Wednesday, June 30, 2021

While many behaviors emerge at similar ages in chimpanzees, human infants develop behavioral traits underpinning our prosocial and ultra-cooperative nature at a much accelerated rate

Becoming uniquely human? Comparing chimpanzee to human infancy. Tobias Grossmann. Developmental Science, June 28 2021.

Abstract: Does comparing behavioral development between chimpanzees and humans during infancy hold the key to understanding what is uniquely human? Recent work shows that while many behaviors emerge at similar ages in chimpanzees, human infants develop behavioral traits underpinning our prosocial and ultra-cooperative nature at a much accelerated rate.


laughing and comforting behaviors

Those of a left-wing orientation are more likely to use affiliative & aggressive humor styles; a general interest in politics is associated with the use of affiliative & self-enhancing styles of humor & a rejection of aggressive styles

The politics of being funny: Humor styles, trait humorousness, and political orientations. Marisa L. Kfrerer, Edward Bell, Julie Aitken Schermer. Personality and Individual Differences, Volume 182, November 2021, 111073.

Abstract: Previous research has shown that the use and appreciation of humor are related to various political phenomena. However, to date very little has been done to examine the association between specific styles of humor and left-right political orientations, the relationship between humor styles and political engagement, or the issue of whether political orientations predict the degree to which one has the ability to appreciate and create humor in everyday life. Data on humor styles, personality, and political attitudes gathered from an adult, community sample (N = 452; 70 men and 382 women) were analyzed to address this gap in the literature. The results indicate that people with a left-wing orientation are more likely to use affiliative and aggressive humor styles, that a general interest in politics is associated with the use of affiliative and self-enhancing styles of humor and a rejection of an aggressive humor style, and that those on the political left are not inherently more humorous than those on the right. These findings suggest that disparagement theories of humor may be more applicable to liberals and those less likely to take an interest in politics, and that an examination of how humor is used and perceived can broaden our understanding of left-right political differences and political participation.

Keywords: Humor stylesHumorPoliticsLeft-wingRight-wingLiberalConservativePolitical engagementPolitical participation

When a sexist statement is followed by a brief silence that disrupts the flow of the conversation, observers think that it is contentious and that sexism is neither shared nor normative

Koudenburg, N., Kannegieter, A. Postmes, T., Kashima, Y. (2020). The subtle spreading of sexist norms. Group Processes and Intergroup Relations, Oct 2020.

Abstract: Even when overt sexism and prejudice become rarer, social norms that perpetuate inequality are remarkably persistent. The present research lays out one of the subtle ways in which sexist norms may spread through society, by pointing to the role of responses to sexism. We investigate how third parties infer social norms about sexism when observing social interactions. In three studies among male students (Studies 1 and 2) and male and female students (Study 3), we demonstrate that subtle variations in how people respond to a sexist statement can have a substantial influence on inferences third parties make about sexist norms. Specifically, when a sexist statement is made and the conversation continues in a smoothly flowing fashion, third parties infer that this opinion is shared among interaction partners, perceived as appropriate, and that sexism is normative among them. However, when a sexist statement is followed by a brief silence that disrupts the flow of the conversation, observers think that it is contentious and that sexism is neither shared nor normative. Importantly, the effects of the manipulation generalized to the perception of sexist descriptive norms among male students in general. We conclude that social and cultural norms are not just inferred from conversation content, but also from conversational flow.

Many concerns have been raised about the perpetuation of social and cultural norms that promote inequality between social groups. The present research lays out one of the subtle ways in which sexist norms may spread through society, by pointing to the role of responses to sexism. Findings suggest that humans are very adept at interpreting social interactions, attending not just to what is said, but also to the subtle ways in which others respond. Even in the absence of explicit responses, sexist expressions are being evaluated by reference to the consensus that is inferred from the microdynamics of the conversational flow.

Across three studies, we demonstrated that subtle variations in conversational responses to a sexist statement influence the inference of sexist norms among passive observers. Specifically, when a sexist statement in a conversation (“Most women don’t have those natural leadership capacities”) was followed by the smooth continuation of the conversation, without objection to the statement, passive observers inferred that this opinion was socially accepted among interaction partners, and thus considered normative. Not only did observers feel this opinion was more shared among interaction partners (reflecting a descriptive norm shift, moderate to large effect), a meta-analysis across the three studies also suggests that participants feel the sexist statement is more appropriate to express in the conversation (reflecting an injunctive norm shift, moderate to large effect). Studies 2 and 3 demonstrated that the sexist norms inferred from a single conversation between male students were generalized to perceptions of increased endorsement of sexist ideas in the general population of male students.

