Thursday, May 26, 2022

More nails in the monogamy coffin: Offspring in stable, monogamous gibbon families have an extra-group father in 40pct of cases; the breeding system of crested gibbons is more flexible than previously thought (understatement of the week)

Disassociation of social and sexual partner relationships in a gibbon population with stable one-male two-female groups. Xia Huang et al. American Journal of Primatology, May 25 2022.

Abstract: Adult males living in a one-male multi-female social group are expected to try to monopolize copulations with resident females to increase reproductive fitness. Gibbons have traditionally been described as living in monogamous groups, with the sole resident adult male assumed to sire all of the group's offspring. Here, we used microsatellite analyses and behavioral observations to examine rates of extra-group paternity (EGP) over 16 years in a population of crested gibbons (Nomascus concolor) that form stable and long-term one-male two-female social units. Forty percent of offspring (N = 14) were sired by extra-group males. To understand this high level of EGP, we tested whether inbreeding avoidance was related to EGP. Females who engaged in EGP did not show larger pairwise relatedness with their resident male compared to females who did not engage in EGP. Nevertheless, the standardized heterozygosity of EGP offspring was significantly higher than for offspring sired by the group's resident male. These results provide partial support for the inbreeding avoidance hypothesis. It appears that resident male crested gibbons are unable to monopolize resident females' matings. Our results indicate that long-term social partners are often distinct from sexual partners in this population. Clearly, the breeding system of crested gibbons is more flexible than previously thought, indicating a need for integrating long-term behavioral data and genetic research to re-evaluate gibbon social and sexual relationships derived from concepts of monogamy and pair-bonding.


First study of reproductive strategies in a gibbon population with stable one-male two-female groups.

Confirmed unexpectedly high rate of extra-group paternity.

Females engaged in extra-group paternity to increase offspring heterozygosity.

High flexibility in gibbon breeding systems.

Female–male mounting in Japanese macaques: Some males may utilize FMM in a quest for their own sexual stimulation, which sometimes culminated in masturbation by the male

When males have females on their backs: Male's tolerance, solicitation, and use of female–male mounting in Japanese macaques. NoĆ«lle Gunst, Jean-Baptiste Leca, Paul L. Vasey. American Journal of Primatology, May 25 2022.

Abstract: Previous research on Japanese macaques has shown that female-to-male mounting (FMM) is performed by some females as an exaggerated form of sexual solicitation that may occur in the context of high female competition for male mates. This supernormal courtship behavior functions to prompt subsequent male-to-female mounting. In this report, we focused on the male consort partners' responses to FMM. We studied a free-ranging population of Japanese macaques at Arashiyama, Japan, in which FMM is frequent and prevalent. We analyzed 240 consortships involving 31 females and 19 males. We tested three hypotheses regarding male's tolerance, solicitation, and use of FMM. First, we found that FMM was tolerated by male mountees who were no more likely to aggress their female partners during a short time window around a FMM than they were during the rest of the consortship period. Second, we showed that FMM could be triggered by male recipients, via explicit male-to-female sexual solicitations. Third, we found that some males may utilize FMM in a quest for their own sexual stimulation, which sometimes culminated in masturbation by the male during FMM. Our findings indicate that male partners facilitate the expression of FMM both passively (via their tolerance) and actively (via their solicitation). In addition, FMM appears to enhance the sexual arousal of male partners during consortships. We argued that, for females to have expanded their repertoire of sexual solicitations by adopting FMM, male mates must have played a role in the evolutionary origins and maintenance of this nonconceptive but intense and powerful female mating tactic.

Research Highlights

Previous research in Japanese macaques has shown that female-to-male mounting (FMM) is a supernormal courtship behavior that functions to prompt subsequent male-to-female mounting.

As mounting is a male-typical behavior, we studied male consort partners' responses towards FMM in a free-ranging population of Japanese macaques in which this behavior is particularly frequent and prevalent.

By tolerating and triggering the performance of FMM in their female mates, males may have passively and actively contributed to the evolution and maintenance of this sexual adaptation, while deriving sexual gratification from this behavior.

Compared with gay and heterosexual men, asexual men demonstrated lower genital and subjective sexual arousal to the erotic films but displayed similar sexual arousal when engaging in sexual fantasy

Patterns of Genital and Subjective Sexual Arousal in Cisgender Asexual Men. Malvina N. Skorska et al. The Journal of Sex Research, May 24 2022.

