Personality disorders reveal much stronger sex differences than normal personality traits, with men leaning much more towards the "dark" side

Sex in the dark: Sex differences on three measures of dark side personality. Adrian Furnham, George Horne. Acta Psychologica, Volume 234, April 2023, 103876. https://doi.org/10.1016/j.actpsy.2023.103876

Abstract: This study examined sex differences in the scores on three different measures of the personality disorders (PDs) all derived from on-line surveys. Two groups (total N = 871) completed the Coolidge Axis-II Inventory which assessed 14 PDs; two groups (total N = 732) completed the Short Dark Tetrad which assessed 4 PDs; four groups (total N = 1558) completed the Personality Inventory for DSM-5—Brief Form which assessed 5 PD dimensions. Cohen's d after ANOVAs, and binary regression analysis revealed consistent findings. In this study we calculated 63 d statistics of which 5 were d > 0.50 and 28 were d > 0.20. In two samples, each using two different instruments, men scored higher than women on Anti-Social, Narcissistic and Sadistic PD which is a consistent finding in the literature. Speculations are made about the origin of these differences. Limitations are acknowledged.

Keywords: SexPersonalityTraitsDisordersEffect sizeBright/dark side

4. Discussion

The results of this study are largely consistent with previous research in this area, and confirms they hypotheses. This paper raises a number of points. First, the consistency of the PD sex differences across samples who took the same test, and second across PDs measured between different tests. With regard to the consistency between samples there seemed “reasonable” agreement particularly with those that were most and least significantly different. In all, we had eight participant groups with an 232 < N < 506 who were recruited on-line. In no instance did analyses show opposite results with the exception of one group tested on the DSM-5 where men scored higher than women on the Negative Affectively scale in contrast to the other three groups. Thus, we have demonstrated the generalisability of results across very different measures, in eight different samples.

A major question concerns sex differences in “bright-” as opposed to “dark-side” traits. Furnham and Treglown (2021) who looked at six tests found the Cohen's d statistic showed very few (3 out of 130) differences >0.50. In a study of dark-side traits, Furnham and Grover, 2022a, Furnham and Grover, 2022b found a Cohen's d statistic showed very few (5 out of 44) differences >0.20. In this study however we calculated 63 d statistics of which 5 were d > 0.50 and 28 were d > 0.20. Thus, it appears there are more differences on dark-, as opposed to bright-side measures. This finding requires an explanation and further investigations. However, we have to acknowledge that overall, there are both relatively few and small sex differences, an observation made by many in this area.

We were also able to compare sex differences on different measures of the same trait as the SCATI and the Dark Tetrad both measured Anti-Social, Narcissistic and Sadistic PD. This was consistent between the samples and the instruments showing the following d scores: Anti-Social: 0.30, 0.28, 63, 0.69; Narcissistic: 0.26, 0.84, 0.32, 0.83 and Sadistic PD 0.41; 0.25, 0.80, 0.49. These results confirm the previous literature on Anti-Social and Narcissistic PD but highlight the role of Sadistic PD which, admittedly does not appear as a PD in any of the DSM manuals (American Psychiatric Association, 2000, American Psychiatric Association, 2015). It explains also why so many studies on powerful derailed individuals nearly always highlight men rather than women (Babiak & Hare, 2006).

An examination of the Binary Logistic Regressions showed that the Exp(B) varied mainly between 0.80 and 1.20 the lowest being 0.63 for Antagonistic for Group 1 and the highest being 1.68 for Negative Effect for Group 1. Again, depending on cut-interpretations these could be considered high or low.

However, it does appear from this data that having a PD is predominantly a “male problem” in that on all four Tetrad traits, and four of the five DSM-5 dimensions males scored significantly higher than females across all samples. The SCATI did show that where there were consistent findings across the two samples and a d > 0.10 women did score higher on Borderline, Dependent, and Schizotypal, which has been established in previous studies.

There appears to be relatively little theoretical development in the PD literature about the “causes” of the different PDs that may lead to very clear hypothesis testing. Whilst it would not be difficult to develop an evolutionary-based theory explaining why men might be higher on Anti-Social and Narcissistic PD it seems much more difficult to explain why women might score more highly on other PDs like Borderline or Schizotypal. In this sense few of the sex difference studies in PD are theoretically, rather than psychometrically, driven.