The three studies further provide converging evidence on what could nullify the effect of a sexist statement on norm perception. In line with Hypothesis 2, when a sexist statement was followed by a brief silence that disrupted the flow of the conversation, observers were likely to take this as a sign that the statement was contentious and perceived the descriptive norm to be less sexist than in a conversation that continued as if nothing unusual had been said. Indeed, in the disrupted flow condition, the norm was seen to be no more sexist than in a control condition where no sexist statement was made. This demonstrates that brief disruptions of the flow of a conversation send a subtle but very powerful signal. Extending previous research that showed that speakers and observers experienced a relational threat after being exposed to a pause of less than 4 seconds in a 4-minute conversation (Koudenburg et al., 20112013b2014), the present research suggests that these relational inferences are intimately tied to the content of what is being discussed. As a result, conversational flow (or its disruption) can be a highly influential gauge of the degree of consensus within a group.

Study 3 further demonstrates that these inferences are not specific to male observers; female observers are just as likely to pay attention to conversational microdynamics when inferring sexist norms among male students. These findings point to the importance of subtle conversational cues in shaping social norms within specific groups and society in general.

Exploration of the effects on participants’ personal attitudes regarding sexism (Study 1) and their support for gender equality policies (Studies 2 and 3) revealed a somewhat different pattern. Here, we did not find a systematic effect of the responses to the sexist statement. The meta-analysis across studies, moreover, showed that observing a sexist statement, in itself, had only a small and marginally significant effect on sexist attitudes among participants. Thus, overall, there were medium to large effects on norms, and zero to small effects on attitudes. Similar effects have previously been found in within-group discussions about immigration, where strong normative shifts can occur without any corresponding attitude change (Smith & Postmes, 2011). This experimental evidence aligns with opinion polls, which show that despite substantial normative changes in the debate about, for instance, immigration in the US, attitudes on this topic have remained rather stable (e.g., Fussell, 2014). Norm perceptions, as our research confirms, are more subject to change, and important to study considering their influence on, for instance, people’s behaviour and voting (Ahler, 2014Miller et al., 2000).

The meta-analysis across studies suggests that a single instance of sexism that does not disrupt conversational flow can induce in observers the perception of sexism among the male student population in general. Apparently, inferences about perceived sexism from a small group discussion generalize to inferences about sexism in the wider population (although not to inferences about the appropriateness of such views among the population as a whole). Although we can only speculate about why descriptive population norms might be more affected than injunctive population norms, it could be that the current climate following the #metoo discussions provides many examples for people to imagine situations in which sexism may be inappropriate. The presence of an effect on the generalized descriptive norm, however, suggests that despite the obvious inappropriateness of these sexist views, observers still infer that male students may personally share them.

Whereas our previous research has focused on how flow disruptions signal disagreements, the present research reveals a potentially negative consequence of people’s natural tendency to preserve good and uninterrupted conversational flow. Oftentimes, people are motivated to maintain good relations even when they disagree with their conversation partner. When faced with a sexist expression, receivers may smoothly change topic to avoid further discussion of the sensitive issue, all the while preserving conversational flow. Interestingly, the present findings suggest that such behaviour may encourage the formation and maintenance of sexist norms. Indeed, in the absence of explicit information on receivers’ opinions on the issue, observers may infer that, in fact, the information is consensual and therefore grounded among conversation partners.

Social interactions that are observed by many people, such as those displayed on television, may be particularly influential in transmitting gender norms (Bandura, 2001Cialdini & Trost, 1998Signorielli, 1989) simply because they are observed by a large audience (Bandura, 2001Bryant & Zillmann, 1991). A substantial number of studies has documented the disproportionately high prevalence of gender stereotypic role models and sexist expressions on television (see Furnham & Paltzer, 2010, for a review). Although not much research has focused on the responses to such instances of sexism, the one study that did, documented very clear results: in many cases on prime-time television, bystanders did not respond (39% of the cases) or even responded positively to sexism (27% of the cases; Grauerholz & King, 1997). Without engaging with the consequences of the positive responses, the present research suggests that even the absence of responses could communicate social acceptance of sexist statements on prime-time television.