Abstract: Human asexuality has been defined as a lack of sexual attraction to others, although its nature is not well understood. Asexual men’s genital and subjective sexual arousal patterns were compared to sexual men’s to better understand asexual men’s sexual response patterns. Using a penile plethysmograph to measure genital arousal, 20 asexual, 27 heterosexual, and 22 gay cisgender men (M age = 28.28, SD = 9.41) viewed erotic films depicting sexual activity or masturbation, and a subsample engaged in sexual fantasy of their choosing. Questionnaires assessing sexual function and behavior were also completed. Asexual men scored lower on sexual desire and orgasmic function, higher on sexual aversion, and did not differ on overall sexual satisfaction. Compared with gay and heterosexual men, asexual men demonstrated lower genital and subjective sexual arousal to the erotic films but displayed similar sexual arousal when engaging in sexual fantasy. Asexual men’s lower levels of sexual excitation rather than their higher levels of sexual inhibition were associated with lower responses to the erotic films. These findings suggest asexual men have preferred sexual stimuli that differ from sexual men and have a similar capacity for sexual arousal as sexual men. Collectively these findings add to a growing literature aiming to understand the nature of asexuality.

Why Is Greater Income Inequality Associated with Lower Life Satisfaction and Poorer Health? Evidence from the European Quality of Life Survey, 2012

Nettle, Daniel, and Thomas E. Dickins. 2022. “Why Is Greater Income Inequality Associated with Lower Life Satisfaction and Poorer Health? Evidence from the European Quality of Life Survey, 2012.” PsyArXiv. May 19. doi:10.31234/


Background. Across countries and states, greater income inequality is associated with lower wellbeing. There are multiple causal pathways that could produce such an association. If the relationship of individual income to wellbeing is downward concave, greater dispersion of the income distribution must reduce average wellbeing. More unequal countries may also provide their residents with worse public services and amenities. Finally, increasing inequality may have direct psychosocial effects by heightening competitiveness and social anxiety.

Objectives. Using data from the European Quality of Life Survey 2012, we evaluated the contributions of different causal pathways to associations between income inequality and (a) life satisfaction and (b) self-rated health.

Methods. Secondary analysis of 27,571 respondents from 28 countries.

Results. In unadjusted analyses, greater income inequality was associated with lower life satisfaction and poorer self-rated health. Of the association between inequality and life satisfaction, 43% was attributable to individual income effects, and 41% to worse public services (especially access to healthcare), leaving 16% possibly due to direct psychosocial effects. The association between income inequality and self-rated health was mainly (68%) due to individual income effects, with the remainder possibly attributable to psychosocial effects. For life satisfaction, we found some evidence of costs of inequality that fall on those with high incomes, though this was not the case for self-rated health.

Conclusion. The negative associations between income inequality and wellbeing across European countries are in substantial part due to individual income effects. For life satisfaction, a further portion is attributable to worse public services. For life satisfaction but not self-rated health, income inequality has some negative consequences for those on high incomes as well as low incomes.

Whole-brain dynamics differentiate among cisgender and transgender individuals

Whole-brain dynamics differentiate among cisgender and transgender individuals. Carme Uribe et al. Human Brain Mapping, Apr 28 2022.

Abstract: How the brain represents gender identity is largely unknown, but some neural differences have recently been discovered. We used an intrinsic ignition framework to investigate whether there are gender differences in the propagation of neural activity across the whole-brain and within resting-state networks. Studying 29 trans men and 17 trans women with gender incongruence, 22 cis women, and 19 cis men, we computed the capability of a given brain area in space to propagate activity to other areas (mean-ignition), and the variability across time for each brain area (node-metastability). We found that both measurements differentiated all groups across the whole brain. At the network level, we found that compared to the other groups, cis men showed higher mean-ignition of the dorsal attention network and node-metastability of the dorsal and ventral attention, executive control, and temporal parietal networks. We also found higher mean-ignition values in cis men than in cis women within the executive control network, but higher mean-ignition in cis women than cis men and trans men for the default mode. Node-metastability was higher in cis men than cis women in the somatomotor network, while both mean-ignition and node-metastability were higher for cis men than trans men in the limbic network. Finally, we computed correlations between these measurements and a body image satisfaction score. Trans men's dissatisfaction as well as cis men's and cis women's satisfaction toward their own body image were distinctively associated with specific networks in each group. Overall, the study of the whole-brain network dynamical complexity discriminates gender identity groups, functional dynamic approaches could help disentangle the complex nature of the gender dimension in the brain.


