Tuesday, June 1, 2021

Parallel to the reward system, the brain harbors an anti-reward system, which responds most vigorously to worst outcome among the available alternatives (disappointments, punishment)

Avoiding monetary loss: a human habenula functional MRI ultra-high field study. Kathrin Weidacker et al. Cortex, June 1 2021. https://doi.org/10.1016/j.cortex.2021.05.013

Abstract: A number of convergent human neuroimaging and animal studies suggest that habenula neurons fire in anticipation of non-rewarding outcomes, and suppress their firing in anticipation of rewarding outcomes. This normative function of the habenula appears disrupted in depression, and may be critical to the anti-depressant effects of ketamine. However, studying habenula functionality in humans using standard 3T MRI is inherently limited by its small size. We employed ultra-high field (7T) fMRI to investigate habenular activity in eighteen healthy volunteers during a Monetary Incentive Delay Task, focussing on loss avoidance, monetary loss and neutral events. We assessed neural activation in the field of view (FOV) in addition to ROI-based habenula-specific activity and generalized task-dependent functional connectivity. Whole FOV results indicated substantial neural differences between monetary loss and neutral outcomes, as well as between loss avoidance and neutral outcomes. Habenula-specific analyses bilateral deactivation during loss avoidance, compared to other outcomes. This first investigation into the habenula’s role during loss avoidance revealed that the left habenula further differentiated between loss avoidance and monetary loss. Functional connectivity between the right habenula and the ipsilateral hippocampus and subcallosal cingulate (regions implicated in memory and depression pathophysiology) was enhanced when anticipating potential losses compared to anticipating neutral outcomes. Our findings suggest that the human habenula responds most strongly to outcomes of loss avoidance when compared to neutral and monetary losses, suggesting a role for the habenula in both reward and aversive processing. This has critical relevance to understanding the pathophysiology of habenula function in mood and other neuropsychiatric disorders, as well as the mechanism of action of habenula-targeting antidepressants such as ketamine.

Keywords: habenulareward processingloss avoidancemonetary incentive delay taskfunctional connectivity

Fragile Heterosexuality: Previous research demonstrates that membership of majority groups is often perceived as more fragile than membership of minority groups

Fragile Heterosexuality. Keon West, Martha Lucia Borras-Guevara, Thomas Morton, and Katy Greenland. Social Psychology, Vol. 52, No. 3, May 31, 2021. https://doi.org/10.1027/1864-9335/a000444

Abstract. Previous research demonstrates that membership of majority groups is often perceived as more fragile than membership of minority groups. Four studies (N1 = 90, N2 = 247, N3 = 500, N4 = 1,176) investigated whether this was the case for heterosexual identity, relative to gay identity. Support for fragile heterosexuality was found using various methods: sexual orientation perceptions of a target who engaged in incongruent behavior, free-responses concerning behaviors required to change someone’s mind about a target’s sexual orientation, agreement with statements about men/women’s sexual orientation, and agreement with gender-neutral statements about sexual orientation. Neither participant nor target gender eliminated or reversed this effect. Additionally, we investigated multiple explanations (moderators) of the perceived difference in fragility between heterosexual identity and gay identity and found that higher estimates of the gay/lesbian population decreased the difference between the (higher) perceived fragility of heterosexual identity and the (lower) perceived fragility of gay identity.

General Discussion

This current research investigated whether there were asymmetrical fragility perceptions between heterosexual identity and gay identity. Specifically, and in line with previous results from different populations, we predicted that heterosexual identity would be perceived as more fragile than gay identity. We also investigated a range of possible moderators of this effect, including perceiver gender, target gender, attitudes, experiences, individual differences in intergroup orientations, and estimates of population size. It is important to note that the scale developed to measure the fragility of sexual orientation was reliable for Studies 3 and 4, which constitutes a further advance in trying to understand this phenomenon.

The results of all studies showed support for our central prediction: incongruous behaviors have a larger effect on perceptions of someone’s heterosexual identity than on perceptions of someone’s gay identity, hence heterosexual identity is more fragile (easily compromised) than gay identity. The findings were replicated across different methodologies; including perceptions of the sexual orientation of a target who engaged in behavior that contradicted his disclosed sexual orientation (Study 1), free-response indications of behaviors required to undermine the heterosexual and gay identities of both male and female targets (Studies 2a and 2b), agreement with statements related to male/female targets of different sexual orientations (Study 3), and agreement with gender-neutral statements about the fragility of heterosexual and gay identities (Study 4). The consistency of findings across samples and methodologies, provide strong evidence for the robustness of the effects found here, showing that it was not limited to a particular mode of response or type of stimulus. Regardless of how or with whom it was investigated, our participants consistently indicated a belief that heterosexual identity was more fragile than gay identity.

This is the first study to unequivocally demonstrate that the fragility of heterosexuality occurs for both men and women. Prior research either did not consider men and women separately (Duran et al., 2007Flanders & Hatfield, 2014) or failed to find the effect for women (Mize & Manago, 2018). We also show that the fragility effect persists even when behaviors under discussion are standardized across sexual orientations. Thus, our results add meaningfully to prior studies of asymmetrical perceptions of sexual orientations (Mize & Manago, 2018Duran et al., 2007Flanders & Hatfield, 2014) by establishing the reliability of this effect, with both men and women, in a different population, through larger samples, and with multiple divergent methods.

