Environmental harshness and unpredictability, life history, and social and academic behavior of adolescents in nine countries

Chang, L., Lu, H. J., Lansford, J. E., Skinner, A. T., Bornstein, M. H., Steinberg, L., Dodge, K. A., Chen, B. B., Tian, Q., Bacchini, D., Deater-Deckard, K., Pastorelli, C., Alampay, L. P., Sorbring, E., Al-Hassan, S. M., Oburu, P., Malone, P. S., Di Giunta, L., Tirado, L. M. U., & Tapanya, S. (2019). Environmental harshness and unpredictability, life history, and social and academic behavior of adolescents in nine countries. Developmental Psychology, 55(4), 890–903. https://doi.org/10.1037/dev0000655

Abstract: Safety is essential for life. To survive, humans and other animals have developed sets of psychological and physiological adaptations known as life history (LH) tradeoff strategies in response to various safety constraints. Evolutionarily selected LH strategies in turn regulate development and behavior to optimize survival under prevailing safety conditions. The present study tested LH hypotheses concerning safety based on a 6-year longitudinal sample of 1,245 adolescents and their parents from 9 countries. The results revealed that, invariant across countries, environmental harshness, and unpredictability (lack of safety) was negatively associated with slow LH behavioral profile, measured 2 years later, and slow LH behavioral profile was negatively and positively associated with externalizing behavior and academic performance, respectively, as measured an additional 2 years later. These results support the evolutionary conception that human development responds to environmental safety cues through LH regulation of social and learning behaviors.

Keywords: fast and slow life history strategy; environmental harshness; unpredictability; externalizing; academic performance; child and adolescent development

It seems impulsivity doesn't evolve in response to childhood environmental harshness

Can impulsivity evolve in response to childhood environmental harshness? Atsushi Kometani, Yohsuke Ohtsubo. Evolutionary Human Sciences, Volume 4, May 24 2022, e21. DOI: https://doi.org/10.1017/ehs.2022.22

Abstract: Previous studies have suggested that human impulsivity is an adaptive response to childhood environmental harshness: individuals from families of low socioeconomic status (SES) tend to be more impulsive. However, no studies have tested the evolvability of this reaction norm. This study examined whether (a) impulsivity is associated with higher fitness among individuals from low SES families, while (b) it is associated with lower fitness among individuals from high SES families. We assessed three indices of impulsivity (temporal discounting, risk taking and fast/slow life history strategy), childhood SES and five proxy indices of fitness (number of children, lifelong singlehood, annual household income, subjective SES and life satisfaction) of 692 middle-aged participants (40–45 years old). None of the results supported the evolvability of the impulsivity reaction norm, although low childhood SES was associated with lower fitness on every proxy measure. Impulsivity (operationalised as the fast life history strategy) was associated with lower fitness regardless of childhood SES.

Discussion

We examined the evolvability of the impulsivity reaction norm. Although the results confirmed the basic presumption that childhood economic harshness adversely influenced participants’ later fitness, none of the other results supported the impulsivity reaction norm's evolvability: when operationalised as risk-taking tendency, impulsivity was associated with higher fitness among individuals with high, but not low, childhood SES (this pattern, however, was not replicated in our subsequent unpublished study including only male participants). When operationalised by Mini-K score, it was associated with lower fitness regardless of childhood SES.

The present study failed to replicate the results of previous studies (Griskevicius et al., Reference Griskevicius, Ackerman, Cantú, Delton, Robertson, Simpson and Tybur2013). In particular, childhood SES was not significantly associated with either risk taking or temporal discounting. Given the robust association between childhood SES and BCD (Pepper & Nettle, Reference Pepper and Nettle2017), the present study's operationalisation of impulsivity might have provided inadequate indices of impulsivity. For example, one could argue that the temporal discounting and risk-taking tasks should have been incentivised (but see Amir et al., Reference Amir, Jordan and Rand2018, which reported no systematic differences between incentivised and non-incentivised risk-taking tasks). Mishra et al. (Reference Mishra, Barclay and Sparks2017) recently proposed a model of risk-taking (relative state model) that distinguishes two types of risk-taking behaviours, need-based and ability-based risk-taking; the former is motivated by poor environments, while the latter is motivated by superior abilities (i.e. the prospect of successful risk-taking). In future studies, it is worthwhile not only to incentivise risk-taking tasks but also to distinguish subtypes of risk-taking and impulsivity based on such a nuanced model.

One limitation is that we assessed fitness in a modern, industrialised society that is largely different from the environment of evolutionary adaptedness (EEA). For example, if low SES conditions in contemporary Japan are still more benign compared with harsh conditions in EEA, the present study may not be a fair test of the hypothesised phenotypic plasticity. Nonetheless, it is worth noting that childhood SES was in fact positively associated with every measure of fitness in this study. Moreover, careful analyses revealed some comparability of the modern and ancestral environments (i.e. positive association between wealth and the number of children in both modern and ancestral environments; Nettle & Pollet, Reference Nettle and Pollet2008). Nevertheless, this particular result does not necessarily imply that the comparability between the modern and ancestral environments extends to other aspects. For example, one could argue that impulsivity is an effective strategy for disadvantaged individuals only in EEA but not in the modern environment. Since there is a wide range of differences between the modern environment and EEA, or the so-called evolutionary mismatch problem (Li et al., Reference Li, van Vugt and Colarelli2018), it is informative to replicate this study in populations that maintain traditional lifestyles.

We admit that this study does not disprove the evolvability of human reaction norms as a whole. This study only tested the evolvability of impulsivity in response to childhood economic harshness. There are other independent and dependent variables that have attracted researchers’ attention in the context of life history theory in psychology. For example, timing of puberty and parental strategies are oft-studied life history traits (i.e. dependent variables), and childhood mortality/morbidity and unpredictability are oft-studied environmental (independent) variables (Ellis et al., Reference Ellis, Figueredo, Brumbach and Schlomer2009). Therefore, future studies need to include a wider range of measures of childhood environments and life history traits in order to fully test the evolvability of any form of phenotypic plasticity in response to early environments.

In summary, this study does not reveal any evidence of the evolvability of the impulsivity reaction norm in response to childhood economic harshness. Therefore, we urge researchers to critically assess the impulsivity reaction norm, especially whether the adaptationist explanation is better supported by empirical data than by-product explanations.