For the first time, we characterize the spatiotemporal whole-brain dynamics of cisgender and transgender binary groups. Our findings corroborate the existence of four brain phenotypes (Guillamon et al., 2016; Uribe et al., 2020b) beyond the classic, lately questioned, conception that the human brain can be split into two configurations, the male and the female (Legato, 2018). To characterize the propagation of information and measure the degree of integration of spontaneously occurring events while at rest, we applied the intrinsic ignition framework (Deco & Kringelbach, 2017; Deco, Tagliazucchi, et al., 2017). This framework was very sensitive in detecting functional dynamics differences between young adults grouped by gender. Some of these group differences had been elusive when using stationary functional connectivity measurements (Uribe et al., 2020b), or sliding windows approach to study brain connectivity states (Uribe et al., 2021). In addition, spatial and temporal brain dynamics measurements were specifically related with the satisfaction toward body parts for cis men, cis women, and trans men.

The main novelty here is that we provide the first description of the spatiotemporal dynamics underlying the gender dimension in the brain, and more importantly, characterize the regional contribution to the whole-brain dynamics. Mean-ignition is an informative measurement of the spatial diversity and broadness of communication across the brain. On the other hand, node-metastability captures the variability over time across the whole brain. Both the spatial and temporal variability that defined each gender group were widespread across the whole brain, with nodes from all functional networks. Likewise, when using a support vector machine algorithm inputting stationary group independent component maps and clinical data as features, four gender groups were obtained based on the different patterns of brain connectivity (Clemens et al., 2020). In addition, our results stress the importance of using fine-grained dynamic measurements to study spatiotemporal oscillations over grand averaged functional connectivity measurements; these latter enabling a more narrowed investigation of differences that would be accountable for gender, and the incongruence felt in the transgender community.

Group differences in the two subdivisions of the attentional networks and in executive control were in line with previous findings of functional connectivity differences, both stationary (Uribe et al., 2020a) and dynamic (Uribe et al., 2021). The particular group differences in the dorsal and the ventral subdivisions of the attentional network underline the need to study them separately. More relevantly, the spatial broadness of communication of nodes in the default mode network was higher in cis women with respect to cis men and trans men. Higher functional connectivity in default mode regions has been reported in cis women in contrast to cis men (Biswal et al., 2010; de Lacy et al., 2019; Ritchie et al., 2018). Also, in the transgender literature, weaker connectivity strength has been reported in these network regions in the trans men group in contrast to cis men (Feusner et al., 2017; Uribe et al., 2020a) and cis women (Feusner et al., 2017), but this finding is not generalized as other studies had negative reports (Clemens et al., 2017; Nota et al., 2017).

On the other hand, the reported pattern of activation in cis men relies on sensory–motor regions (Ritchie et al., 2018). The somatomotor network in the Schaefer parcellation included areas of motor action and sensory inputs from the external world, making it the network with the most direct interaction with our environment. Despite the previous relevance given to this functional network in understanding the own body perception and subsequently explaining the incongruence in transgender people (Burke et al., 2019; Manzouri et al., 2017), the intrinsic ignition framework only differentiated between cisgender groups in terms of temporal variability. Indeed, our previous work on functional connectivity dynamics identified a sensorimotor state, although no differences between trans- and cisgender groups were noted (Uribe et al., 2021). The spatial and temporal dynamism of the limbic network was greater in the cis man group than in trans men. On the other hand, increased limbic connectivity in transgender individuals has been reported when viewing “ambiguous, androgynous images of themselves morphed toward their gender identity” (Majid et al., 2020). Such findings should be further explored. Different functional MRI measurements do not permit further discussion, and greater integration, broadness of communication, and temporal variability do not necessarily translate to increased averaged connectivity.

The superior parietal cortex has been previously linked to gender differences when comparing cis men with cis women and transgender groups, structurally (Zubiaurre-Elorza et al., 2013) and functionally (Uribe et al., 2020b). The choice of the Schaefer parcellation (Schaefer et al., 2018) allowed a high representation of the temporal parietal network in terms of brain dynamics in agreement with temporoparietal junction findings in trans men with respect to cisgender groups (Manzouri et al., 2017). The spatial diversity and broadness of communication of temporal parietal regions were greater in cis men than in the other three gender groups, namely cis women, trans men, and trans women.