We also extend past research by testing different plausible moderators of this effect. In line with our predictions, higher estimates of the gay/lesbian population reduced the asymmetry in fragility perceptions between heterosexual identity and gay identity. It is also noteworthy that several other plausible variables – including anti-gay prejudice, contact with gay and lesbian individuals, and right-wing authoritarianism – did not moderate the fragile heterosexuality effect. Following the social normativity model (Monteith et al., 1996Zarate & Smith, 1990), disparities in summary information about a reference group (estimates of the gay/lesbian population), moderated the different fragility perceptions between heterosexual identity and gay identity. The results observed here show that when gay identity becomes less “deviant” and more prevalent within an individual’s perceptions of society, heterosexual and gay identities are perceived to be more similar in terms of fragility. These results may reflect an adjustment in status perceptions between groups. That is, people who perceive more widespread gay identities within their contexts also perceive a smaller gap between the status of heterosexual people and gay people.

Beyond the specific domain of sexual identities our results parallel with evidence from a variety of majority-minority distinctions that are asymmetrically perceived, including distinctions based on race and gender (Bosson & Vandello, 2011Duran et al., 2007Flanders & Hatfield, 2014Ho et al., 2013Khanna, 2010Vandello et al., 2008). For instance, the criteria for inclusion in racial categories typically differs between majority group membership (i.e., White) and minority group membership (i.e., Black). Reflecting a similar “one-drop rule,” studies have shown that the presence of a single Black ancestor can be sufficient for a person to be perceived as Black, but the presence of a single White ancestor is not sufficient for a person to be perceived as White (Ho et al., 2013Khanna, 2010). A similar pattern is evident in the context of gender identities. Research on precarious (fragile) manhood has shown that manhood is a status that is difficult to attain and maintain and can be easily lost through displays of un-manly behaviors. Womanhood, on the other hand, is a status that is ascribed rather than achieved, and is contingent on biological transformation rather than confirmation through one’s own behavior (Bosson & Vandello, 2011Bosson et al., 2009Vandello et al., 2008).

We acknowledge that the asymmetry in fragility between heterosexual identity and gay identity may be explained by an effect of cultural defaults on information diagnosticity. In other words, engaging in heterosexual behavior (e.g., visiting a non-sexual orientation coded bar) is not diagnostic of sexual orientation, but visiting a gay bar is, simply because it must be actively sought out among the myriad non-sexual orientation coded bar options. Relatedly, engaging in openly gay behavior may be considered more costly, as it comes with the potential for stigmatization. Thus, one might reasonably assume that even individuals who are gay might refrain from certain behaviors, making gay behavior more diagnostic.

However, if this were the case, the effect of fragile heterosexuality should have been moderated by participants’ levels of anti-gay bias, but this moderation was not significant. Also, were the fragile heterosexuality effect merely due to differences in assumed diagnosticity, we should not have found differences in the strength of the effect for men and women targets, which we did. Furthermore, the effect should have disappeared when we exclusively considered statements related to thoughts (supplementary analyses, see ESM 4). However, when we investigated this alternative explanation by excluding statements related to behavior from our fragility scale, we still found that heterosexual identity was perceived as more fragile than gay identity. These results strengthen our argument in support of the asymmetrical fragility perceptions between heterosexual and gay identities.

It should be noted that in spite of the higher fragility of heterosexual identity relative to gay identity observed across all studies and sub-groups, including men and women perceivers, the asymmetry in fragility perceptions between heterosexual identity and gay identity was larger for male compared to female targets (Study 3). These results could be attributed to women’s (actual or perceived) sexual fluidity. Several studies have concluded that women’s sexual orientation is significantly more dynamic than that of men (Diamond, 2000Kinnish et al., 2005). In fact, Kinnish and colleagues (2005) found that women, describe and experience their sexuality in continuous and ever-evolving terms, whereas men describe their sexual orientation as static and unchanging. Additionally, findings from Chandra et al. (2011) showed that the rate of men who identify themselves as bisexual was significantly lower compared to women. Accordingly, we believe that having less fluid sexuality (less gay/lesbian experiences) may be more indicative of men’s sexual orientation than it would be for women. To the extent that perceivers hold implicit theories of sexuality that are consistent with this picture, they are likely to judge male behavior as more diagnostic of sexual preferences than female behavior. Of course, it could equally be argued that just as heterosexual identity is more normative than gay identity, maleness is more normative than femaleness. Accordingly, the particular fragility of male heterosexual identity might reflect the intersection of these two categories.

The asymmetry in fragility perceptions between heterosexual and gay identities was quite robust, however, it is also the case that women participants generally perceived sexual categories to be less fragile than men participants did (Studies 3 and 4). This finding parallels findings from previous research on attitudes toward gay/lesbian people, in which women have been found to hold less negative attitudes toward gay/lesbian people compared to men (for a review see Whitley & Kite, 1995). Men are more likely to believe that gay identity is a discrete, dichotomous category, than women (Haslam & Levy, 2006), and are more likely than women to categorize themselves as “gay” based on past same-sex sexual experience (whereas for women, past experience does not automatically result in identification: Kinnish et al., 2005). Women seem to be less strict about defining the boundaries of sexual orientation to which they assign themselves (and others). The effects of perceiver gender might again reflect that women’s categorization processes are more flexible than those of men.