5. Conclusion

The strengths of this paper was to report sex difference in the PDs using multiple measures (three) and multiple samples (eight). The results suggest that compared to studies of sex differences in bright-side (normal) personality where sex differences are common but small, sex differences in (some) dark-side traits are consistently larger.

This study has implications for the theory, measurement and indeed treatment of the PDs. From an evolutionary psychology perspective it seems possible to explain some of these differences: for instance, why boldness, fearlessness and self-confidence maybe beneficial to males, though in excess a disadvantage. Equally it may be possible to explain some sex differences in the traditional socialisation of children into established sex roles.

As the movement of PD researchers from a categorical to a dimensional perspective progresses we should be able to inspect sex differences seeking to establish consistency of findings and following that explanations.

6. Limitations

There are frequent critiques that online survey data is often problematic with participants being perfunctory in their responses. In each study we included IQ items as well as other checks to be able to inspect the quality of the responses. In most studies we removed a small number of participants before the analysis with concerns about the quality of their data.

This study explored the data bank of a research group. Nearly all the participants were functioning working adults and not a student or clinical sample, though it is possible that a small number were present in each study. Although we had a lot of data on each participant it was not consistent between samples. Furthermore, it would have been desirable to have a lot more data on each person such as their education and general mental health.

Of the two categorical measures the SCATI has been used in a number of studies and appears to have adequate psychometric properties but is not a particularly well-known measure. The Dark Tetrad measure on the other hand is relatively new though attracting a good deal of attention (Alavi et al., 2022; Fernández-del-Río et al., 2022; Jain et al., 2022). However, the DSM-5 is now 10 years old and has been used in many studies. Studies such as this serve to describe sex differences but give no indication in their cause or consequence. Thus, they can show that differences exist but not why.

Income and emotional well-being

Income and emotional well-being: A conflict resolved. Matthew A. Killingsworth, Daniel Kahneman, and Barbara Mellers. Proc. Natl. Acad. Sci., March 1 2023, 120 (10) e2208661120. https://doi.org/10.1073/pnas.2208661120

Significance: Measures of well-being have often been found to rise with log (income). Kahneman and Deaton [Proc. Natl. Acad. Sci. U.S.A. 107, 16489–93 (2010)] reported an exception; a measure of emotional well-being (happiness) increased but then flattened somewhere between $60,000 and $90,000. In contrast, Killingsworth [Proc. Natl. Acad. Sci. U.S.A. 118, e2016976118 (2021)] observed a linear relation between happiness and log(income) in an experience-sampling study. We discovered in a joint reanalysis of the experience sampling data that the flattening pattern exists but is restricted to the least happy 20% of the population, and that complementary nonlinearities contribute to the overall linear-log relationship between happiness and income. We trace the discrepant results to the authors’ reliance on standard practices and assumptions of data analysis that should be questioned more often, although they are standard in social science.

Abstract: Do larger incomes make people happier? Two authors of the present paper have published contradictory answers. Using dichotomous questions about the preceding day, [Kahneman and Deaton, Proc. Natl. Acad. Sci. U.S.A. 107, 16489–16493 (2010)] reported a flattening pattern: happiness increased steadily with log(income) up to a threshold and then plateaued. Using experience sampling with a continuous scale, [Killingsworth, Proc. Natl. Acad. Sci. U.S.A. 118, e2016976118 (2021)] reported a linear-log pattern in which average happiness rose consistently with log(income). We engaged in an adversarial collaboration to search for a coherent interpretation of both studies. A reanalysis of Killingsworth’s experienced sampling data confirmed the flattening pattern only for the least happy people. Happiness increases steadily with log(income) among happier people, and even accelerates in the happiest group. Complementary nonlinearities contribute to the overall linear-log relationship. We then explain why Kahneman and Deaton overstated the flattening pattern and why Killingsworth failed to find it. We suggest that Kahneman and Deaton might have reached the correct conclusion if they had described their results in terms of unhappiness rather than happiness; their measures could not discriminate among degrees of happiness because of a ceiling effect. The authors of both studies failed to anticipate that increased income is associated with systematic changes in the shape of the happiness distribution. The mislabeling of the dependent variable and the incorrect assumption of homogeneity were consequences of practices that are standard in social science but should be questioned more often. We flag the benefits of adversarial collaboration.