The fact that cis men present higher brain dynamism than other gender groups, especially cis women and trans men, would be in line with previous brain states occupancy where cis men occupied more combinations of connectivity patterns over time than cis women (Yaesoubi et al., 2015). Nonetheless, these results have not been consistently replicated, as has occurred with other brain flexibility measurements through brain states using sliding windows that reported differential regional brain dynamism for both cis men and cis women (Mao et al., 2017). In addition, the increased spatial and temporal variability of brain oscillations in cis men was not homogeneous across all networks, for instance, in the default mode network.

Trans women presented a lateralized predominance in the regions with the highest node-metastability in the left hemisphere. The discussion of these findings is hampered by the scarcity of the literature investigating gender differences in brain dynamism. To the best of our knowledge, previous reports of the gender effects in the lateralization of brain connectivity patterns found these were mostly comparable between a large sample of cis men and women, with two marginal findings that did not survive false discovery rate correction and were considered a trend-level effect (Agcaoglu et al., 2015; Eliot et al., 2021), although there was a marginal leftwards lateralization in cis women only in the inferior frontal cortex (Tomasi & Volkow, 2012). Given these and the small sample of individuals investigated, especially in the trans woman group, our results should be taken carefully.

Finally, the (dis)satisfaction toward one's own body parts is not simply associated with a specific network, but differently according to the group, which suggests a different way of understanding and accepting the body depending on gender. The trans men group image (dissatisfaction) relied on the ventral attentional, that is, salience network. If one key element in the construction of gender is the perception of our own body (Burke et al., 2019; Peelen & Downing, 2007), the salience network has been highly related to trans- and cisgender differences that may explain the gender incongruence (Uribe et al., 2020b; Uribe et al., 2021). However, such a landmark is not helpful for the functional correlates of cisgender groups. These differences in the network correlates could be driven by the fact that the trans men group scores were within the range of the unconformity toward the body parts—4–5 points in the Likert scale of Lindgren and Pauly (1975)—, while cisgender groups would range mainly within the neutral satisfaction scores (1– points). Another potential explanation is that trans- and cisgender individuals' ratings may not be comparable between groups as the reported dissatisfaction may underlie different reasons for transgender people in contrast to what it would mean for cisgender groups. The cis man group's satisfaction and/or neutrality was positively associated with the limbic network and negatively with executive control. On the other hand, the network with higher spatial dynamical complexity, that is, the default mode, was also associated with body parts satisfaction in cis women. These networks have been largely associated with gender groups' differences described in previous works (Clemens et al., 2017; Manzouri et al., 2017; Uribe et al., 2020b; Uribe et al., 2021). However, our work provide evidence that gender group differences depict interplay by a whole-brain network in terms of spatial and temporal variability that exceeds the rather specific correlates of the degree of satisfaction toward the own body.

Some shortcomings should be addressed in future works. First, the need to increase the sample size that would add more power to the findings. Currently ongoing collaborative initiatives like the ENIGMA initiative on transgender health are trying to overcome this persistent limitation in the neuroimaging field (Mueller et al., 2021). However, this initiative lacks standard acquisition protocols to reduce the variability among sites that may hamper group discrimination. Second, the menstrual cycle of cis women and trans men was not accounted as a variable of interest, while there is growing evidence of functional dynamic differences between the phases of the menstrual cycle (De Filippi et al., 2021). Likewise, the sexual orientation of all participants was not systematically assessed as a variable of interest (Frigerio et al., 2021; Guillamon et al., 2016; Skorska et al., 2021). Including minority gender groups when investigating the gender phenomenon in the brain is imperative to understand the complexity of the gender experience. Nonetheless, future studies should include other gender groups, such as nonbinary or other genderqueer identities. Our exploratory work could potentially impact awareness, the development of healthcare guidelines, societal and political evidence-based changes accounting for this heterogeneity, and improve the quality of life while raising visibility that can help fight stigma (Janssen & Voss, 2021). Finally, it is important to note that the sample characteristics and analytical approach employed here prevent us from discriminating actual gender identity differences from other phenomena such as experiences of stigma that transgender people may have undergone. Future experimental designs should address such issues.