Limitations and Future Studies

The current research focused on asymmetrical fragility perceptions of heterosexual and gay identities. The concept of bisexuality or sexual fluidity was not explored. As this was the first representative quantitative exploration of fragile heterosexuality within a British population, this focus was necessary. However, perceptions of bisexuality and sexual fluidity are an important area of relevant future research. Some conceptions of bisexuality highlight the spectrum of possible gender identities and sexual attractions, undermining fundamental assumptions inherent in the definitions of both heterosexual and gay identities (Moore & Norris, 2005Peery & Bodenhausen, 2008Savin-Williams, 2016). Thus, future research on differences in perceptions of sexual orientation should explore a broader range of categories. For instance, participants could be given the option to assign a target to the bisexual or sexually fluid category. Relatedly, Peery and Bodenhausen (2008) found that the hypodescent effect for racial minorities decreases when participants have more time to categorize a target. Thus, a similar effect might occur for judgments of sexual orientation; participants may be more inclined to consider fluid sexuality or bisexuality when given more time to process a target’s behaviors.

Another consideration is that earlier studies have revealed a stereotype that gay people are more promiscuous than heterosexuals (e.g., Pinsof & Haselton, 2017). It is possible that the fragile heterosexuality effect found here may reflect this. That is, when gay people engage in incongruous sexual behavior, it may be more easily dismissed due to being understood as stereotype-consistent promiscuity and broadly directed sexual desire. Conversely, when heterosexual people engage in incongruous sexual behavior its observers tend to engage in more thorough processing of the implications for their sexual orientation. While this would not undermine the fragile heterosexuality effect, future research should investigate whether, and to what extent, the effect may be explained by relevant stereotypes of promiscuity concerning heterosexual people and sexual minorities.

Additionally, our study revealed that higher estimates of the gay/lesbian population lead to less differences in fragility perceptions between heterosexuals and gays. We suggest that these results may reflect participants’ change in status perceptions of these two groups. This contention should be tested empirically in future studies. For example, heterosexual participants could be primed with a scenario where the status of gay people is either more similar to or significantly different from the status of heterosexual people.

The studies reported here were carried out entirely in the UK using heterosexual, White, British participants. In spite of Britain being more open-minded and less prejudiced against sexual minorities than the USA (Mazzuca, 2004), our results parallel with those found for an American population (Mize & Manago, 2018). However, there is no evidence yet that the fragile heterosexuality effect transcends a particular Western cultural milieu. Indeed, as the effect appears to depend on estimates of gay/lesbian populations, it is reasonable to expect variation between nations based on the status of sexual minorities in each specific location. Future international and cross-cultural research would be important for exploring these hypotheses. Perhaps, exploring the differences between countries with a known-record of prejudice against sexual minorities, like Jamaica (Borras-Guevara & West, 2020West & Cowell, 2015) and a more egalitarian country like the UK. Targeted replications could also investigate whether sexual minorities also perceive heterosexual identity to be more fragile than gay identity.

Being perceived as a sexual minority implies being stereotyped and discriminated against, hence our focus was to understand where asymmetrical perceptions of the fragility of sexual orientation come from. However, we acknowledge that a very important step toward tackling prejudice against the LGBTQ community is to understand the consequences of these asymmetries too. Future research should study experimentally whether higher fragility leads to more negative attitudes/behaviors (e.g., violence) toward sexual minorities.

Can the Dunning-Kruger effect occur in the motor performance domain?

Can the Dunning-Kruger effect occur in the motor performance domain? Kell S. Tremayne, Glenn Newbery, Patsy Tremayne & Kenneth A. Nolan. International Journal of Sport and Exercise Psychology, May 27 2021. https://doi.org/10.1080/1612197X.2021.1929396

Abstract: The Dunning-Kruger effect is commonly understood as the tendency of relatively poor performers to grossly overestimate their ability and performance. This effect has been observed in a number of domains for which competence is wholly dependent on domain specific knowledge (e.g., the academic domain; the medical domain). However, it is claimed that the motor performance domain is not susceptible to the Dunning-Kruger effect because competence in this domain is dependent on factors other than knowledge (e.g., physical skill). The present study aims to test this claim. Eighty-three male participants performed one trial of the hand-grip strength task using their dominant hand. They also estimated their relative ability on the task, their relative performance on the task, and their score on the task. Participants were split into quartiles based on their actual task score. For each quartile, the mean estimated ability percentile and the mean estimated performance percentile were compared to the mean actual task score percentile. Also, mean estimated task score and mean actual task score were compared across quartiles. Consistent with the typical Dunning-Kruger effect, it was found that the worst performers were the most miscalibrated and significantly overestimated themselves, whereas the best performers significantly underestimated themselves. These findings indicate that the Dunning-Kruger effect can occur in the motor performance domain. They also cast doubt on the adequacy of the “metacognitive deficit” explanation, suggesting instead that, in the motor performance domain, motivational biases and defenses play a key role in the Dunning-Kruger effect.