Deceptive affection is strategically expressed under relational threat—but not towards partners with low mate value

Deceptive affection is strategically expressed under relational threat—but not towards partners with low mate value. Neil R. Caton and Sean M. Horan. Journal of Social and Personal Relationships, March 6, 2023. https://doi.org/10.1177/02654075231152909

Abstract: Individuals sometimes express affection that they do not feel. This describes deceptive affectionate messages and occurs when communicators express affectionate messages that are not consistent with their internal feelings of affection in the moment. They are commonly expressed in romantic relationships (about 3 times per week) and are argued to function as relational maintenance and retention. The present work (N = 1993) demonstrated that deceptive affectionate messages are the behavioral output of an evolved psychological system that strategically operates to maintain significant pair bonds (i.e., high mate value partners) but not non-significant pair bonds (i.e., low mate value partners). This system is uniquely and nonrandomly designed to increasingly generate deceptive affectionate messages when the individual’s highly valued partnership is perceived to be under relational threat and decreasingly deploy deceptive affectionate messages when the highly valued partnership is not under threat, but the system does not apply this relational strategy in low-valued partnerships. This supports evolutionary psychological reasoning that affectionate communication should be predicated on a cost–benefit ratio, such that deceptive affectionate messages are expressed to high value mates because the substantial costs of losing a highly valued partner outweigh the smaller risks of enacting them (e.g., discovered deception, temporary relational conflict). By establishing that deceptive affection is predicated on a cost–benefit ratio, the present work better solidifies deceptive affection, and affection exchange theory more broadly, in the human evolutionary sciences.

Rather than generating the filter bubbles that pundits keep hallucinating, googling for political information drives individuals toward sources that are different to their routinary visits

Search engine effects on news consumption: Ranking and representativeness outweigh familiarity in news selection. Roberto Ulloa and Celina Sylwia Kacperski. New Media & Society, Mar 6 2023. https://doi.org/10.1177/14614448231154926

Abstract: While individuals’ trust in search engine results is well-supported, little is known about their preferences when selecting news. We use web-tracked behavioral data across a 2-month period (280 participants) and we analyze three competing factors, two algorithmic (ranking and representativeness) and one psychological (familiarity), that could influence the selection of search results. We use news engagement as a proxy for familiarity and investigate news articles presented on Google search pages (n = 1221). We find a significant effect of algorithmic factors but not of familiarity. We find that ranking plays a lesser role for news compared to non-news, suggesting a more careful decision-making process. We confirm that Google Search drives individuals to unfamiliar sources, and find that it increases the diversity of the political audience of news sources. We tackle the challenge of measuring social science theories in contexts shaped by algorithms, demonstrating their leverage over the behaviors of individuals.

Discussion

We tested the hypothesis of news engagement (as a proxy for familiarity with news sources) as a predictor of news article selection in the Google search engine (RQ1). We did not find evidence supporting this. Instead, we found a significant effect for two factors that are decided by the search engine alone: the position in which the result is presented (ranking) and the number of times the news source appears (representativeness). While ranking has previously been demonstrated to play a strong role (Pan et al., 2007; Urman and Makhortykh, 2021), we show for the first time that its effect is weaker for news article selection compared to non-news selection (RQ3). This may well suggest a more careful decision-making process of individuals when selecting news (e.g. reading the titles and excerpts more attentively).

Research has indicated a higher representation of “mainstream” news sources in search results (Puschmann, 2019), while, at the same time, a positive effect in the diversity of news consumption (Fletcher et al., 2021; Fletcher and Nielsen, 2018). Our results align with this seemingly counter-intuitive evidence: representativeness reduced the likelihood of news article selection (RQ1). This might be an indication that once individuals have decided not to visit a result belonging to a specific news source, they also discard subsequent results from the same source, suggesting that the individual is actively avoiding such sources (Mukerjee and Yang, 2021).

In line with previous research (RQ2a), we found that Google Search increases the diversity of participants’ news consumption (Fletcher et al., 2021; Fletcher and Nielsen, 2018; Scharkow et al., 2020). It is possible that participants use Google Search when they are actively looking for novel news sources, though we also show that Google Search facilitates a discovery process by presenting a variety of news sources among the results. In addition, we show that Google Search increases the political audience diversity that news sources receive (RQ2b). Given that Google has its own news quality controls in place (Google Developers, 2021), the finding can explain recent research showcasing that political audience diversity can be used as a sign of news source reliability, and that it should be incorporated into ranking algorithms (Bhadani et al., 2022). Instead, our results suggest that it is Google Search (including its ranking) that drives this effect. More broadly, researchers should consider that online news browsing behavior is heavily shaped by online platforms, for example, we demonstrated that there are differences in the consistency of our familiarity metric depending on whether it is measured including traffic referred by Google or not. Considering the dominance of a few large search engines and their role in driving users to news, the situation may lead to a concentration of power and influence within the media landscape in which news organizations prioritize visibility on search engines (and similar platforms) by following SEO guidelines, instead of focusing on journalistic norms (Hackett, 1984; Muñoz-Torres, 2012).