These findings are particularly interesting when considering that both victims and bystanders are often reluctant to confront sexism (for reviews, see Becker et al., 2014Drury & Kaiser, 2014). This reluctance is understandable given the consequences that such confrontation (vs. ignoring) may have for female victims, for instance in terms of liking (Dodd et al., 2001) or being viewed as oversensitive, interpersonally cold, or troublemakers (Czopp & Monteith, 2003Kutlaca et al., 2019). Although research suggests that confronting sexism may be less consequential for male bystanders (Gulker et al., 2013), their fear and stress of negative consequences—such as being disliked—often also lead them to refrain from confrontation (Kawakami et al., 2009). Whereas more research is needed before drawing conclusions about the role of microdynamics within all female, or mixed-gender conversations about sexism, our research is specifically engaged with the consequences of a lack of confrontation among these advantaged, male bystanders (see also Cihangir et al., 2014). In this group, the present study extends the insights into confronting discrimination in two ways: (a) it shows that a failure to confront may not just maintain the status quo, it may shift norms to become even more sexist, (b) but it also provides a relatively noncostly “tool” to prevent such change by communicating one’s disagreement with a brief conversational pause. Disrupting the flow can be a subtle, but quite effective way to signal that a sexist comment may threaten the relationship between speaker and listener, without having to engage in explicit confrontation (Koudenburg, 2018).

Variability in Infants' Functional Brain Network Connectivity Is Associated With Differences in Affect and Behavior

Variability in Infants' Functional Brain Network Connectivity Is Associated With Differences in Affect and Behavior. Caroline M. Kelsey, Katrina Farris and Tobias Grossmann. Front. Psychiatry, June 9 2021.

Abstract: Variability in functional brain network connectivity has been linked to individual differences in cognitive, affective, and behavioral traits in adults. However, little is known about the developmental origins of such brain-behavior correlations. The current study examined functional brain network connectivity and its link to behavioral temperament in typically developing newborn and 1-month-old infants (M [age] = 25 days; N = 75) using functional near-infrared spectroscopy (fNIRS). Specifically, we measured long-range connectivity between cortical regions approximating fronto-parietal, default mode, and homologous-interhemispheric networks. Our results show that connectivity in these functional brain networks varies across infants and maps onto individual differences in behavioral temperament. Specifically, connectivity in the fronto-parietal network was positively associated with regulation and orienting behaviors, whereas connectivity in the default mode network showed the opposite effect on these behaviors. Our analysis also revealed a significant positive association between the homologous-interhemispheric network and infants' negative affect. The current results suggest that variability in long-range intra-hemispheric and cross-hemispheric functional connectivity between frontal, parietal, and temporal cortex is associated with individual differences in affect and behavior. These findings shed new light on the brain origins of individual differences in early-emerging behavioral traits and thus represent a viable novel approach for investigating developmental trajectories in typical and atypical neurodevelopment.


The current study examined functional connectivity in brain networks using fNIRS and behavioral temperament using parental report in young infants. Our results show that functional connectivity in long-range cortical brain networks (FPN, DMN, and HIN) can be identified in very young infants and that functional connectivity in these networks varied considerably among infants. This supports the suitability of fNIRS in assessing functional connectivity and its variability in newborn infants. Importantly, our results also show that such variability in functional brain network connectivity systematically maps onto individual differences in infant behavioral temperament. Overall, the current findings provide novel insights into the brain origins of individual differences in affect and behavior, pointing to the early perinatal foundation of human temperament.

In line with our hypothesis, functional connectivity within the three brain networks (FPN, DMN, and HIN) was significantly greater than in the control network and significantly greater than a zero-value, indicating the existence of these long-range cortical brain networks in young infants. This provides further evidence that functional brain networks exist from early in ontogeny and are detectable in young infants (121771). To our knowledge, this is the first study to demonstrate long-range functional connectivity in FPN and DMN in young infants, suggesting a remarkably early emergence of long-range connectivity in higher-order brain networks linked to cognitive control and self-referential processes, respectively. The current findings are noteworthy also in regard to the fact that both networks involve regions in prefrontal cortex, providing new evidence from newborns and 1-month-old infants supporting the view that prefrontal cortex plays a critical role in human brain function from very early in development (147275).