Global sex differences in hygiene norms and their relation to sex equality

Global sex differences in hygiene norms and their relation to sex equality. Kimmo Eriksson,Thomas E. Dickins, Pontus Strimling. PLOS Glob Public Health 2(6): e0000591. June 21, 2022. https://doi.org/10.1371/journal.pgph.0000591

Abstract: Strict norms about hygiene may sometimes have health benefits but may also be a burden. Based on research in the United States, it has been suggested that women traditionally shoulder responsibility for hygiene standards and therefore tend to have stricter views on hygiene. However, there is little systematic research on sex differences in hygiene norms at the global scale. We set up two hypotheses: (1) Stricter hygiene norms among women than among men is a global phenomenon. (2) The size of this sex difference varies across nations with the level of sex equality. We examine these hypotheses using data from a recent international survey (N = 17,632). Participants in 56 countries were asked for their views of where it is not appropriate for people to spit and in which situations people should wash their hands. As a measure of sex equality, we use an existing country-level measure of attitudes to equality between the sexes, available for 49 nations in the study. Stricter hygiene norms among women than among men are observed almost everywhere, but there are a few exceptions (most notably Nigeria and Saudi Arabia). The size of the sex difference in hygiene norms varies strongly with the level of sex equality, but in a non-linear way. The sex difference is most pronounced in moderately egalitarian countries with the highest recorded difference being in Chile. In more egalitarian parts of the world, more sex equality is associated with a smaller sex difference in hygiene norms. In the less egalitarian parts of the world, the opposite relation holds. We offer an interpretation in terms of what different levels of sex equality mean for the content of sex roles.

Discussion

Using data in 56 countries, the current study provided a comprehensive analysis of the sex difference in hygiene strictness. We studied a set of norms about when you should wash your hands and where you should not spit. Globally, we found norms about handwashing to be slightly stricter among women than among men. The direction of this sex difference is consistent with findings in many single-country behavioral studies of handwashing [11–15]. We found even more substantial sex differences in the strictness of spitting norms. This is an important novel finding as no prior studies have examined sex differences in spitting. Perhaps it is related to men producing more saliva than women do [31], as this might create a stronger preference in favor of spitting. It is possible that spitting elicits a stronger disgust response in women by association because spitting is an innate behavioral response to remove noxious material from the mouth [32]. But there are also differences in the types of norms the two behaviors are involved in. For one thing, handwashing norms are prescriptive while norms about spitting are proscriptive. For another, handwashing is primarily a private good while strictness about spitting is primarily a public good. Moreover, the handwashing norms we studied were concerned with when you should wash your hands whereas the spitting norms were concerned with where you should not spit. This could play a role as culture may restrict women’s access to certain locations (e.g., soccer pitches). Future work may examine the specific roles of these factors.

Our first hypothesis was that the sex difference in hygiene strictness would be observed everywhere. In our dataset, we observed the sex difference in most countries but not all. Two countries, Saudi Arabia and Nigeria, were clear exceptions in that men reported stricter hygiene norms than women. To validate this finding, we searched for prior studies of hygiene in any of these countries that report results separately for men and women. We found two such studies for Saudi Arabia, both of which indeed reported stricter hygiene among men than among women [33, 34]. Thus, our findings are consistent with prior literature. We conclude that sex difference in hygiene strictness is nearly universal but that the presence of clear exceptions demonstrates that there is some cultural moderator that needs to be understood.

Our second hypothesis examined a proposed cultural moderator: the level of sex equality in society. We operationalized societal sex equality by the average attitude to sex equality with respect to participation in the job market, in politics, and in higher education. Such attitudes can be taken as a proxy for the strength, or weakness, of sex roles. Some authors have attributed stricter hygiene norms among women to sex roles [2, 21]. However, a more complex picture emerged in our data. The sex difference in hygiene strictness was often larger in countries with above-average levels of sex equality than in countries with below-average levels of sex equality. This finding is in keeping with many behavioral and somatic sex difference results and Schmitt has argued that biological sex differences can be moderated and facilitated by specific cultural contexts [16]. To our knowledge it has not be shown for the contents of normative beliefs. Within these groups of countries, the sex difference in hygiene strictness varied with the level of sex equality in different ways. Among countries with above-average sex equality, the sex difference in handwashing strictness showed no relation with sex equality whereas the sex difference in spitting strictness showed a negative relation with sex equality. Thus, the hypothesis was partially supported in this group of countries. Results looked very different in the group of countries with below-average levels of sex equality. In this group, the expected sex difference was most pronounced at the high end of sex equality, that is, at global average levels of sex equality. In countries with greater inequality, the sex difference in hygiene strictness disappeared and even became reversed at extreme levels of inequality (Saudi Arabia and Nigeria). This reversal suggests a flexible connection, if any, between hygiene norms and established sex differences in disgust sensitivity. But it is possible that the underlying asymmetry in inclusive fitness costs is something that can drive either male or female custodianship of hygiene, and hence difference in hygiene strictness, dependent upon key social ecological factors. Our analyses strongly supported that sex equality is a key factor. Specifically, while prior research has found that pathogen prevalence and religiosity may be more important factors behind sex differences in other domains [16], we found the level of sex equality do be a much stronger predictor of sex differences in hygiene.

In sum, we have found that there is substantial cultural variability in the extent to which women have stricter hygiene norms than men do, and it is quite strongly related to sex equality—but in a non-linear way. A possible interpretation of this unexpected finding is that the full spectrum of sex inequality encompasses several distinct phenomena. If we hold on to the notion that the sex difference is due to sex roles giving women a greater responsibility for maintaining hygiene in society, how could this responsibility vary across different levels of gender inequality? In moderately unequal societies, both women and men are fully responsible, but they tend to have different responsibilities. Women and men are seen as working together in a family unit where she is responsible for raising the children and keeping the home clean while he is responsible for bringing home most of the income. It is in these societies we would expect women to be more responsible for hygiene. As societies become more egalitarian, these sex roles weaken, and we would expect a decline in the sex difference in hygiene. In the most unequal societies, however, it is arguably men that have the responsibility in that they make decisions about the whole family’s behavior and are held responsible for the behavior of their wives or daughters. As a case in point, all women in the extremely unequal society of Saudi Arabia have a legal male guardian who is responsible for them [35]. Among other things, this ultra-low level of women’s responsibility means a lower level of responsibility for hygiene. Sex segregation in Saudi Arabia also implies that women are allowed less mobility and thereby potentially less exposure to situations and things that may motivate hygiene norms, in this way moderating any underlying biological sex differences [16]. This could be examined in future research.