Furthermore, we build on previous research investigating the phenomenon of mere-exposure (Montoya et al., 2017) and trust in news sources (Fletcher and Park, 2017), and investigated familiarity (RQ1), that is, the participants’ acquaintance with the news sources they are presented in the search results. We proposed news engagement as a proxy and measured it using a section of the browsing history that is independent from the analyzed news articles that are selected (and visited) in the search results. This allowed us to quantify the existent relationship between the individual preferences toward news sources through the number of visits of the individual to each news domain; thus, capturing three modes of news engagement: routinary visits, social media referrals, and intentional search (Möller et al., 2020).

To summarize, we find no evidence in favor of filter bubbles, nor do we find an effect of selective exposure toward news sources based on familiarity. We find that individuals place their trust in Google, and that in turn, Google steers them toward sources that are different to their routinary visits. In this process, we tackle the challenge of developing reliable measurement models when integrating social science theory with digital behavioral data (Wagner et al., 2021).

Limitations and future directions

We would like to point out several limitations. First, our engagement metric does not fully capture when individuals are familiar and trust a given source, that is, when they do not regularly consume news or mainly do it offline. In addition, the engagement for the time independent analysis was calculated using an arguably short period of time (~1 month). Future data collections should enable analyses across timespans of multiple months up to years, though we highlight that our results did not change when considering a time-dependent analysis (~2 months).

Second, our analysis is limited to Google, which we chose due to its market dominance (StatCounter, 2021). Our findings should not be generalized to other search engines due to differences in how search results are displayed, though it is likely that effects specifically related to ranking and representativeness will remain similar across different interfaces. Our findings should also not be generalized to contexts beyond the top-10 organic results of web searches, such as carousels and top stories, news aggregators (Google News), or recommendation systems such as Google Discover. The latter does not provide results based on prompts input by the user, but presents content (including news) personalized from individuals’ preferences, which may be extracted from previous search behavior. Since search choices are heavily influenced by ranking, the algorithmic representations of preferences might also reflect the ranking effects as individual traits. This raises questions about the extent to which preferences can be captured by these systems, or if they merely expand the influence of the search engine. It highlights a challenge for study of new media: how can we better understand interdependencies between the digital services, rather than studying them in isolation?

Third, characteristics of our sample should be kept in mind when interpreting our results. The sample size used in the above research is relatively small. Out of the 739 individuals that participated in the web tracking study overall, only 280 are represented in our subsample, due to a relatively low number of news visits (including the ones driven by Google Search) in web tracking data—consistent with previous literature (Scharkow et al., 2020; Wojcieszak et al., 2021), and the strict data quality constraints for including a search page for the analysis. Our sample is relatively uniform, only including German individuals with a Chrome or Firefox browser installed on their desktop computers; while this reduces noise, it also affects generalizability of the findings. Finally, many individuals refuse to participate in web tracking studies due to privacy concerns (Makhortykh et al., 2021), which might indicate that the sample is pre-selected based on factors that we don’t yet fully understand and cannot control for.

Despite these limitations, the logged web browsing behavior that we capture occurs in a real environment with minimal intervention; we argue that cognitive awareness of the presence of the web tracker is likely to only affect the very initial browsing behavior. Moreover, web tracking studies that include the website content remain rare, and our method is exceptional as it deterministically identifies referrals by tracing the tab activity of the browser and matching the presence of the URLs among the results.

Some promising directions emerge for new media research. Our results suggest that ranking is less important for news selection: research should further confirm if individuals are more selective when choosing news from the top-10 search results, which could for example be achieved by analyzing the duration of the interaction with the individual choices or by applying eye-tracking methodologies. In addition, we find that representativeness is negatively associated with news selection. A further inspection of the reasons is of interest, for example, this behavior might signal an active avoidance of specific news sources (Mukerjee and Yang, 2021). Finally, it is important to examine search choices within the broader context of the layout of web search pages, including features like video carousels and top stories, to gain a deeper understanding of how individuals make decisions for information acquisition.