In addition to the general difference in connectivity between the functional and the (non-functional) control network, we also found that activity in the FPN was significantly greater than in the DMN and HIN (whereas there was no difference in connectivity levels found between the DMN and HIN). One possible interpretation of this finding is that functional connectivity in the FPN might have been enhanced when compared to the other functional networks because, like other resting-state studies with infants, the participants were presented with a video accompanied by music during the fNIRS measurement (37). In other words, the FPN might have been more engaged because infants were attending to external audio-visual stimuli [note that all infants were exposed to the same video (audio-visual) stimulus]. Here, it is important to mention that prior work with adults using fMRI shows that functional connectivity in higher-order cortical resting-state networks can be reliably acquired during the presentation of videos and corresponds to functional connectivity acquired in the absence of any stimulus (476). Nonetheless, based on recent work showing that preterm infants display enhanced functional connectivity in higher-order cognitive networks in response to music (55), we speculate that enhanced functional connectivity in FPN might at least be partly explained by having newborn infants listen to music in the current study. Clearly, future research with infants which systematically compares stimulation protocols is needed to examine whether and how functional connectivity is influenced by the measurement context and the stimulation protocol used. Overall, our functional connectivity analysis supports the notion that intrinsic functional connectivity in cortical brain networks and its variability can be effectively mapped in newborn infants using fNIRS.

Having established functional connectivity in these brain networks as variable and distinct from a (non-functional) control network then allowed for the examination of specific associations between brain network connectivity and infant behavioral temperament. Our results confirmed our hypothesis and showed that infants' regulation/orienting behaviors were associated with functional connectivity in the FPN with greater connectivity in this network being associated with enhanced regulation and orienting. This result is in line with prior work linking functional connectivity in FPN to cognitive control of attention and behavior in adults (248) and more recent work with infants (43). The current results further showed the opposite pattern of association for functional connectivity in DMN, with greater connectivity associated with reduced regulation and orienting, which is in agreement with our hypothesis based on the DMN previously being linked to self-referential, stimulus-independent thought and mind-wandering in adults (248) and infants (43). To obtain such opposing effects of functional connectivity in FPN and DMN is reminiscent of seminal findings supporting the existence of anti-correlated brain networks in adults (77) and may suggest that similar organizational principles are at play in newborn infants. However, it should be emphasized that functional connectivity in the FPN and DMN in the current study was not anticorrelated as such, but rather had opposing effects on infants' behavioral and attentional regulation.

Our results concerning behavioral and attentional regulation and their functional connectivity correlates in infants are principally in line with prior research showing hyperconnectivity in the DMN and hypoconnectivity in the FPN in adults with negative emotionality and related mental health outcomes (333448). Moreover, our data show that infants' functional connectivity in the HIN was associated with negative emotionality. Contrary to prior work with adults indicating that hypoconnectivity is associated with negative emotionality and depression (333536) and work with infants indicating that corpus callosum length (thought to underly the HIN) is negatively associated with later emotion regulation abilities (45), the current infant data show that greater connectivity between homologous brain regions in both hemispheres was associated with greater negative affect. It is unclear why the direction of the association (positive vs. negative) would differ as a function of age (newborn infants in the current study and preschool aged and adults in previous work), but it is worth noting that the experience and display of negative affect only gradually emerges during infancy and may thus not be fully present in newborn infants (53).

Taken together, the current findings demonstrate specific associations between functional brain network connectivity and behavioral temperament in newborn infants. This suggests a remarkably early emergence of functional networks with behavioral relevance and highlights the importance of evaluating individual differences reflected in intrinsic brain connectivity. Although there are many advantages in the current approach of using fNIRS to examine functional brain connectivity, including its cost-effective and non-confining application, there are some limitations that need to be mentioned. First, because fNIRS is limited in monitoring activity from (superficial) cortical structures (78), our approach did not allow us to measure activity from deeper cortical and subcortical regions and include those in our network analyses. Second, from a developmental perspective, it should be noted that our analysis is limited to only one age group and comprised of very young infants. It is thus critically important to further assess the development of variability in these brain networks and their associations with behavioral temperament over developmental time to determine its long-term effects and the robustness of these associations (69). Third, it is important to note that these associations were assessed in a population of healthy infants, meaning there were no known birth or health complications at the time of the visit. Therefore, given the breadth of work examining how preterm birth and other medical complications (e.g., hypoxia) impact brain development, it will be important to test whether or not these associations generalize to other populations (167980).