Limitations

Limitations of the data were discussed by Eriksson et al. [8]. Most importantly, as the data are limited to hand washing and spitting norms, we cannot say whether the sex difference in hygiene strictness generalizes to other hygiene-related behaviors, such as washing the whole body, washing clothes, coughing, sneezing, and urinating. Other limitations include that African countries and small countries were undersampled, that socioeconomic stratification within countries is not measured, and that samples per country are sometimes quite small and not necessarily representative. However, these may not be major concerns, as prior analyses of data from these samples successfully replicate country-level variation in cultural values found in representative samples [22, 36]. Another limitation is that we do not have data on participants’ knowledge of objective benefits of hygiene.

Dominance judgments—important across numerous psychological domains, like attractiveness, leadership, & legal decision-making—accurately predict the likelihood with which a potential mate, ally, or rival can incapacitate their adversaries

Caton, Neil R., Lachlan M. Brown, Amy Zhao, and Barnaby Dixson. 2022. “Human Male Body Size Predicts Increased Knockout Power, Which Is Accurately Tracked by Conspecific Judgments of Male Dominance.” PsyArXiv. June 29. doi:10.31234/osf.io/3jny4

Abstract: Humans have undergone a long evolutionary history of violent agonistic exchanges, which would have placed selective pressures on greater body size and the psychophysical systems that detect them. The present work showed that greater body size in humans predicted increased knockout power during contests (Study 1a-1b: total N = 5,866; Study 2: N = 44 openweight fights). In agonistic exchanges reflective of ancestral size asymmetries, heavier combatants were 300% more likely to win against their lighter counterparts solely because they were 300% more likely to knock them out (Study 2). Greater body size afforded no other fighting performance advantages other than increased knockout power (Studies 1-2). Human dominance judgments (total N = 500 MTurkers) accurately tracked the frequency with which men (N = 516) had knocked out similar sized adversaries (Study 3). Humans were able to directly perceive a man’s knockout power solely because they were attending to cues of a man’s body size. Human dominance judgments—which are important across numerous psychological domains, including attractiveness, leadership, and legal decision-making—accurately predict the likelihood with which a potential mate, ally, or rival can incapacitate their adversaries.

Do the Big Five Personality Traits Interact to Predict Life Outcomes? Systematically Testing the Prevalence, Nature, and Effect Size of Trait by Trait Moderation

Vize, Colin, Brinkley M. Sharpe, Josh Miller, Donald Lynam, and Christopher J. Soto. 2022. “Do the Big Five Personality Traits Interact to Predict Life Outcomes? Systematically Testing the Prevalence, Nature, and Effect Size of Trait by Trait Moderation.” PsyArXiv. June 28. doi:10.31234/osf.io/b5ph8

Abstract: Personality researchers have posited multiple ways in which the relations between personality traits and life outcomes may be moderated by other traits, but there are well-known difficulties in reliable detection of such trait-by-trait interaction effects. Estimating the prevalence and magnitude base-rates of trait-by-trait interactions would help to assess whether a given study is suited to detect interaction effects. We used the Life Outcomes of Personality Replication Project dataset to estimate the prevalence, nature, and magnitude of trait-by-trait interactions across 81 self-reported life outcomes (n ≥ 1,350 per outcome). Outcome samples were divided into two halves to examine the replicability of observed interaction effects using both traditional and machine-learning indices. The study was adequately powered (1 − β ≥ .80) to detect the smallest interaction effects of interest (interactions accounting for a ΔR2 of approximately .01) for 78 of the 81 (96%) outcomes in each of the partitioned samples. Results showed that only 40 interactions (5.33% of the original 750 tests) showed evidence of strong replicability through robustness checks (i.e., demographic covariates, Tobit regression, ordinal regression). Interactions were also uniformly small in magnitude. Future directions for research on trait-by-trait interactions are discussed.

Divergent thinking and creative achievement—Marginally relevant link

Said-Metwaly, S., Taylor, C. L., Camarda, A., & Barbot, B. (2022). Divergent thinking and creative achievement—How strong is the link? An updated meta-analysis. Psychology of Aesthetics, Creativity, and the Arts. Advance online publication. https://doi.org/10.1037/aca0000507

Abstract: Achieving creativity in the real-world depends on multiple individual and environmental factors. Among them, divergent thinking (DT) has long been considered a key ingredient of creativity and an essential criterion for predicting real-life creative outcomes. However, the link between DT and creative achievement (CA) has yielded heterogeneous results, as outlined by a prior meta-analysis on the DT–CA link published in 2008. Given several limitations of this meta-analysis and the large body of relevant studies that have been published since then, the present article aimed to offer an updated and methodologically rigorous meta-analytical examination of the DT–CA link. A total of 766 effect sizes from 70 studies encompassing 14,901 subjects were analyzed using a meta-analytic three-level model. The results showed that DT was positively, albeit weakly, linked to CA, with only 3% of shared variance. Moderator analyses indicated that this link was robust to variations in DT and CA measures used, gender, educational level, measurement interval between DT and CA, and country of study, but differed by DT task modality, CA domain, and intellectual giftedness. Specifically, the strength of the DT–CA link was significantly larger for (a) verbal DT tasks, (b) CA in the performance domain, and (c) gifted subjects. A significant interaction effect was also found between CA domain and intellectual giftedness, with the DT–CA link being strongest among gifted subjects in the performance domain. Implications of these results for the study and measurement of creativity are discussed.

Just Seconds of Laughter Reveals Relationship Status: Laughter with Friends Sounds More Authentic , Relaxed and Less Vulnerable than Laughter with Romantic Partners

Just Seconds of Laughter Reveals Relationship Status: Laughter with Friends Sounds More Authentic and Less Vulnerable than Laughter with Romantic Partners. Sally D. Farley, Deborah Carson & Susan M. Hughes. Journal of Nonverbal Behavior, Jul 1 2022. https://rd.springer.com/article/10.1007/s10919-022-00406-5

Abstract: The dual pathway model posits that spontaneous and volitional laughter are voiced using distinct production systems, and perceivers rely upon these system-related cues to make accurate judgments about relationship status. Yet, to our knowledge, no empirical work has examined whether raters can differentiate laughter directed at friends and romantic partners and the cues driving this accuracy. In Study 1, raters (N = 50), who listened to 52 segments of laughter, identified conversational partner (friend versus romantic partner) with greater than chance accuracy (M = 0.57) and rated laughs directed at friends to be more pleasant-sounding than laughs directed at romantic partners. Study 2, which involved 58 raters, revealed that prototypical friendship laughter sounded more spontaneous (e.g., natural) and less “vulnerable” (e.g., submissive) than prototypical romantic laughter. Study 3 replicated the findings of the first two studies using a large cross-cultural sample (N = 252). Implications for the importance of laughter as a subtle relational signal of affiliation are discussed.