The use of social media only stirs up political anger in people who strongly embrace like-minded content, while even heavy users without such blinders become less angry

Birds of a Feather Get Angrier Together: Social Media News Use and Social Media Political Homophily as Antecedents of Political Anger. Zicheng Cheng, Hugo Marcos-Marne & Homero Gil de Zúñiga. Political Behavior, Mar 6 2023. https://link.springer.com/article/10.1007/s11109-023-09864-z

Abstract: A significant body of literature within political communication revolves around the constructive political virtues and blighting social and democratic consequences of political anger. For the most part, studies have focused on identifying the primary causes and antecedents of political anger. However, within the context of social media, fewer efforts have been devoted to clarifying how and what infuriates people about politics. Does social media news use relate to increased or reduced levels of political anger? Do social media political homophilic networks explain political anger? And to what extent does political homophily influence the potential effect of social media news use on citizens’ political anger levels—moderating effect? Results drawing on a two-wave U.S. survey dataset show that the frequency of social media news use alone has no direct effect on people’s increased political anger, whereas interacting in homophilic discussion and information networks on social media positively associates with anger. Furthermore, the relationship between social media news use and political anger is contingent upon social media political homophily. Those who report high levels of social media news use and very low levels of social media political homophily end up being less angry over time. Limitations and steps for future research are discussed in the manuscript.

Discussion

Anger is an important political emotion that holds an ambivalent relationship with democracy. While it may serve the powerless to question the political order (Lyman, 2004) and trigger constructive politics before conflicts escalate (Tagar et al., 2011), political anger is also associated with biased assimilation, fueling ideological bias in the acceptance of political information that aligns with one’s opinion (Weeks, 2015). Anger also relates to reliance on pre-existing heuristics and stereotypes (Suhay & Erisen, 2018), increased incivility, hostility, and distrust (Hasell & Weeks, 2016), less willingness to compromise (Mackuen et al., 2010; Wollebæk et al., 2019), and even with violence (Claassen, 2016). Acknowledging the wide range of consequences associated with political anger, this study focused on its social media roots.

Our analysis shows the importance of considering social media political homophily to understand political anger in online environments. Higher levels of social media political homophily do not only associate with political anger, but they also moderate the oftentimes empirically elusive relationship between social media news use and political anger. While social media news use does not contribute to explaining political anger directly, individuals who rank low on social media political homophily will be less angry about politics the more they use social media to consume information about public affairs. More importantly, the direct and moderating effect of social media political homophily on political anger is consistent across all models tested in this study: cross-sectional, lagged, and autoregressive.

Plenty of research has considered whether social media use would produce more homogeneous (Adamic & Glance, 2005; Conover et al., 2011; Feller et al., 2011) or heterogeneous (Choi & Lee, 2015; Kim, 2011; Lee et al., 2014) online environments. Our findings suggest that these studies are of the highest importance to unravel the association between social media news use and political anger. Our findings also suggest that there is no unified answer to social media news. That is, it is not solely about whether people use social media for news or not, but rather other political and communicative predispositions making individuals connect more often with like-minded people and expose themselves to ideologically congruent news. Then, they will be more likely to ‘fall victim’ to the hyper-partisan news and discussion environments which are featured with blame-attribution, moralization, and identity politics framing (Barberá, 2020; Hameleers et al., 2018; Rydell et al., 2008), thus eliciting negative effects like anger. In other words, how people consume social media and curate their news feed exerts an influence on political anger.

Our results demonstrate that whether social media news use is associated with political anger is contingent upon how the specific informational and discussion affordances that social media also provide, more specifically, whether they actively and purposively curate homophilic or heterogeneous social media news and discussion networks. Cinelli et al. (2021) suggested that aggregation of homophilic users dominates the interaction dynamics on social media like Facebook and users tend to seek information that is consistent with his/her preexisting opinion and favor the interaction with like-minded peers, and this situation leads to the formation of polarized groups online. Alternatively, Dubois and Blank (2018) found that a diverse media diet, including news use on multiple media outlets, will direct social media news users toward more diverse information and perspectives, reducing the likelihood of getting into the echo chamber. Results by Guess (2021) are particularly important in this regard, as he demonstrates that most people, at least in the U.S., interact in relatively heterogeneous environments online. While our paper remains agnostic as to the extent to which online homophily is present, the main results provide support for the idea that social media political homophily, when present, matters not only in the context of creating political segregation (Conover et al., 2011), spreading misinformation (Del Vicario et al., 2016), or strengthening group identity (Yardi & boyd, 2010), but also in explaining political anger.