KEYWORDS: Dunning-kruger effectmotor performancemetacognition

About 22% of Americans always (8%) or sometimes (14%) self-identify as “anti-vaxxers” (activists who support vaccine refusal), and that those who do tend to embrace the label as a form of social identity

Identifying the prevalence, correlates, and policy consequences of anti-vaccine social identity. Matt Motta, Timothy Callaghan, Steven Sylvester & Kristin Lunz-Trujillo. Politics, Groups, and Identities, May 30 2021. https://doi.org/10.1080/21565503.2021.1932528

Abstract: Scholarly and journalistic profiles of anti-vaxxers – i.e., individuals who are active in efforts to oppose widespread vaccination – suggest that some Americans may identify with the “anti-vaccine” label in order to fulfill social goals (e.g., a sense of belonging in a broader community). This is potentially problematic, as anti-vaxx social identification (AVSID) could imply increased receptivity to vaccine misinformation, and resistance to evidence-based medicine. In a large and demographically representative survey (N = 1001), we propose a novel measure of AVSID, and take stock of its prevalence and correlates. We find that about 22% of Americans always (8%) or sometimes (14%) self-identify as “anti-vaxxers” (activists who support vaccine refusal), and that those who do tend to embrace the label as a form of social identity. We also find that people who score highly on our AVSID measure tend to be less trusting of scientific experts and more individualistic. Finally, predictive validation analyses suggest that – among self-identified anti-vaxxers – AVSID is associated with increased opposition to childhood vaccine requirements. We conclude by outlining how our AVSID measure can be implemented to inform future research on opposition to evidence-based medicine and related public policies.

Keywords: Health opinionhealth policyvaccine opinionmisinformationsocial identification

From 2017... What factors are associated with reporting lacking interest in sex and how do these vary by gender? Findings from the third British national survey of sexual attitudes and lifestyles

From 2017... What factors are associated with reporting lacking interest in sex and how do these vary by gender? Findings from the third British national survey of sexual attitudes and lifestyles. Cynthia A Graham, Catherine H Mercer, Clare Tanton, Kyle G Jones, Anne M Johnson, Kaye Wellings, Kirstin R Mitchell. BMJ Open, Sep 2017. http://dx.doi.org/10.1136/bmjopen-2017-016942


Objectives To investigate factors associated with reporting lacking interest in sex and how these vary by gender.

Setting British general population.

Design Complex survey analyses of data collected for a cross-sectional probability sample survey, undertaken 2010–2012, specifically logistic regression to calculate age-adjusted OR (AOR) to identify associated factors.

Participants 4839 men and 6669 women aged 16–74 years who reported ≥1 sexual partner (opposite-sex or same-sex) in the past year for the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3).

Main outcome measure Lacking interest in sex for ≥3 months in the past year.

Results Overall, 15.0% (13.9–16.2) of men and 34.2% (32.8–35.5) of women reported lacking interest in sex. This was associated with age and physical and mental health for both men and women, including self-reported general health and current depression. Lacking interest in sex was more prevalent among men and women reporting sexually transmitted infection diagnoses (ever), non-volitional sex (ever) and holding sexual attitudes related to normative expectations about sex. Some gender similarities in associated relationship and family-related factors were evident, including partner having had sexual difficulties in the last year (men: AOR 1.41 (1.07–1.86); women: AOR 1.60 (1.32–1.94)), not feeling emotionally close to partner during sex (men: 3.74 (1.76–7.93); women: 4.80 (2.99–7.69) and ease of talking about sex (men: 1.53 (1.23–1.90);women: 2.06 (1.77–2.39)). Among women only, lack of interest in sex was higher among those in a relationship of >1 year in duration and those not sharing the same level of interest (4.57 (3.87–5.38)) or preferences (2.91 (2.22–3.83)) with a partner.

Conclusions Both gender similarities and differences were found in factors associated with lacking interest in sex, with the most marked differences in relation to some relationship variables. Findings highlight the need to assess, and if appropriate, treat lacking interest in sex in a holistic and relationship-specific way.


Regarding attitudinal variables, both men and women who endorsed statements that ‘people are under pressure to have sex’ and ‘people want less sex as they age’ were more likely to report lacking interest in sex over the past year. The only attitudinal variable that showed a significant interaction with gender was that which related to men having a ‘naturally higher sex drive than women’. Men who agreed with this statement were less likely than those who disagreed to lack interest in sex, while the reverse was true among women.


To our knowledge, no previous studies have assessed the association between attitudes towards sexual matters and lack of interest in sex. Endorsing the assumption that ‘people want less sex as they age’ was associated with lack of interest in both genders. It might be that this belief contributes to a decline in interest, or—equally plausible—that those who lack interest adopt this attitude to avoid viewing their experience as problematic. Interestingly, men who endorsed the view that ‘men have a higher sex drive than women’ were significantly less likely to report lacking interest in sex, whereas women who agreed with this statement were more likely to do so. If people responded to this statement with reference to their own relationship, these findings may be seen as making intuitive sense. The results suggest that endorsing stereotypical gender norms related to sex may adversely affect women more than men.

Individualism in market societies is often criticized as corrupting morality and discouraging charitable giving, but these authors disagree

Cai, Meina and Caskey, Greg and Cowen, Nick and Murtazashvili, Ilia and Murtazashvili, Jennifer Brick and Salahodjaev, Raufhon, Individualism, Economic Freedom, and Charitable Giving (May 28, 2021). SSRN: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3855820

Abstract: We investigate the role of individualistic social rules and norms in charitable giving. Individualism in market societies is often criticized as corrupting morality and discouraging charitable giving. We contest that view. We propose direct and indirect mechanisms through which that occurs. In the direct channel, individualism encourages self-interested giving. In the indirect channel, individualism contributes to charity by reinforcing economic freedom. We use evidence from a large cross-section of countries and several measures of individualism to investigate both channels. Our empirical findings confirm each channel and support the insights of classical liberals, such as Adam Smith and David Hume, and more recent studies in the humanomics tradition, which argues that there is virtue to individualism.