General Discussion

In these studies, we demonstrated that raters exceeded chance in determining relationship status (friend versus romantic) based on brief vocal samples of laughter, that friendship laughter sounds more authentic (louder, more relaxed, more natural, and more variable/”changing”) than romantic laughter, and that these judgments were consistent across five unique cultures. In addition, we found support for the vulnerable love hypothesis—romantic laughter sounded warmer, more feminine and more submissive than friendship laughter.

The ability of raters to identify the conversational partner (friend versus romantic) with greater than chance accuracy complements previous work on laughter’s ability to signal important information about the relationship between co-laughers (Bryant & Aktipis, 2014; Bryant et al., 2018; Lavan et al., 2016). But this research goes beyond previous work by revealing that raters can differentiate between laughter directed at two types of dyads that are both high in affiliation—friends and romantic partners. For a variety of reasons (motivational and emotional), we maintained that laughter directed at friends was more authentic than laughter directed at romantic partners, and the tendency for friendship laughter to be more accurately identified than romantic laughter implicates it as more authentic (Bryant & Aktipis, 2014). In addition, raters’ judgments of relationship status (friend versus romantic) were reliably linked to subjective characteristics of laughter authenticity. Laughter between friends was perceived as louder, more natural-sounding, more changing/variable (in Studies 2 and 3), breathier (in Study 2), and more relaxed (in Study 3).

Vulnerable Love Hypothesis

In Studies 2 and 3, we found support for the notion that laughter cues reveal the vulnerable relationship status of early-stage romantic love. Other work has shown that raters can differentiate friends and romantic partners via 20 s of content-masked clips and short content-controlled clips such as “How are you?” (Farley et al., 2013), but it is impressive that this skill extends to brief segments of laughter. The intimate voice associated with romantic love is softer, higher in pitch, and more submissive-sounding (Montepare & Vega, 1988), and these vulnerability-type cues were effective at differentiating romantic laughter from friendship laughter in our work. Specifically, in Studies 2 and 3, romantic laughter was perceived to be quieter, more feminine-sounding, and more submissive, and in Study 2, when the measure was used, more baby-like. From an evolutionary standpoint, vocal cues such as these serve to communicate “I mean you no harm” (Bryant, 2020; Gervais & Wilson, 2005). Moreover, romantic laughter was perceived as less pleasant-sounding than friend laughter, which dovetails with other research finding that masked clips of vocal cues from romantic partners are evaluated less favorably than clips from friends (Farley et al., 2013; Montepare & Vega, 1988). Early-stage romantic love is marked by a great deal of tumultuous physiological arousal and uncertainty, and romantic love renders individuals to be highly dependent on their relationships (Hatfield & Rapson, 1993a, 1993b). This might translate into a vocal style lacking in confidence and attractiveness.

The female advantage in nonverbal sensitivity (Knapp et al., 2014) was generally unsupported in this research. However, in Study 3, gender interacted with partner type. For arguably more “authentic” friendship samples, which may be easier to identify (Bryant & Aktipis, 2014), men and women performed similarly well. But for the potentially less “authentic” romantic samples, which were more challenging for raters, women’s accuracy was significantly higher than men’s. This is a unique finding given that sex differences in accuracy have not emerged in previous research (Bryant & Aktipis, 2014; Bryant et al., 2018). This female advantage to accurately decipher romantic intent via laughter may be explained by the Error Management Theory which predicts that women have an evolved bias to be skeptical of men’s commitment (Haselton & Buss, 2000), and therefore may be more in tune to discriminating signals of men’s romantic intent through a variety of means. Further, the cross-cultural ability of individuals to do this provides support for the evolutionary significance of laughter as a signal of relational import.

The research presented here augments an impressive body of work on the accuracy of thin slices of behavior (Ambady & Rosenthal, 1992). Not only can individuals make accurate inferences about important social dimensions such as sexual orientation (Rule, 2017), status (Bjornsdottir & Rule, 2017), and leadership emergence in organizations (Re & Rule, 2017) based on photographs, individuals discern critical relational information based on vocal cues (Farley et al., 2013; Hughes & Harrison, 2017; Montepare & Vega, 1998). Laughter is potentially unique because it not only reflects or signals affiliation (Brown et al., 2018), but it is also capable of enhancing relationship quality (Kurtz & Algoe, 2015, 2017). The role of laughter in signaling relational information internally within the dyad and externally to observers also supports social functional accounts of emotion, such as the emotions as social information model (EASI) (Van Kleef, 2009).

Limitations and Future Directions

The current investigations were not without some limitations. The first two studies had relatively smaller samples sizes and the second study did not include comprehensive demographics of the sample. Study 3 addressed these limitations by demonstrating ubiquity in our findings through the use of a large cross-cultural sample diverse on Hofstede’s (2011) six cultural values. Interestingly, the sample from the United States in Bryant et al. (2018) was least accurate at making forced-choice decisions from the sample of laughs from their own culture, which converges with our results from Study 3. Examination of this curious finding would be a fruitful area of future investigation.

Using the laugh samples that were the most identifiable in terms of discerning whether they were directed toward a friend or a romantic partner (Study 2) allowed us to better comprehend what specific subjective perceptions may have contributed to the success of discriminating between samples. However, whereas these samples served as good prototypes for investigation, it limits the generalizability of the findings. We attempted to account for this limitation in Study 3 by selecting different laughter samples that were not prototypical representations, and this method yielded similar findings. Study 3 also redressed a limitation from Study 2 in which we had to account for an experimental error where we had to omit some of the ratings for a set of participants as described above.

Although a unique constellation of acoustic features contributes to the perception of vocalizations (Babel et al., 2014), pitch appears to be one of the most salient features in vocal discrimination (for review see Puts et al., 2014) and is an indicator of arousal (Bryant & Aktipis, 2014; Ruch & Ekman, 2001). Examining how detailed acoustic parameters impacts perception was beyond the scope of this study as our focus was to explore subjective assessments made by listeners. However, future studies should consider the variety of acoustic features of laughter such as pitch, perhaps even through artificial manipulation, to see how they affect different percepts of laughter within romantic and non-romantic contexts. In addition, this research expanded the work of previous investigations, which have only examined female laughers (e.g., Bryant & Aktipis, 2014; Bryant et al., 2018; Lavan et al., 2016), but more studies are needed to understand sex differences in both the expression and perception of laughter across different contexts.