This study adds some nuance to the understanding of social media news users by connecting social media political homophily, social media news use, and political anger. Prior research has suggested that affective polarization is on the rise in the U.S. and that some predicting factors, such as selective exposure (Levendusky, 2013; Tsfati & Nir, 2017) and negative political news coverage (Schmuck et al., 2020), may explain that trend. Our study contributes to filling the research gap by looking into the link between social media use patterns and people’s emotional responses to politics (i.e., political anger). Drawing on our findings, promoting a more heterogeneous social media news use and discussion network can provide an alternative pathway to reducing political anger in the American public. Although political anger has been found to mobilize the public and stimulate political actions, it increases incivility and hostility (Hasell & Weeks, 2016), causes political violence (Claassen, 2016), and exacerbates partisanship and political polarization (Huber et al., 2015). Our results suggest that by altering how individuals engage with social media news people may become less angry, which may trigger a subsequent array of democratically beneficial outcomes such as political tolerance, and less political dogmatism, as well as affect changes in people’s political behavior (Rathnayake & Winter, 2017). From the policy-making perspective, reducing homophily in people’s social and informational networks also seems to be the key. Social media platforms shall address the disadvantages brought by algorithmic news personalization, and efforts should be made to provide social media users with diverse information content, encourage users to follow accounts with opposing views, and interact with peers and news sources that encompass dissimilar political beliefs.

Albeit important, the study is not immune to limitations. There are several shortcomings that must be acknowledged and that might ideally serve as an orientation for further research on the relationship between social media news use, social media political homophily, and political anger. First, while political anger is widely spread across countries, our survey data was collected in a single country, the U.S., and even though it is a panel dataset, it is based only on one year, 2019. In this sense, while the autoregressive models have shown that overall levels of political anger vary to a moderate extent in four months, it is important to see whether choosing a different time lag will make our variables of interest gain more importance (Eveland & Morey, 2011). We also encourage future studies to examine how the link between anger and political behavior may differ across racial groups (Phoenix, 2019), as this study controls for a non-granular white versus minorities dichotomy, and further racial effect nuances may be possible (Magee & Louie, 2016).

Similarly, additional works, comparative in nature, may shed light on the existence of different patterns between social media political homophily and political anger with various degrees of overall anger in the country. Macro, meso, and individual measurement instruments may prove useful here. For instance, there might be country-level moderators for the relationship identified such as the country’s economic condition (Rico et al., 2020), ethnically located injustice (Holmes, 2004), and/or sexism culture (Kay, 2019). Additionally, we measured social media news use and social media political homophily with a self-report survey, which is subject to recall bias and social desirability bias (Scharkow, 2016). As computational methods are increasingly integrated into political communication research, it would be interesting to measure social media news use and social media political homophily with behavioral tracking data. While future studies can adopt more unobstructive measures to palliate potential bias, recent research consistently shows that although self-reported and tracking data on social media news use encompass discrepancies, overall, they positively correlate (Ernala et al., 2020; Haenschen, 2020), which minimizes the impact of this limitation. Besides, it is worth noting that the behavioral tracking data is also subject to measurement error due to the variations of the operating system setting (Jones-Jang et al., 2020), which yields a caveat for using the tracking data as an objective benchmark. As suggested by Jürgens et al. (2020), future work can address the methodological challenge by developing a more advanced digital trace tracking tool, using source-and-issue-specific survey questions, employing longitudinal survey designs (which is done in our study), and combining different data sources. Overall, this study helps clarify the informational and network discussion antecedents of political anger, in a modest but much-needed empirical assessment for the field.

Severe Sexual Sadism scores were positively associated with strategic emotional intelligence (the ability to understand and manage emotions), but were not significantly related to Experiential EI

Emotional intelligence in incarcerated sexual offenders with sexual sadism. Daniella N. Greenfield et al. Journal of Sexual Aggression, Volume 29, 2023 - Issue 1. Dec 22 2021. https://doi.org/10.1080/13552600.2021.2015469

Abstract: Emotional intelligence (EI) is defined by the ability to perceive, manage, and reason about emotions in oneself and others. Studies have reported deficits in EI abilities among certain antisocial populations such as individuals with psychopathy, and enhanced performance among sexual offenders. Despite EI's relevance to offending behaviour, the association between EI and paraphilic offending has been under-studied. We examined the association between EI, sexual offending, and sexual sadism in 80 incarcerated men with sexual offences and 207 incarcerated men with non-sexual offences. EI was assessed using the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). Sadism was measured using the Severe Sexual Sadism Scale (SeSaS). Results showed that SeSaS scores were positively associated with Strategic EI (the ability to understand and manage emotions), but were not significantly related to Experiential EI. This may reflect core characteristics of sexual sadism including domination and manipulation, challenging the prevalent notion that higher EI is invariably positive.