Keywords: Philanthropy, Culture, Individualism, Institutions, Classical Liberalism

JEL Classification: B52, D64, D31, L14

This paper investigates the role of individualism in charitable giving. Individualistic societies are those that value individual fulfillment, personal responsibility, and relationships with those outside one’s in-group. Though critics suggest individualism undermines virtues such as generosity, we consider contrary mechanisms first developed in the tradition of classical political economy, especially the “doux commerce” hypothesis (Hirschman 1982), which posits that self-interested pursuit of gains through trade has broader, usually positive, effects on the attitudes and behavior (Matson 2020). Originating in French Enlightenment–era works—especially Montesquieu (1777a, XX.2)—and later found in Mandeville (1988 [1714]), Smith (1982 [1759]), and Hume (1994 [1742]), these arguments fell out of favor within mainstream economics for much of the twentieth century (Boettke 1997). But interest in these works has reemerged alongside growing interest in endogenous preferences (Bowles 1998) and the cultural dimensions of economic activity and as experimental evidence identifying success in trade as a cause of prosocial conduct has accumulated (Smith and Wilson 2019).

[...] To test our hypotheses, we use evidence from a large cross-section of countries and several measures of individualism, including Hofstede’s (2001) individualism-collectivism index, the index of survival versus self-expression from the World Values Survey (WVS) (Inglehart and Oyserman 2004), and measures of generalized tolerance. Each represents a quantitative measure of culture, or what David Hume referred to as national character (Sent and Kroese 2020). Our empirical results show that individualism is indeed associated with charitable giving, as is economic freedom. The results support the argument of classical liberals thatcommercial society and the social and cultural institutions that support it are sources of the common good.

Colour Preferences and Personality: Blue and yellow was the most and least preferred; no gender differences; the blue group had higher scores on agreeableness & extraversion, & the red group had lower scores on agreeableness

Watten, R.G.; Fostervold, K.I. Colour Preferences and Personality Traits. Preprints 2021, 2021050642, doi 10.20944/preprints202105.0642.v1

Abstract: Colours are important features in human and natural environments and are related to several psychological functions. However, a possible relation between colour preferences and personality traits is scarcely investigated. The aim of the present study was to find out whether differences in preferences for colours also reflected differences in Big Five personality traits. The sample consisted of 206 individuals voluntarily recruited from a student sample. The participants chose one of six primary colours (blue, green, red, yellow, black, white) from the Natural Colour System (NCS) as their favorite colour. Personality traits were measured with the Big Five Inventory-44 (BFI-44. Blue and yellow was the most and least preferred chromatic colour, respectively. There were no gender differences in preferences for the chromatic colours, but more women preferred white and men preferred black. Compared to the rest of the sample, the blue group had higher scores on agreeableness and extraversion, and the red group had lower scores on agreeableness. Pairwise comparisons showed that the blue group had higher scores on agreeableness and extraversion than the red group, and higher scores on agreeableness compared to the green group. There were no significant personality differences for the other chromatic and achromatic colour groups.

Novels (n = 158) by lesbian authors showed minor signs of psycholinguistic masculinisation; novels (n = 167) by homosexual men had a female-typical psycholinguistic pattern

Sexual Dimorphism in Language, and the Gender Shift Hypothesis of Homosexuality. Severi Luoto. Front. Psychol., May 31 2021. https://doi.org/10.3389/fpsyg.2021.639887

Abstract: Psychological sex differences have been studied scientifically for more than a century, yet linguists still debate about the existence, magnitude, and causes of such differences in language use. Advances in psychology and cognitive neuroscience have shown the importance of sex and sexual orientation for various psychobehavioural traits, but the extent to which such differences manifest in language use is largely unexplored. Using computerised text analysis (Linguistic Inquiry and Word Count: LIWC 2015), this study found substantial psycholinguistic sexual dimorphism in a large corpus of English-language novels (n = 304) by heterosexual authors. The psycholinguistic sex differences largely aligned with known psychological sex differences, such as empathising–systemising, people–things orientation, and men’s more pronounced spatial cognitive styles and abilities. Furthermore, consistent with predictions from cognitive neuroscience, novels (n = 158) by lesbian authors showed minor signs of psycholinguistic masculinisation, while novels (n = 167) by homosexual men had a female-typical psycholinguistic pattern, supporting the gender shift hypothesis of homosexuality. The findings on this large corpus of 66.9 million words indicate how psychological group differences based on sex and sexual orientation manifest in language use in two centuries of literary art.


A corpus of 694 novels comprising 66.9 million words spanning more than two centuries of literary art was compiled to determine the extent to which heterosexual male and female authors, and homosexual male and female authors as well as a small sample of bisexual female authors, produced psycholinguistic outputs that differed in predictable ways. The results indicated significant sexual dimorphism6 in the language used in literary fiction written by heterosexual male and female authors, consistent with predictions based on cognitive neuroscience, psychology, and evolutionary science, while also providing support for the gender shift hypothesis of homosexuality (Abé et al., 2021Luoto et al., 2019aLuoto, 2020a). The gender shift hypothesis of homosexuality was strongly supported in homosexual males—who produced female-typical psycholinguistic outputs—whereas the evidence among homosexual female authors was substantially weaker, as they showed only a minor psycholinguistic shift in the heterosexual male direction.