In conclusion, the current study provides novel insights into the use of fNIRS in identifying neural endophenotypes—variability in functional brain network connectivity—linked to behavioral temperament traits in early human development. The present findings support the notion that functionally distinct neural networks are implicated in regulatory and emotional behaviors already in newborn infants, adding a critical developmental component to efforts directed at mapping how the individual functional connectome links to affective, cognitive, and behavioral traits. The current findings shed light on the brain origins of individual differences in early-emerging behavioral traits and provide the basis for future research examining the genetic and environmental factors contributing to and the long-term developmental consequences of this brain-behavior correlation. More generally, the current study provides early ontogenetic evidence for the idea that studying functional brain network connectivity is an effective way in helping bridge the gap between brain and behavior.

Less attractive & less intelligent-looking individuals seemed less human; attractiveness better predicted humanness attributions to women, perceived intelligence better predicted humanness attributions to men

Alaei, R., Deska, J. C., Hugenberg, K., & Rule, N. O. (2021). People attribute humanness to men and women differently based on their facial appearance. Journal of Personality and Social Psychology, Jun 2021.

Abstract: Recognizing others’ humanity is fundamental to how people think about and treat each other. People often ascribe greater humanness to groups that they socially value, but do they also systematically ascribe social value to different individuals? Here, we tested whether people (de)humanize individuals based on social traits inferred from their facial appearance, focusing on attractiveness and intelligence. Across five studies, less attractive and less intelligent-looking individuals seemed less human, but this varied by target gender: Attractiveness better predicted humanness attributions to women whereas perceived intelligence better predicted humanness attributions to men (Study 1). This difference seems to stem from gender stereotypes (preregistered Studies 2 and 3) and even extends to attributions of children’s humanness (preregistered Study 4). Moreover, this gender difference leads to biases in moral treatment that confer more value to the lives of attractive women and intelligent-looking men (preregistered Study 5). These data help to explain how interpersonal judgments of individuals interact with intergroup biases to promote gender-based discrimination, providing greater nuance to the mechanisms and outcomes of dehumanization. 

Gay men earned less than heterosexual men; gay women earned more than heterosexual women, while bisexual men earned less than heterosexual men; bisex women earned less than heterosexual women

Sexual Orientation and Earnings. A Meta-Analysis 2012-2020. Nick Drydakis. Global Labor Organization Discussion Paper No. 862. Jun 2021.

Abstract: This meta-analysis utilizes 24 papers published between 2012-2020 that focus on earnings differences by sexual orientation. The papers cover the period between 1991 and 2018, and countries in Europe, North America and Australia. The meta-analysis indicates that gay men earned less than heterosexual men. Lesbian women earned more than heterosexual women, while bisexual men earned less than heterosexual men. Bisexual women earned less than heterosexual women. According to the meta-analysis, in data sets after 2010, gay men and bisexual men and women continue to experience earnings penalties, while lesbian women continue to experience earnings premiums. Τhe meta-regression estimates indicate relationships between study characteristics and the estimated earnings effects for sexual minorities. For instance, regions, sexual minority data set sizes, and earnings classifications influence the outcomes. The persistence of earnings penalties for gay men and bisexual men and women in the face of anti-discrimination policies represents a cause for concern and indicates the need for comprehensive legislation and workplace guidelines to guarantee that people receive fair pay and not experience any form of workplace inequality simply because of their sexual orientation.

Considering narcissism and particularly psychopathy and sadism when investigating individual male preferences for outdoor sex services that are being offered by particularly vulnerable women

Darker Deals? Male Dark Tetrad preferences for female sex worker services. Sara Hughes, Joanna Adhikari, Katharine Goulding. Heliyon, June 24 2021, e07389.