The superior sound quality of vinyl records is largely a matter of expectations

Vinyl as Fine Wine: The Role of Expectation on the Perception of Music Format. Rickard Enstroem and Rodney Schmaltz. Front. Psychol., May 26 2022 |

Abstract: While vinyl, compact discs, and even eight-track tapes were traditionally promoted to consumers as producing superior sound, the introduction of compressed digital music, such as mp3s, was markedly different. Initially, one of the primary selling features of digital music was convenience and portability rather than sound quality. Recently, vinyl music sales have experienced a substantial resurgence. Waveforms from vinyl represent recorded music more accurately than compressed digital formats and have the potential to produce better sound. Even so, most music listeners do not reliably listen to music on audiophile quality high-end equipment. For this reason, we believe one aspect of vinyl sales is the expectation that vinyl quality is superior. In this study, we sought to isolate the contribution of expectation to perceived sound quality. Participants were asked to listen to a selection of music on either vinyl or mp3. Some participants were told that they were listening to vinyl when the musical selection was an mp3, while others were told they were listening to an mp3 while actually listening to vinyl. A multivariate analysis through a Canonical Correlation Analysis established that expectation of music format quality drove post-listening evaluations.


A multivariate analysis through a canonical correlation model demonstrated that expectation plays a pervasive and salient role in judging vinyl and mp3 recorded music formats. That is, the experience of listening to music is impacted by expectation and not due to sound quality alone. Our results can be interpreted through a Bayesian lens regarding the interplay between prior expectations and sensory evidence. Our results suggest that for vinyl, the expectations in terms of sound quality are so firmly established that participants rely at least partially on the prior expectations rather than the sensory evidence.

In our analysis, the three aspects of sound quality that emerged with prominent effect sizes were CLARITY, SMOOTHNESS, and FULLNESS. As defined in our study, CLARITY and SMOOTHNESS are strengths primarily associated with the digital sound, while FULLNESS is a distinct advantage of the vinyl recorded sound. Our estimations show how the respective expectations of vinyl and mp3 sound qualities operate on participants’ judgement by lessening and strengthening the perception of the underlying music format in the direction of vinyl vs. mp3-related sound qualities. Specifically, we found negative expectation effects of mp3 and vinyl upon the mp3-played format in that the expectation of mp3 made the perceived sound quality even lesser related to the vinyl quality of FULLNESS and that the expectation of vinyl resulted in a lessened relationship to the digital sound qualities of CLARITY and SMOOTHNESS. Similarly, we established positive expectation effects for vinyl and mp3 upon mp3 as the vinyl expectation resulted in a strengthened relationship with the vinyl quality of FULLNESS, and the mp3 expectation enhanced the association with the digital sound qualities of CLARITY and SMOOTHNESS.

These results should be conceived in the context that the participants could tease out the mp3-played song from the same song played on vinyl. Mp3s are a lossy music format, with the highest encoding possible at 320 kbps and the lowest at 32 kbps. As a comparison, A compact disc is encoded at 1,411 kbps. That the mp3 was encoded at the bitrate of 192 kbps makes our results even more compelling; even for this medium bitrate, and presumably wide gap in sound quality between vinyl and mp3, the expectation effect is found.

While it is true that analogue recordings may provide more accurate representations of recorded sound, the average music consumer does not necessarily have the audio equipment nor command the expertise to detect and gauge differences in nuances among the analogue and compressed digital formats. Despite this, there is a widespread belief that vinyl sounds better than other music formats. The takeaway from our results is that it is not the actual sound quality of vinyl alone that drives the preference, but rather the knowledge of vinyl’s better sound that impacts sound perception for the average music consumer. From a consumer judgement and decision-making standpoint and information processing dilemma, the knowledge of vinyl’s superior sound quality likely forms a salient heuristic that is easily accessible to the consumer and impacts the listening experience.

High-end equipment will most certainly produce a different listening experience between vinyl and compressed music formats. While the focus of this study was the average music consumer, a worthy extension is to explore the role of expectations on audiophiles. Based on previous research on expectation and wine tasting (Plassmann et al., 2008), we expect expectation to play a less salient role on audiophiles than the average music consumer. Beyond the person’s audiophile orientation, the results may differ depending on music interest and genre. In this exploratory work, we did not include contenders of lossless streaming music. Estimating the effect of brand expectation would yield additional insights into how expectations regarding factual vs. non-factual differences in sound quality operate.