While writers and readers, and speakers and listeners, have long been interested in how men and women may use language in slightly-to-vastly different ways, this study helps to clarify the existence, magnitude, and possible psychological underpinnings of sex differences in language use, which appear in areas over which writers would not be exercising sex-conscious psycholinguistic control. It would be difficult to conceive, for instance, how male authors might consciously increase the frequency with which they use articles (‘a,’ ‘an,’ and ‘the’) because they associate such language use with some nebulously “desirable” characteristics related to their ideas of “masculinity.” It is difficult, in other words, to explain the findings with the social role theory of gender roles, which would further struggle to provide a plausible explanation for homosexual male authors’ female-typical language use. If homosexual males were socialised into the male gender role, why do they use language in a way that resembles heterosexual women’s language use? To the extent that these findings represent non-conscious, natural ways of using language, they also suggest that homosexuality is not a conscious choice (Luoto et al., 2019aSwift-Gallant et al., 2019Bogaert and Skorska, 2020). It is highly unlikely, after all, that homosexual male authors have consciously chosen to write in a more female-typical way, of which they could have had limited notion at the level of psycholinguistic minutiae.

While some people argue that socialisation into gender roles underlies sex differences in humans, this hypothesis becomes implausible when considering the biological, developmental, neuroscientific, and cross-cultural evidence more broadly (Christov-Moore et al., 2014Schmitt, 2015Janicke et al., 2016Archer, 2019Del Giudice, 2019Luoto et al., 2019aAtari et al., 2020Stoet and Geary, 2020Luoto and Varella, 2021). Most sex differences in personality are of a higher magnitude in more gender-egalitarian countries than in less gender-egalitarian countries, which is the opposite of what the gender role hypothesis would predict (Schmitt et al., 2008Falk and Hermle, 2018Atari et al., 2020Stoet and Geary, 2020). Furthermore, since evolutionary processes pre-date social conceptualisations of gender roles by millions of years, a full explanation of socialisation into gender roles and the effects it has on sexually differentiated traits and behaviours would need to account for how evolutionary processes act as precursors to gender roles (Janicke et al., 2016Archer, 2019Luoto and Varella, 2021Luoto et al., 2021).

Ultimately, psychobehavioural sex differences arise from sexual selection, sexual differentiation of the mammalian brain, sexual division of labor, and their interactions (Figure 7) (Luoto and Varella, 2021). Sexual selection and sex differences in parental investment have exerted and currently exert selection pressures on status-striving and power-seeking among men more than in women (Luoto, 2019), contributing to men’s higher competition, aggression, risk-taking, sociosexuality, and men taking on more leadership positions than women, particularly at higher organisational and societal levels (Luoto and Varella, 2021). Sex differences in parental investment and mating competition coevolve with parental care specialisation, which can partially contribute to such psychobehavioural sex differences as found in empathising, people orientation, risk-taking, neuroticism, mate choice, sociosexuality, aggression, violence, leadership, and dominance (Archer, 2019Henshaw et al., 2019Luoto et al., 2019aLuoto and Varella, 2021). Sexually dimorphic ultimate evolutionary functions exert an influence on psychobehavioural sex differences via various biological mechanisms, leading to sexually dimorphic language use which, further down the evolutionary–developmental trajectory, also reflects other known psychobehavioural sex differences (Figure 7).


Figure 7. The evolutionary–developmental origins and proximate mechanisms underlying psychobehavioural sex differences, including those in language use. Figure adapted from Luoto and Varella (2021).

Comparative research provides further evidence against social role theories of human sex differences. Evidence of sex-biassed treatment by others (equivalent to what proponents of social constructionist hypotheses think of as socialisation into gender roles in humans) is lacking in non-human animals. Behaviours of mothers toward female and male offspring show little to no difference in the few species that have been studied (Lonsdorf, 2017), yet such species show sex differences in behavioural, physical, and social development that resemble those found in infant humans (Christov-Moore et al., 2014Lonsdorf, 2017Archer, 2019). These include sex differences in species-typical behaviours such as grooming, playing, object manipulation, and extractive foraging (Lonsdorf, 2017). Immature chimpanzee males, for instance, engaged in more object-oriented play than females (Koops et al., 2015). Under 5-week-old newborn rhesus macaque females that were raised in a controlled postnatal environment looked more at computer-generated faces of other rhesus macaques and engaged in more affiliative behaviour with a human caregiver than newborn rhesus macaque males did (Simpson et al., 2016). Similar findings have been reported in humans: 12-month-old female infants showed a higher relative preference for a moving face over a moving car than males did (d = −0.64) (Lutchmaya and Baron-Cohen, 2002). In humans, vervet monkeys, and rhesus macaques, females have been observed playing longer with dolls and plush toys, while males play longer with wheeled toys (Christov-Moore et al., 2014). Asian elephant females have a tendency to be more social and gregarious than males (Seltmann et al., 2019). In humans and non-human primates, females engage in social grooming more often than males (Lonsdorf, 2017). In hamsters and humans, females find same-sex social interactions more rewarding than males do. Oxytocin plays a similar mechanistic role in social reward processing in a number of species, suggesting that sociality and sex differences in sociality may arise from a common evolutionary origin (Feng et al., 2015Hung et al., 2017Borland et al., 2018).