Our investigation examined the laughter between couples who were at the advent of their romantic relationships. It would be prudent to examine laughter obtained from couples during the early versus later stages of their relationships. Laughter appears to be an important factor throughout a couple’s exchange; it frequently occurs during courtship (with men being more likely to use women’s responsive laughter to gauge their interest; Hall, 2015), and mutual laughter has also been linked to long-term relationship satisfaction (Hall, 2013). Yet, romantic relationships often trade the early novelty and volatility of romantic love for security and commitment over time, potentially rendering the laughter of long-term romantic partners to sound similar to that of friends. This avenue could also benefit from examining how self-reported feelings for one’s romantic partner correlate with the sound of one’s laughter.

Among r/AntiVegan users there is a group of ex-vegans seeking health advice & social support; it was observed an enhanced group commitment over time, including an increase in group-focused language & a decrease in cognitive processing

‘Against the cult of veganism’: Unpacking the social psychology and ideology of anti-vegans. Rebecca Gregson, Jared Piazza, Ryan L.Boyd. Appetite, July 1 2022, 106143. https://doi.org/10.1016/j.appet.2022.106143

Abstract: Despite the established health and ecological benefits of a plant-based diet, the decision to eschew meat and other animal-derived food products remains controversial. So polarising is this topic that anti-vegan communities — groups of individuals who stand vehemently against veganism — have sprung up across the internet. Much scholarship on veganism characterizes anti-vegans in passing, painting them as ill-informed, uneducated, or simply obstinate. However, little empirical work has investigated these communities and the individuals within them. Accordingly, we conducted a study using social media data from the popular platform, Reddit. Specifically, we collected all available submissions (∼3523) and comments (∼45,528) from r/AntiVegan subreddit users (N = 3819) over a five-year period. Using a battery of computerized text analytic tools, we examined the psychosocial characteristics of Reddit users who publicly identify as anti-vegan, how r/AntiVegan users discuss their beliefs, and how the individual user changes as a function of community membership. Results from our analyses suggest several individual differences that align r/AntiVegan users with the community, including dark entertainment, ex-veganism and science denial. Several topics were extensively discussed by r/AntiVegan members, including nuanced discourse on the ethicality and health implications of vegan diets, and the naturalness of animal death, which ran counter to our expectations and lay stereotypes of r/AntiVegan users. Finally, several longitudinal changes in language use were observed within the community, reflecting enhanced group commitment over time, including an increase in group-focused language and a decrease in cognitive processing. Implications for vegan-nonvegan relations are discussed.

Keywords: Text analysisSocial mediaRedditGroup identificationVeganism

Males reported more positive outcomes from threesomes than did females, particularly when engaging with two members of the other sex

An Empirical Investigation of Variations in Outcomes Associated with Heterosexual Adults’ Most Recent Mixed-Gender Threesome Experience. Ashley E. Thompson, McKenna Osborn, Katie Gooch & Mariah Ravet. Archives of Sexual Behavior, Jun 29 2022. https://rd.springer.com/article/10.1007/s10508-022-02299-3

Abstract: Research reveals that a substantial proportion of North American adults report interest in and experience with mixed-sex threesomes (MSTs; sexual activity involving three people at the same time in which persons of more than one sex are present). Despite the prevalence of MST participation, little is known about the outcomes of MST experiences. Thus, the current study assessed MST outcomes using various metrics including the extent to which one’s most recent MST met expectations, the likelihood of participating in the MST again, and whether an orgasm was experienced. In addition, the extent to which one’s sex, the sex of those involved, and the inclusion of one’s romantic partner impacted outcomes was examined. Data from 276 heterosexual adults (217 men, 59 women) revealed that, overall, adults report fairly positive outcomes from their most recent MST and that males reported more positive outcomes than did females (particularly when engaging in a MST with two members of the other sex). In addition, MSTs involving one’s romantic partner resulted in more positive outcomes than did those with casual partners. These results confirm that MSTs can be a satisfying experience particularly for heterosexual males and those participating with a romantic partner. Implications for educators looking to destigmatize various forms of nonmonogamies and for practitioners who intend to assist adults interested in safely exploring multi-person sexual behavior are discussed.

Users with toxic usernames produce more toxic content (of various types) than those with neutral usernames

Namespotting: Username toxicity and actual toxic behavior on reddit. Rafal Urbaniak et al. Computers in Human Behavior, July 1 2022, 107371. https://doi.org/10.1016/j.chb.2022.107371

Highlights

• First large-scale comparative exploration of the toxic behavior of Reddit users with toxic usernames.

• Our analysis employs algorithmic methods and Bayesian statistical models without relying on self-reported data.

• Users with toxic usernames produce more toxic content (of various types) than those with neutral usernames.

• Users with toxic usernames are more likely to have their account suspended than those with neutral usernames.

Abstract

Without relying on any user reports, we use algorithmic detection and Bayesian statistical methods to analyse two large data streams (329 k users) of Reddit content to study the correlations between username toxicity (of various types, such as offensive or sexually explicit) and their online toxic behavior (personal attacks, sexual harassment among others).

As it turns out, username toxicity (type) is a useful predictor in online profiling. Users with toxic usernames produce more toxic content than their neutral counterparts, with the difference in predicted mean increasing with activity (predicted 1.9 vs. 1.4 toxic comments a week for users with regular activity, and 5.6 vs. 4 for top 5% active users). More users with toxic usernames engage in toxic behavior than among neutral usernames (around 40% vs. 30%). They are also around 2.2 times more likely to have their account suspended by moderators (3.2% vs. 1.5% probability of suspension for regular and 4.5% vs. 2% for top 5% users)—detailed results vary depending on the username toxicity type and toxic behavior type. Thus, username toxicity can be used in the efforts of online communities to predict toxic behavior and to provide more safety to their users.

Keywords: Verbal aggression onlineUsernamesSocial mediaArtificial intelligenceBayesian data analysisReddit

☆ During the study, we have utilized content that is publicly available on Reddit.com and can be accessed via the Reddit API or other similar technologies. Since usernames were essential for the analysis, we could not fully anonymize them in the released datasets, but to provide our subjects more anonymity (even though Reddit is characterized by site-wide norms which discourage from using one's real name Proferes, Jones, Gilbert, Fiesler, & Zimmer, 2021), we have additionally obfuscated usernames with an alteration that will greatly impede if not prevent from accessing the account of each individual, but without changing the semantics of the usernames. This study was also not interventional research and no posts or comments of particular users are quoted. To maximize confidentiality, as a part of the released datasets, we have included the summarised data points only with the already aforementioned altered usernames. For these reasons, we assume that no distress or harm might be involved and no informed consent was required (following point 8.05 of the Ethical Principles of Psychologists and Code of Conduct of the American Psychological Association). All the data sets, source code, and technical documentation are available at https://rfl-urbaniak.github.io/namespotting/. The toxicity identification tools are not open-sourced, but its use is free for researchers in academia and NGOs, and anyone who contacts the company with the willingness to reproduce the result, will obtain access.

