not to their own benefit), other studies have indicated that poor people benefit from nudges in a way that they would not have from conventional policy instruments, such as informational campaigns (Hotard et al., 2019).

Once again, we would like to emphasize that our review is a first attempt to document nudgeability with a specific focus on elements that have been generated in debates on nudging legitimacy. More research on other facets that are so far absent in studies on moderators of nudge effects is much needed for the systematic documentation of the conditions that make people responsive to nudges. An important candidate for further study is self-regulatory capacity, or the extent to which people can identify relevant goals and act on them. Theoretically, people with poor self-regulatory capacity might experience greater benefit from nudges, but as of yet it is unknown whether people with low competence to regulate their behavior are more or less susceptible to choice guidance. Initial research suggests that people with low trait self-control are somewhat less responsive to nudging than those who have high trait self-control (Thunström, 2019). However, whether people with poor self-regulatory skills are nudgeable may critically depend on self-insight; people who have less self-knowledge may be more opposed to nudges than those who have more self-knowledge. Social connectedness is another feature that may explain heterogeneous responses to nudges. Decision makers who have few social ties and only a few friends serve as potential role models for questions about important choices might be more susceptible to nudges that function as social cues when in doubt, as is also demonstrated in defaults serving as (implicit) recommendations for a certain choice.

Finally, returning to the debates on nudging legitimacy that we addressed at the beginning of this article, it seems that concerns should be softened insofar as nudges do impose choice without respecting basic ethical requirements for good public policy. More than a decade ago, philosopher Luc Bovens (2009) formulated the following four principles for nudging to be legitimate: A nudge should allow people to act in line with their overall preferences; a nudge should not induce a change in preferences that would not hold under nonnudge conditions; a nudge should not lead to “infantilization,” such that people are no longer capable of making autonomous decisions; and a nudge should be transparent so that people have control over being in a nudge situation. With the findings from our review in mind, it seems that these legitimacy requirements are fulfilled. Nudges do allow people to act in line with their overall preferences, nudges allow for making autonomous decisions insofar as nudge effects do not depend on being in a System 1 mode of thinking, and making the nudge transparent does not compromise nudge effects.

How are gene variants associated with same-sex sexual behaviour maintained in the gene pool? New study suggests that the same variants, when found in individuals who don't engage in SSSB behavior, are associated with having more sexual partners

Genomic evidence consistent with antagonistic pleiotropy may help explain the evolutionary maintenance of same-sex sexual behaviour in humans. Brendan P. Zietsch, Morgan J. Sidari, Abdel Abdellaoui, Robert Maier, Niklas Långström, Shengru Guo, Gary W. Beecham, Eden R. Martin, Alan R. Sanders & Karin J. H. Verweij. Nature Human Behaviour, August 23 2021. https://www.nature.com/articles/s41562-021-01168-8

Abstract: Human same-sex sexual behaviour (SSB) is heritable, confers no immediately obvious direct reproductive or survival benefit and can divert mating effort from reproductive opportunities. This presents a Darwinian paradox: why has SSB been maintained despite apparent selection against it? We show that genetic effects associated with SSB may, in individuals who only engage in opposite-sex sexual behaviour (OSB individuals), confer a mating advantage. Using results from a recent genome-wide association study of SSB and a new genome-wide association study on number of opposite-sex sexual partners in 358,426 individuals, we show that, among OSB individuals, genetic effects associated with SSB are associated with having more opposite-sex sexual partners. Computer simulations suggest that such a mating advantage for alleles associated with SSB could help explain how it has been evolutionarily maintained. Caveats include the cultural specificity of our UK and US samples, the societal regulation of sexual behaviour in these populations, the difficulty of measuring mating success and the fact that measured variants capture a minority of the total genetic variation in the traits.

Popular version: Genetic patterns offer clues to evolution of homosexuality. Sara Reardon. Nature News, Aug 23 2021. https://www.nature.com/articles/d41586-021-02312-0