Furthermore, evolutionarily conserved hormonal mechanisms, such as testosterone, are associated with language use and other sexually dimorphic phenotypes (Hoskin and Meldrum, 2018Mascaro et al., 2018Archer, 2019Luoto et al., 2019a), providing a biological basis for the emergence of sexually differentiated traits. Many lines of research, including longitudinal research in humans, support this theory. While hormone exposure significantly predicted gender development in girls, mothers’ socialisation to feminise the daughters had negligible effects: women exposed to more testosterone in prenatal development showed masculinised behaviours in adulthood despite parents’ socialisation efforts to have the daughters behave in a more feminine way (Udry, 2000).

Evidence for the relationship between testosterone and many sexually dimorphic phenotypes spans several different areas of research (Björkqvist, 2018Hoskin and Meldrum, 2018Luoto et al., 2019aMuñoz-Reyes et al., 2020). It is noteworthy that psychological research has not found reliably occurring differences in anger frequency; instead, sex differences have been found in verbal and physical aggression, both being higher in men (Archer, 2019). Thus, the slightly higher frequency of anger-related words in male authors’ novels (d = 0.32, Figure 1) does have some equivalents in psychological research. The use of anger-related words is positively correlated with circulating testosterone levels and with polymorphisms in the androgen receptor gene (Mascaro et al., 2018), which make cells more susceptible to the masculinising influence of testosterone. These findings indicate the existence of a plausible biological mechanism (Geniole et al., 2019Luoto et al., 2019a) which creates sex differences in anger-related language use as well as other psychobehavioural sex differences, including people–things orientation, risk-taking, and theory of mind (Khorashad et al., 2018Luoto, 2020bVaskinn et al., 2020Luoto and Varella, 2021). Furthermore, the finding of higher anger-related words and sexual words in lesbian authors relative to heterosexual women is consistent with existing findings on psychobehavioural masculinisation in non-heterosexual women, including higher sociosexuality, sensation-seeking, psychopathy, and incarceration rates compared with heterosexual women (Luoto et al., 2019a,b) (though see Gil-Llario et al., 2015 who reported lower sexual sensation seeking in self-identified lesbians than in heterosexual women).

An important contribution of this study was the ability to predict and explain sexual dimorphism in language using psychology and cognitive neuroscience. A related major result is that prior research on sex differences and sexual orientation differences in these fields have clear equivalents in the psycholinguistic outputs of authors writing literary fiction decades and centuries ago, suggesting that psychological sex differences may be relatively stable across time and across different domains—that is, they manifest not only via questionnaires, psychological tests, and behavioural measures, but also in the artistic and linguistic forms of imaginary self-expression enabled by literary fiction; and they manifest not only in contemporary population-based samples, but also in the highly specialised sample of writers of canonical literary fiction from decades and centuries ago. This coherence across different areas of research and across different time periods allays concerns that could be raised about the generalisability of the current findings.


A clear limitation of this study was that the analyses were conducted only on English-language material. Future studies are therefore encouraged in other languages to provide an estimate of the generalisability of these findings across other languages. Corresponding results have, however, been reported in a number of languages using various literary and non-literary sources, though few studies have distinguished between writers of different sexual orientations (cf. Argamon et al., 2009Johannsen et al., 2015Chen et al., 2018Koolen, 2018).

Another potential limitation of this study is that effect sizes can become biassed because of range restriction, which refers to a process in which the participants of a study are, directly or indirectly, selected from the original population on the basis of their personal characteristics (Del Giudice, 2019). In the current case, all samples of novels are likely to suffer from range restrictions as the novels were not sampled at random from all novels ever written by heterosexual or homosexual men and women; rather, canonical and prizewinning novels were mostly used, although the non-heterosexual samples also included less well-known novels because of the necessity to reach a large enough sample size. What is more, it may not be possible to directly extrapolate these findings on novelists to the respective groups of all lesbian women or all gay men or all heterosexual women and men. That is because only a small subset of each of these groups is likely to write and publish novels, particularly novels that reach a canonical status; thus, the sampling of such individuals may not be generalisable to the full sample of non-novelists in each group. This limitation can be addressed by comparing the present findings with existing findings on similar group differences that have been acquired using other kinds of methodologies and sampling protocols on non-novelists. Thus, to the extent that the current findings are consistent with the findings of other sex difference and sexual orientation difference studies (which they generally tended to be), the sampling problem of focussing only on novelists is mitigated.

This study was also limited in the sense that the heterosexual sample was drawn from canonical and prize-winning authors’ works: these culturally esteemed works may not generalise to the other 99% of literature ever written (Moretti, 20052013). Furthermore, as most of the non-heterosexual sample comprised works that were not canonical nor prize-winning (necessarily so because of the difficulty of obtaining such samples that would have been large enough for adequate statistical power), I cannot rule out the possibility that the psycholinguistic differences observed in this study between authors of different sexual orientation could have been partially driven by the differences in canonicity and/or literary prestige between the samples. Nevertheless, the likelihood of this possibility is somewhat attenuated as the findings largely aligned with predictions which arose from existing psychological and linguistic research as well as theory from evolutionary human science. To explain the findings as resulting from differences in canonicity, it would be necessary to posit how the sampling strategy used for homosexual male and female authors biassed language use in opposite directions in each sample in a manner which is consistent with the theoretical hypotheses and predictions. Although the non-heterosexual samples comprised novels that were published much more recently than the novels in the heterosexual samples, those differences in publication year were controlled for in all analyses. Correlations between publication year and all psycholinguistic outcome variables are available in the Supplementary Materials, as are correlations between authors’ age at publication and all the psycholinguistic outcome variables (Supplementary Tables 81011).