☆☆ Disclaimer is anonymised due to Double Blind Peer Review policy. ORCID(s)

☆☆☆ Some computing power and part of this research has been funded by National Science Center research grant number 2016/22/E/HS1/00304. More computing power and further research has been funded by Samurai Labs.

Informal access to medical expertise and services (like being parents of a doctor) is not an important cause of differences in health care use and mortality

Artmann, Elisabeth, Hessel Oosterbeek and Bas van der Klaauw. 2022. "Do Doctors Improve the Health Care of Their Parents? Evidence from Admission Lotteries." American Economic Journal: Applied Economics, 14(3):164-84. DOI: 10.1257/app.20190629

Abstract: To assess the importance of unequal access to medical expertise and services, we estimate the causal effects of having a child who is a doctor on parents' mortality and health care use. We use data from parents of almost 22,000 participants in admission lotteries to medical school in the Netherlands. Our findings indicate that informal access to medical expertise and services is not an important cause of differences in health care use and mortality.

Sleep deprivation led to larger impairments in those with higher fluid intelligence, evident for arithmetic ability, episodic memory, and a trend for spatial working memory

Balter, Leonie J., Tina Sundelin, Benjamin C. Holding, Predrag Petrovic, and John Axelsson. 2022. “Intelligence Predicts Better Cognitive Performance After Normal Sleep but Larger Vulnerability to Sleep Deprivation.” PsyArXiv. June 28. doi:10.31234/osf.io/qenm4

Abstract: It has been proposed that intelligence allows some people to cope better with stress than others. However, whether those with higher intelligence are also more resilient to the cognitive effects of insufficient sleep remains unclear. Participants (N = 182) were randomized to either a normal night of sleep or a night of total sleep deprivation. The Raven's Standard Progressive Matrices Test set E was used to estimate fluid intelligence prior to the experimental night. A sleepiness measure and a cognitive test battery were completed at 22:30h (serving as the baseline session for both groups), and the following day at 08:00h, 12:30h, and 16:30h after sleep manipulation. As per preregistration, sleepiness and measures of arithmetic ability, episodic word memory, simple attention, and spatial working memory were analyzed. At baseline, higher fluid intelligence was associated with fewer errors and faster calculations on the arithmetic test, and fewer episodic memory errors, but was not associated with spatial working memory performance, simple attention, or sleepiness. Sleep deprivation led to larger impairments in those with higher fluid intelligence, evident for arithmetic ability, episodic memory, and a trend for spatial working memory. Fluid intelligence did not predict vulnerability on any of the other tests or sleepiness. These data indicate that fluid intelligence is related to superior higher-order cognitive functioning under optimal sleep condition, but it does not protect against the deleterious cognitive effects of insufficient sleep. Further studies may test whether the cognitive benefits of intelligence are primarily limited to optimal situations.

To receive credit and to create favorable impressions, individuals need to share information about their past accomplishments; claiming credit to demonstrate competence, however, can harm perceptions of warmth and likability

VanEpps, Eric and Hart, Einav and Hart, Einav and Schweitzer, Maurice E., Dual-promotion: Bragging Better by Promoting Peers (June 3, 2022). SSRN: http://dx.doi.org/10.2139/ssrn.4128132

Abstract: To receive credit and to create favorable impressions, individuals need to share information about their past accomplishments. Claiming credit to demonstrate competence, however, can harm perceptions of warmth and likability. In fact, prior work has conceptualized self-promotion as a hydraulic challenge: tactics that boost perceptions along one dimension (e.g., competence) harm perceptions along the other dimensions (e.g., warmth). In this work, we identify a novel approach to self-promotion: We show that by combining other-promotion (promoting others) and self-promotion, which we term “dual-promotion”, individuals can project both warmth and competence to make better impressions on observers. In two pre-registered pilot studies, including annual reports from members of Congress and an interactive lab study, we demonstrate that even when motivated to create a favorable impression, people rely heavily upon self-promotion. Yet across four experiments using workplace and political contexts (N = 1,510, pre-registered), we show that individuals who engage in dual-promotion consistently create more favorable impressions than those who only engage in self-promotion, an effect mediated by enhanced perceptions of both warmth and competence. These benefits also extend to behavioral intentions. In addition, we show that regardless of what colleagues and peers do, dual-promotion creates more favorable impressions than self-promotion, suggesting that sharing credit can be an optimal strategy across a variety of contexts.

Keywords: Self-promotion, Bragging, Credit sharing, Communication strategies, Open science
JEL Classification: D01, D03, D74, D81, D84

Reading language of the eyes

Reading language of the eyes. Marina A. Pavlova, Arseny A. Sokolov. Neuroscience & Biobehavioral Reviews, June 25 2022, 104755. https://doi.org/10.1016/j.neubiorev.2022.104755

Highlights

• In neurotypical individuals, RMET scores are tightly correlated with other social cognition skills;

• The RMET assesses recognition of facial affect, but also relies on receptive language comprehension and memory;

• RMET performance is underwritten by the large-scale ensembles of neural networks well-outside the social brain;

• The RMET is limited in its capacity to differentiate between neuropsychiatric conditions as well as between stages and severity of a single disorder;

• Merely gender rather than neurobiological sex impacts performance on the RMET.

Abstract: The need for assessment of social skills in clinical and neurotypical populations has led to the widespread, and still increasing use of the ‘Reading the Mind in the Eyes Test’ (RMET) developed more than two decades ago by Simon Baron-Cohen and colleagues for evaluation of social cognition in autism. By analyzing most recent clinical and brain imaging data, we illuminate a set of factors decisive for using the RMET. Converging evidence indicates: (i) In neurotypical individuals, RMET scores are tightly correlated with other social skills (empathy, emotional intelligence, and body language reading); (ii) The RMET assesses recognition of facial affect, but also heavily relies on receptive language skills, semantic knowledge, and memory; (iii) RMET performance is underwritten by the large-scale ensembles of neural networks well-outside the social brain; (iv) The RMET is limited in its capacity to differentiate between neuropsychiatric conditions as well as between stages and severity of a single disorder, though it reliably distinguishes individuals with altered social cognition or elevated pathological traits from neurotypical persons; (v) Merely gender (as a social construct) rather than neurobiological sex influences performance on the RMET; (vi) RMET scores do not substantially decline in healthy aging, and they are higher with higher education level, cognitive abilities, literacy, and mental well-being; (vii) Accuracy on the RMET, and engagement of the social brain, are greater when emotions are expressed and recognized by individuals with similar cultural/ethnic background. Further research is required to better inform usage of the RMET as a tool for swift and reliable examination of social cognition. In light of comparable visual input from the RMET images and faces covered by masks due to COVID-19 regulations, the analysis is of value for keeping efficient social interaction during the current pandemic, in particular, in professional settings related to social communication.