Practice impact statement: The study findings suggest that high EI may not always promote prosocial behaviour, which has significant implications for clinical practice. For example, treatment programmes aimed at generally improving EI-related abilities (e.g. emotion regulation) could be refined towards more specific or individualised strategies (e.g. how to effectively and prosocially use EI skills).

Sexual conflict can arise when males evolve traits that improve their mating success but in doing so harm females; by reducing female fitness, male harm can diminish offspring production in a population and even drive extinction

Male harm offsets the demographic benefits of good genes. Ewan O. Flintham, Vincent Savolainen, and Charles Mullon. Proceedings of the National Academy of Sciences, March 2, 2023, 120 (10) e2211668120. https://doi.org/10.1073/pnas.2211668120

Significance: Organisms vary in their biological condition. Those individuals in better condition show improved survival or fecundity, and so populations composed of such individuals should be more viable. However, high-condition individuals also express larger sexually selected phenotypes, some of which, in males, can harm females. The good genes hypothesis posits that sexual selection on condition-dependent traits indirectly increases mean condition and therefore population health. Here, using mathematical models, we show that this effect should rarely be expected when sexual traits cause harm: Instead, good genes selection leads to larger harming traits, reduced female fecundity, and potential population crashes.

Abstract: Sexual conflict can arise when males evolve traits that improve their mating success but in doing so harm females. By reducing female fitness, male harm can diminish offspring production in a population and even drive extinction. Current theory on harm is based on the assumption that an individual’s phenotype is solely determined by its genotype. But the expression of most sexually selected traits is also influenced by variation in biological condition (condition-dependent expression), such that individuals in better condition can express more extreme phenotypes. Here, we developed demographically explicit models of sexual conflict evolution where individuals vary in their condition. Because condition-dependent expression readily evolves for traits underlying sexual conflict, we show that conflict is more intense in populations where individuals are in better condition. Such intensified conflict reduces mean fitness and can thus generate a negative association between condition and population size. The impact of condition on demography is especially likely to be detrimental when the genetic basis of condition coevolves with sexual conflict. This occurs because sexual selection favors alleles that improve condition (the so-called good genes effect), producing feedback between condition and sexual conflict that drives the evolution of intense male harm. Our results indicate that in presence of male harm, the good genes effect in fact easily becomes detrimental to populations.

Discussion

Here, we have integrated key aspects from two groups of models: i) sexual conflict (e.g., refs. 18, 22–24, 27, 29) and ii) condition dependence (e.g., handicap models, 40–42, 48). In doing so, we have uncovered some surprising insights into how sexual selection shapes trait evolution and population demography.

Our analyses indicate that, like other sexually selected traits (30, 41, 42), male harm and female tolerance readily evolve condition dependence such that male and female investment into sexual conflict increases with condition. Populations in better condition thus experience more intense conflict, which impairs offspring recruitment and can jeopardize population persistence. In particular, if the severity of male harm increases more strongly with condition than does baseline female fecundity, we observe a counter-intuitive pattern whereby high mean condition is associated with low mean fitness. Such a negative association between condition and fitness is especially likely to emerge where condition has a genetic basis in males and females, as selection favors “good genes” that improve individual condition but also increase the intensity of male harm.