The group differences reported in the study could be somewhat attenuated because of the diversity of author demographics included in the samples of novelists. For example, authors were sampled from more than five countries. Authors’ age in the heterosexual sample of 304 novels varied from 24 to 68, while year of publication varied from 1801 to 2017 (Luoto and van Cranenburgh, 2021). Likewise, although the sample comprised mainly Caucasian authors, the full sample included authors whose racial backgrounds were Latino, African–American, Asian, Native American, and mixed (see Supplementary Tables 2–6 for details). Though making the sample more representative of the respective authors’ populations, this sample diversity may have caused more variation in the psycholinguistic outcome variables than studying more homogenous author populations, and this higher variation could have resulted in smaller effect sizes (as in Newman et al., 2008). Thus, the effect sizes reported in this study could be underestimates, and having less variation in publication year, age, race, ethnicity, and nationality can lead to detecting larger effect sizes.

The authors’ sexual orientation was determined based on biographical information, including information on the sex of any partners (married or otherwise) that the authors had or any self-identification related to sexual orientation that the authors may have made publicly known (Luoto and van Cranenburgh, 2021). The authors’ sexual orientation for the purposes of this study is therefore based on both manifest sexual behaviour as well as self-identification; however, both sexual behaviour and sexual orientation may undergo various changes over time, especially in non-heterosexual women (Luoto et al., 2019a,b), which is why the use of an aggregate measure of lifetime sexual behaviour and sexual orientation may not accurately track a person’s sexual behaviour or sexual orientation at any single point in time. Sexual orientation is used in this study as an instructive overall indicator of an author’s sexual behaviour and attractions over their lifetimes, and as such may be limited by the availability of such information in biographical material (Luoto and van Cranenburgh, 2021).

One reason why the gender shift hypothesis was not strongly supported in homosexual female authors could have been because it was not possible to control for butch/femme differences in the sampled authors. This would have been an important addition to the study. After all, there can be significant variation in the masculinity/femininity of non-heterosexual women, and research on non-heterosexual women should take this variation, conceptualised, e.g., via butch/femme categories, into account by analysing different groups of non-heterosexual women separately (Luoto et al., 2019a,b). However, in this research on literary fiction, it would have been difficult (if not impossible) to study women’s self-identification as masculine butches or feminine femmes because many of the authors had passed away.

Attitudes toward life extension: Men indicated a higher level of willingness to use the life extension treatment; younger-old and older-old adults indicated that they would prefer to live permanently at an older age

Who wants to live forever? Age cohort differences in attitudes toward life extension. Michael D. Barnett, Jessica H. Helphrey. Journal of Aging Studies, Volume 57, June 2021, 100931. https://doi.org/10.1016/j.jaging.2021.100931


• Investigated attitudes toward life extension about young adults, younger-old adults, and older-old adults.

• Age cohorts did not vary in their willingness to use life extension; however, in all three age cohorts, a plurality indicated that they would not use it.

• Men indicated a higher level of willingness to use the life extension treatment than women.

• Younger-old and older-old adults indicated that they would prefer to live permanently at an older age than young adults.


Introduction: Biomedical technology holds the promise of extending human life spans; however, little research has explored attitudes toward life extension.

Methods: This survey asked young adults (n = 593), younger-old adults (n = 272), and older-old adults (n = 46) whether they would take a hypothetical life extension treatment as well as the youngest and oldest age at which they would wish to live forever.

Results: Age cohorts did not vary in their willingness to use life extension; however, in all three age cohorts, a plurality indicated that they would not use it. Men indicated a higher level of willingness to use the life extension treatment than women. Younger-old and older-old adults indicated that they would prefer to live permanently at an older age than younger adults.

Discussion: If a life extension treatment were to become available that effectively stopped aging, young adults may be likely to use such a treatment to avoid reaching the ages at which older cohorts say they would prefer to live forever.

Keywords: Aging attitudesTechnologyImmortality

Intelligence can be detected but is not found attractive in videos and live interactions; more intelligent people were perceived as more intelligent, but not as funnier

Intelligence can be detected but is not found attractive in videos and live interactions. Julie C. Driebe et al. Evolution and Human Behavior, May 31 2021. https://doi.org/10.1016/j.evolhumbehav.2021.05.002

Abstract: Self-reported mate preferences suggest intelligence is valued across cultures, consistent with the idea that human intelligence evolved as a sexually selected trait. The validity of self-reports has been questioned though, so it remains unclear whether objectively assessed intelligence is indeed attractive. In Study 1, 88 target men had their intelligence measured and based on short video clips were rated on intelligence, funniness, physical attractiveness and mate appeal by 179 women. In Study 2 (N = 763), participants took part in 2 to 5 speed-dating sessions in which their intelligence was measured and they rated each other's intelligence, funniness, and mate appeal. Measured intelligence did not predict increased mate appeal in either study, whereas perceived intelligence and funniness did. More intelligent people were perceived as more intelligent, but not as funnier. Results suggest that intelligence is not important for initial attraction, which raises doubts concerning the sexual selection theory of intelligence.

Keywords: IntelligenceMate choiceSexual selection