Keywords: Reading the Mind in the Eyes Test (RMET)visual social cognitionfacial affectsocial brainbrain imagingneuropsychiatrygender and sexclinical studieshealthy aging

Sexual humor was used to distinguish between primary and secondary sexual rewards; the amygdala serves as a reward hub, especially in processing sexual humor appreciation

Differential Neural Substrates for Responding to Monetary, Sexual Humor, and Erotic Rewards. lYu-Chen Chan, Wei-Chin Hsu, Tai-LiChou. Biological Psychology, June 28 2022, 108385. https://doi.org/10.1016/j.biopsycho.2022.108385

Highlights

• Sexual humor was used to distinguish between primary and secondary sexual rewards.

• The amygdala serves as a reward hub, especially in processing sexual humor appreciation.

• Sexual versus monetary rewards have been identified in the OFC along a postero-anterior axis.

• The pOFC-amygdala coupling was found for sexual humor appreciation and erotic pleasure.

• The NAc-midbrain coupling was active for anticipation of monetary rewards.

Abstract: Sexual humor involves neural mechanisms related to both humor and sexual arousal. However, evidence on the role of the amygdala in processing sexual humor is lacking. Unlike erotic stimuli that directly involve a biological drive, sexual humor gains its value through learned associations. Processes related to responding to erotic versus monetary rewards have been identified in the lateral orbitofrontal cortex (lOFC) along a postero-anterior axis, but it is less clear whether these processes are also active during the appreciation of sexual humor. Results showed the processing of sexual humor appreciation in the amygdala. Psychophysiological interaction (PPI) analysis further identified functional connectivity in the amygdala-midbrain coupling during sexual humor versus monetary gains appreciation. The present study provides evidence demonstrating roles for the posterior OFC (pOFC) and anterior OFC (aOFC) in distinguishing between sexual (sexual humor and erotic) and non-sexual (monetary) rewards. The experience of sexual pleasure induced by erotic rewards involves phylogenetically and ontogenetically older regions in the pOFC, while the experience of receiving monetary gains involves the aOFC. This study also provides additional insights into sexual humor appreciation in the pOFC, with findings of a postero-anterior dissociation in the processing of sexual humor appreciation. PPI analysis revealed functional connectivity in the pOFC-amygdala coupling in response to both types of sexual rewards versus monetary rewards. Together, our results suggest that the amygdala serves as a reward hub, especially in processing sexual humor versus monetary gains appreciation. Functional connectivity analysis showed amygdala-midbrain and pOFC-amygdala coupling during the appreciation of sexual humor.

Keywords: fMRIsexual rewardsamygdalaorbitofrontal cortexnucleus accumbens

4. Discussion

Sexual humor involves neural mechanisms related to both humor processing and sexual arousal. The amygdala has been found to play a key role in humor. However, evidence on the role of the amygdala in processing sexual humor is unclear. Many studies have focused on humor appreciation using cartoon stimuli (Bartolo et al., 2006, Goel and Dolan, 2001, Goel and Dolan, 2007, Mobbs et al., 2003, Samson et al., 2008, Samson et al., 2009, Wild et al., 2006). Humor does more than just make people laugh; it can serve numerous social functions as a ‘social glue’ (Bartolo et al., 2021, Chan et al., 2016, Goel and Dolan, 2007). However, few studies have made use of humor as a social reward (Chan et al., 2018a).

In this study, sexual humor was used as a reward to make it possible to distinguish between sexual humor and non-humor rewards (erotic and monetary). A large body of research has shown that the amygdala plays a core role in humor appreciation (Chan et al., 2012, Chan et al., 2013, Mobbs et al., 2003, Vrticka et al., 2013). However, empirical evidence on the role of the amygdala in processing sexual humor is lacking. As predicted, our results show that sexual humor rewards involve the bilateral amygdala during the experience of amusement (Fig. 3). The amygdala showed differentially greater activation to sexual humor rewards. This is consistent with a view in which the amygdala plays a crucial role in the ‘hedonic brain’ during the appreciation of humor rewards (Chan et al., 2018a). Based on the salience theory of humor (Ruch & Hehl, 1988), the amygdala, part of the ventral salience network (SN), may be involved in focusing attention on salient sexual and humor stimuli and then integrating cognitive and affective information related to the stimuli (Beaty et al., 2015, Beaty et al., 2019, Beaty et al., 2021, Menon and Uddin, 2010).

The first aim of this study was to investigate reward-related brain activity during the consumption of sexual humor and non-humor (erotic and monetary) rewards. The segregated response to sexual humor versus erotic outcomes (HO > EO) in the left amygdala suggests a functional division in the experience of humor-related amusement, perhaps related to hedonic value representation during humor appreciation. Sexual humor involves sexual arousal and humor appreciation (Chapman and Gadfield, 1976, Ruch and Hehl, 1988), while erotic stimuli involve primarily sexual arousal (Sescousse et al., 2010). Therefore, compared to the consumption of erotic rewards, the amygdala plays a core role in “humor appreciation” during the consumption of sexual humor rewards. This is consistent with previous findings that the amygdala contributes to humor appreciation (Chan, in press, Chan et al., 2012, Chan et al., 2013, Farkas et al., 2021, Mobbs et al., 2003, Vrticka et al., 2013). Additionally, the segregated responses to sexual humor appreciation versus monetary gains (HO > MO) in the bilateral amygdala suggest a role for reward-specific regions in the experience of amusement related to sexual humor. Together, our results support a key role for the amygdala in the hedonic enjoyment of sexual humor.