Abstract: The present study explored links between male Dark Tetrad personality traits (psychopathy, Machiavellianism, narcissism, sadism) and preferences for using outdoor and indoor female sex worker services. We also investigated the mediating effects of perceiving sex workers as deviant and as victims. Heterosexual males ( N = 347) were recruited to take part in an online survey investigating personality and attitudes towards female sex workers. Path analyses revealed that psychopathy and sadism positively predicted preferences for outdoor but not indoor female sex services. Sex worker choice mediated positive links between narcissism and outdoor female sex worker preferences. Compared to indoor, outdoor sex services are associated with increased aggression and violence. Our findings highlight the importance of considering narcissism and particularly psychopathy and sadism when investigating individual male preferences for outdoor sex services that are being offered by particularly vulnerable women.

Keywords: Female sex servicesDark tetradPsychopathyNarcissismMachiavellianismSadism

4. Discussion

We explored links between male Dark Tetrad personality traits and outdoor/indoor female sex worker preferences, and the mediating effects of perceptions of sex worker choice and deviancy. Psychopathy and sadism positively predicted preferences for outdoor sex services only. It is perhaps not surprising that exploitative individuals with skills for identifying vulnerability reveal stronger preferences for particularly vulnerable women offering outdoor sex. Individuals high in psychopathy may prefer outdoor services for obtaining power (Kajonius et al., 2015 & Hare, 2006), and to achieve certain goals (Filipkowski & Derbis, 2020 & Hare, 1996), whereas opportunities to behave aggressively towards others may induce pleasure for sadistic individuals (Russell et al., 2017 & Lee, 2019). Such pleasure and successful goal achievements are less likely when using indoor sex services due to set rules and increased protection usually provided via third-party organisations.

Sex worker choice mediated positive relations between narcissism and preferences for outdoor sex services only. As narcissists exert increased efforts in impression management (Bastian, 2019 & Steinmetz et al., 2017), believing sex workers choose their profession may offer narcissistic justifications for using outdoor sex services. Perceiving sex workers as deviant mediated the negative relations between narcissism and psychopathy and indoor services. Relatedly, male perceptions of female deviance are a form of hostile sexism, referring to male preferences to maintain power over women. Women are perceived as deviant if they pose a threat to male dominance and power (de Zavala and Bierwiaczonek, 2020). As psychopathy and narcissism relate to increased desires for power and dominance (Waddell et al., 2020 & Hare, 1996), indoor sex workers may pose additional threats due to protection from third-party involvement. Whereas outdoor sex workers largely work in isolation. Future research could explore whether Dark Tetrad males perceive indoor sex workers as more deviant than outdoor sex workers.

Machiavellianism did however emerge as a non-significant predictor of preferences for outdoor and indoor sex services. Although Machiavellianism is commonly linked with exploitative mating strategies, these individuals demonstrate assortative mating preferences for social status and wealth when seeking short and long-term partners (Iná ncsi et al., 2016Marcinkowska et al., 2021 & Birkas et al., 2020). Status and wealth are external characteristics rarely associated with female sex workers. Furthermore, Machiavellian males report longer-term mating orientations, take fewer risks, and report higher levels of sexual disgust. (Burtaverde et al., 2021 & Karandikar et al., 2019), possibly resulting in reduced interests in engaging with either form of sex services. Additionally, Machiavellianism did not predict negative attitudes towards sex workers. Machiavellian males may therefore be less interested in using female sex services compared to fellow Dark Tetrad males.

Limitations and future research

Several limitations from our study should be addressed, however. First, we asked participants to rate their preferences for sex services, rather than obtain actual behavioural measures. Previous research has however reported positive relations between the original Dark Triad preferences and behavioural outcomes (Gott & Hetzel-Riggin, 2018). Second, we cannot infer causal conclusions due to the cross-sectional nature of our research, thus future research would benefit from using more objective behavioural methods. Finally, as 90% of our sample were aged between 18 and 38 years, we cannot really account for Dark Tetrad traits in older men who may reveal increased preferences for indoor services (Milrod & Monto, 2017) for companionship. Future research could address this as well as explore motivations behind preferences, including whether services are preferred for companionship or casual sex.