Our results contrast with the common view that sexual selection on good genes also improves mean fitness (43, 55, 65, 66) and mitigates the costs of sexual conflict (42). This is because for the good genes effect to work, that is, for sexual selection to increase mean condition, sexual traits must show appreciable condition-sensitivity (e.g. large κz in our model). In other words, sexual selection acts strongly on condition when good genes confer large increases in the size of sexual traits that males can afford to express. Therefore, the good genes effect is strong where a reduction in mutation load is associated with a significant increase in male sexual trait expression (e.g. in Figure 3A when κz = 1, an increase in condition, green points, is associated with a much larger increase in male trait size, blue points, see also figure 1a in (42)). Importantly, the repercussions of the good genes effect for male trait size are typically larger than for baseline female fecundity. This is because if condition genes greatly improve absolute baseline survival or fecundity, then natural selection should be intense enough to maintain them at relatively high frequency irrespective of the action of sexual selection (Figure 3C see difference between orange curves and black curve decreases with κα). The variation in genetic condition that is available for sexual selection to act upon is therefore limited, constraining the influence of the good genes effect on female fecundity relative to male trait expression. Altogether this means that, when male traits beget harm, the good genes effect has much greater scope to influence demography through sexual conflict than through baseline female fitness. Population benefits of good genes are thus easily reversed by their side-effect in exacerbating antagonistic male-female interactions.

In highlighting the relationship between condition and male harm, our results have implications for empirical work, in particular experimental evolution approaches to unpicking the consequences of sexual selection. Some studies have identified population-level benefits of sexual selection by tracking variation in condition (inferred through condition-correlated traits, e.g., body size, male mating success, offspring viability, or immune function) as a proxy of population viability (e.g., refs. 67–70 reviewed in ref. 71). Our results indicate such traits are poor indicators of population viability in species exhibiting male harm. Without measuring mean fitness, these studies therefore provide ambiguous evidence for an advantage to sexual selection. Indeed, when experimental studies do track more direct measures of mean fitness (such as female fecundity), they typically detect a weaker increase than for indirect measures such as body condition, mutation frequencies, or male mating success (71, 72). For example, a study in fruit flies found that sexual selection was associated with lower mutation load but also diminished offspring recruitment, which was attributed to the effects sexual conflict (73). Furthermore, a number of experimental studies have found evidence that sexual selection improves persistence in populations experiencing environmental stress (e.g., temperature variation in refs. 74–76, reviewed in refs. 77 and 43). This has been attributed to the idea that sexual and natural selection should be more closely aligned in such cases, i.e., that condition genes are more likely to benefit both sexual and nonsexual fitness when both sexes are poorly adapted (78–80). However, our analyses provide an additional explanation here: Environmental stress, by lowering male condition, may reduce the expression of male harm and so increase mean female fitness. More generally, we suggest that condition dependence provides a mechanism for the strength of sexual conflict to diverge in different environments a pattern, for example, observed in drosophila (81), and water striders (82).

To produce tractable results, our baseline model makes a number of simplifying assumptions. We assumed a well-mixed population (i.e., no effects of spatial subdivision); the absence of genetic constraints that affect condition- or sex-specific phenotypic expression; that males direct their mating attention indiscriminately toward high- and low-condition females; and that females express a tolerance trait that mitigates harm but does not impact male mating success. Relaxing these assumptions may alter the ecoevolutionary dynamics of sexual conflict through kin selection (27, 29), the strength of natural selection on females (70, 83), and the presence of coevolutionary intersexual arms races that escalate sexual conflict (24, 28, 84). Moreover, we considered two forms of condition variation, with condition either 1) a purely environmental trait or 2) purely genetic, while in nature, condition may frequently be an intermediate of these two scenarios (46). To relax some of these assumptions, in SI Appendix, Appendices C and D we also analyzed extended versions of our baseline model that allowed us to consider alternative bases of condition and multiple ecological settings for sexual conflict. In certain cases, such as where condition-dependent plasticity is prevented by genetic constraints, or where genotype × environment interactions depress male condition, we find that male harm can be diminished, so aiding population persistence (SI Appendix, Appendix D). However, our main results remain robust, that is, sexual conflict generates a negative relationship between average condition (e.g., good genes) and population size in the vast majority of the cases considered. In fact, we find that the costs of condition-dependent harm for population persistence may be strongly exacerbated in many common scenarios of sexual conflict, such as where female resistance drives evolutionary arms races, or where male and female conditions are encoded by different genes. We therefore suggest that the effects of condition variation found in our model will be general features found across most forms of sexual conflict (SI Appendix, Appendix D for a deeper discussion of extensions to our baseline model and of modeling choice and implications).

Finally, while our study was presented in the context of sexual conflict, our results are also more broadly applicable to the evolution of competitive traits with demographic effects. For example, antagonistic social interactions commonly drive the evolution of weapon phenotypes in both sexes (85, 86). These traits, which are often condition dependent, can influence the survival of interacting conspecifics (12, 13, 20, 33, 87, 88), and so their expression may also diminish mean fitness in high-condition populations.