Psychophysiological interaction (PPI) analysis further revealed amygdala-midbrain coupling and amygdala-ACC coupling in response to sexual humor appreciation when compared with the response to the non-reward baseline (HO > NO). The amygdala seed of the salience network showed positive correlations with another salience network (the ACC and midbrain). The results are consistent with the Freudian theory of humor and sexual arousal. Sexual humor appears to be funnier (Chan et al., 2016). The contrast between erotic rewards and sexual humor rewards (EO > HO) suggests increased biological drive supported by the functional coupling of the NAc-ACC (Fig. 5). Additionally, the contrast between sexual humor rewards and monetary rewards (HO > MO) revealed increased sexual arousal and amusement in the amygdala-midbrain coupling. The results of the present study are consistent with previous findings on amygdala-midbrain coupling for the consumption of humor versus monetary rewards (HO > MO) (Chan et al., 2018a). In sum, the appreciation of sexual humor rewards elicited sexual arousal and amusement via amygdala-midbrain connectivity.

The second aim of this study was to investigate reward-related brain activity during the consumption of sexual (sexual humor and erotic) and non-sexual (monetary) rewards. In this study, sexual humor and erotic stimuli were used as sexual rewards to make it possible to distinguish between sexual and non-sexual rewards. The lOFC is known to play a key role in encoding reward-related value, memory, and semantic processing (Sescousse et al., 2010, Zald et al., 2014). Previous studies have shown that reward value processing during the consumption of erotic versus monetary rewards in the lateral OFC (lOFC) occurs along a postero-anterior axis (Li et al., 2015, Sescousse et al., 2013). In the outcome phase, the processing of erotic pleasure has been found in phylogenetically and ontogenetically older parts of the posterior lOFC (pOFC, MNI (x y z), -30, 33, -15), while the processing of monetary gains has been found in phylogenetically more recent parts of the anterior lOFC (aOFC, -30, 51, 0) (Sescousse et al., 2010). The present study further used sexual humor rewards and found that the processing of reward value coding in the outcome phase for sexual humor appreciation versus monetary gains can be identified in the posterior lOFC (pOFC).

Visual sexual stimuli as rewards may trigger autonomic sexual arousal for humans (Putkinen et al., 2022). As predicted, processing related to hedonic experiences by reward-specific brain networks along a postero-anterior axis appears to be what is reflected in value-related lOFC activity during the outcome phase (Fig. 4). The pleasure of sexual arousal (in response to both sexual humor and erotic stimuli) revealed increased activation in the posterior part of the lOFC (pOFC), while processing for monetary gains showed increased activation in the anterior part of the lOFC (aOFC). In term of sexual rewards, sexual humor appreciation versus monetary gains (HO > MO) specifically recruited activation in the bilateral pOFC (MNI = -42, 28, -8 and MNI = 34, 30, -16), while erotic pleasure versus monetary gains (EO > MO) elicited activation in the left pOFC (-28, 30, -12). In term of non-sexual rewards, monetary versus sexual humor rewards (MO > HO) elicited greater activation in the aOFC (34, 54, -4); monetary versus erotic rewards (MO > EO) similarly elicited more aOFC activation (34, 54, -2). The postero-anterior distinction of the lOFC was shown. The more complex or abstract rewards (e.g., monetary gain or loss) showed increased activation in the aOFC, while less complex rewards (e.g., erotic or taste stimuli) showed increased activation in the pOFC (Kringelbach, 2005, Kringelbach and Rolls, 2004).

Previous studies have used happy faces (Spreckelmeyer et al., 2009), social feedback (e.g., praise or compliments) (Fussner et al., 2018), social decision making (Izuma et al., 2008), and affective touch (Korb et al., 2020) as social rewards. Humor is another type of reward that plays an important role in social relations (Chan et al., 2018a). The present study used sexual humor as a social reward. The results of the present study identified a role in sexual humor appreciation for the pOFC during the outcome phase. In contrast, previous studies have shown processing of social rewards in a similar aOFC region (Izuma et al., 2008). A possible interpretation for the results of the present study is that sexual humor rewards involve both sexual arousal and humor appreciation. This may be consistent with previous findings that the pOFC contributes to the experience of sexual arousal related to erotic rewards (Sescousse et al., 2010). Sescousse et al.’s study showed increased activation for monetary gains versus erotic pleasure in the left aOFC (-30, 51, 0) during the outcome phase (Sescousse et al., 2010). However, the present study showed activation for both monetary gains versus erotic rewards (MO > EO) and monetary gains versus sexual humor rewards (MO > HO) in the bilateral aOFC, especially increased activation in the right aOFC (MNI = 34, 54, -4 and MNI = 34, 54, -2). Future studies might further examine the neural mechanisms related to processing monetary gains in the left or right aOFC with different types of rewards.

Another interesting question relates to how to interpret differences in functional connectivity between sexual reward conditions. Our PPI analysis demonstrated the functional connectivity of the pOFC (-42, 28, -8) as a seed, showing pOFC-amygdala, pOFC-NAc, and pOFC-ACC couplings in response to sexual humor appreciation versus monetary gains (HO > MO) during the outcome phase, while the functional connectivity of the pOFC (-28, 30, -12) as a seed showed pOFC-amygdala and pOFC-ACC couplings in response to erotic pleasure versus monetary gains (EO > MO) during the outcome phase (Fig. 6). Taken together, it appears that sexual rewards elicit sexual pleasure via pOFC-amygdala and pOFC-ACC connectivity.

Our findings implicate the pOFC in sexual pleasure related to both sexual humor and erotic stimuli. Also, the hypothalamus, which plays a core role in human sexual motivation and pleasure, is known to be particularly sensitive to the presentation of visual erotic stimuli (Sescousse et al., 2013). In our study, the erotic versus monetary rewards conditions (EO > MO) revealed greater activation in the hypothalamus (-8, -6, -4) during the outcome or consumption phase. This is consistent with previous studies on sexual arousal and sexual pleasure (Karama et al., 2002, Sescousse et al., 2013).

Finally, the third aim of this study was to investigate reward-related brain activity during monetary and non-monetary (sexual humor and erotic stimuli) motivation. The present study investigated neural mechanisms for cue-triggered motivation during the anticipation phase. We used a range of monetary rewards (10 to 12 New Taiwan Dollars) for successfully completed trials and showed cumulative earnings at the end of each monetary reward trial, in order to provide immediate feedback (as in the tasks with other reward types). During the anticipation phase, as predicted, we found the most prominent modulation in response to monetary cues, indicating the NAc’s role as a ‘monetary incentive center’ (Fig. 2; Chan et al., 2018a; Knutson et al., 2001a). The present study provided additional support related to the role of the NAc in motivating responses to monetary incentives in the anticipation of monetary rewards versus sexual humor rewards (MA > HA) and monetary rewards versus erotic rewards (MA > EA).