5. Conclusion

Overall, we contribute towards the existing literature on male Dark Tetrad personality traits by providing novel findings in relation to female sex worker services. Females who offer outdoor compared to indoor sex services report increased incidences of aggression and violence and are recognised as being particularly vulnerable to exploitative individuals who are adept at recognising vulnerability. Consequently, it is important to identify individual preferences for using outdoor sex services, so that awareness can be increased for these particularly vulnerable women. Our results highlight the importance of considering males high in Dark Tetrad narcissism and particularly sadism and psychopathy, who reported increased preferences for outdoor compared to indoor female sex worker services. We found no evidence linking Machiavellianism to either form of female sex worker preferences. As these findings are preliminary in nature, it would be beneficial for future research to determine the replicability of our results.

The finding that bisexuals are the sexual orientation group with the most pronounced Dark Triad profiles is opposite to what would be predicted by the prosociality hypothesis of same-sex sexual attraction

The dark side of the rainbow: Homosexuals and bisexuals have higher Dark Triad traits than heterosexuals. Peter K. Jonason, Severi Luoto. Personality and Individual Differences, Volume 181, October 2021, 111040.

Abstract: Research on the Dark Triad traits—psychopathy, Machiavellianism, and narcissism—reveals malevolent, transgressive, and self-centered aspects of personality. Little is known about the Dark Triad traits in individuals differing in sexual orientation, with some studies showing that non-heterosexual individuals have Dark Triad profiles resembling those of opposite-sex heterosexual individuals. In a cross-national sample (N = 4063; 1507 men, 2556 women; Mage = 24.78, SDage = 7.55; 90.58% heterosexual, 5.74% bisexual, 2.83% homosexual) collected online via student and snowball sampling, we found in sex-aggregated analyses that bisexuals and homosexuals were more Machiavellian than heterosexuals. Bisexuals were more psychopathic and narcissistic than heterosexuals. The only significant findings in within-sex comparisons showed that self-identified bisexual women scored higher on all Dark Triad traits than heterosexual women. The findings support the gender shift hypothesis of same-sex sexual attraction in bisexual women, but not in lesbians nor in men. The finding that bisexuals are the sexual orientation group with the most pronounced Dark Triad profiles is opposite to what would be predicted by the prosociality hypothesis of same-sex sexual attraction. The life history and minority stress implications of these findings are discussed as alternative hypotheses to the gender shift hypothesis.

Keywords: HomosexualityBisexualitySexual orientationDark TriadGender shift hypothesis

Donations of time are seen as more virtuous than donations of money, despite people’s (correct) belief that money-donations help more people; this is due to the perception that time-donors are more emotionally invested

Moral signaling through donations of money and time. Samuel G.B. Johnson, Seo Young Park. Organizational Behavior and Human Decision Processes, Volume 165, July 2021, Pages 183-196.


• Donations of time are seen as more virtuous than donations of money.

• This occurs despite people’s (correct) belief that money-donations help more people.

• The effect is driven by the perception that time-donors are more emotionally invested.

• These judgments influence interpersonal attraction and donor behavior.

• The findings support reputation-signaling accounts of prosocial behavior.


Prosocial acts typically take the form of time- or money-donations. Do third-parties differ in how they evaluate these different kinds of donations? Here, we show that people view time-donations as more morally praiseworthy and more diagnostic of moral character than money-donations, even when the resource investment is comparable. This moral preference occurs because people perceive time-donations as signaling greater emotional investment in the cause and therefore better moral character; this occurs despite the (correct) belief that time-donations are typically less effective than money-donations (Study 1). This effect in turn is explained by two mechanisms: People believe that time-donations are costlier even when their objective costs are equated, which happens because people rely on a lay theory associating time with the self (Study 2). The more signaling power of time-donations has downstream implications for interpersonal attractiveness in a dating context (Study 3A), employment decisions (Study 3B), and donor decision-making (Study 3). Moreover, donors who are prompted with an affiliation rather (versus dominance) goal are likelier to favor time-donations (Study 4). However, reframing money-donations in terms of time (e.g., donating a week’s salary) reduced and even reversed these effects (Study 5). These results support theories of prosociality that place reputation-signaling as a key motivator of moral behavior. We discuss implications for the charity market and for social movements, such as effective altruism, that seek to maximize the social benefit of altruistic acts.

Keywords: Prosocial behaviorAltruismMoral psychologyReputation signalingCharitable giving