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. https://doi.org/10.1002/ajp.23394

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.

Highlights

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. Noëlle Gunst, Jean-Baptiste Leca, Paul L. Vasey. American Journal of Primatology, May 25 2022. https://doi.org/10.1002/ajp.23395

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. https://doi.org/10.1080/00224499.2022.2071411

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/osf.io/9gq5e

Abstract

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. https://onlinelibrary.wiley.com/doi/10.1002/hbm.25905

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.

4 DISCUSSION

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 | https://doi.org/10.3389/fpsyg.2022.873517

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.

Discussion

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.

Alex Tabarrok's review of Nate Hilger's The Parent Trap

The Parent Trap–Review of Hilger. Review by Alex Tabarrok, Marginal Revolution, May 25 2022. https://marginalrevolution.com/marginalrevolution/2022/05/the-parent-trap-review-of-hilger.html

Nate Hilger’s has written a brave book. Almost everyone will find something to hate about The Parent Trap. Indeed, I hated parts of it. Yet Hilger is willing to say truths that are often not said and for that I would rather applaud than cancel.

Hilger argues that the problems of poverty, pathology and inequality that bedevil the United States are not primarily due to poor schools, discrimination, or low incomes per se. The primary cause is parents: parents who are unable to teach their children the skills that are necessary to succeed in the modern world. Since parents can’t teach the necessary skills, Hilger calls for the state to take their place with a dramatic expansion of not just child care but collective parenting.

Let’s unpack some details. Begin with schooling. It’s very common to bemoan the state of schools in the “inner city” or to complain about “local financing” which supposedly guarantees that poor counties will have underfunded schools. All of this, however, is decades out-of-date.

A hundred years ago there really were massive public-school resource gaps by class and race. These days, however, state and federal spending play a larger role than local property tax revenue and distribute educational resources more progressively….In fact, when we include federal aid, 42 states spent more on poor school districts than on rich school districts in 2012. The same pattern holds between schools within districts

….The highest spending districts are large urban centers such as New York City, Boston and Baltimore. These cities spend large sums to educate rich and poor children alike. p. 10-11

Hilger is correct. No matter what you saw on The Wire, Baltimore spends more than sixteen thousand dollars per student, among the highest in the nation in large school districts and above average for the nation as a whole. Public schools are quite egalitarian in funding with any bias running towards more funding for poorer districts.

Full review with charts, etc., at the link above

Atheism may serve as a cue to the endorsement of less committed mating strategies, which, in turn, prompts concerns about atheists’ trustworthiness and approval in trust domains

Testing a perceived uncommitted mating strategy account for atheist distrust and marriage disapproval. Joshua T. Lambert, William Hart & Charlotte Kinrade. Current Psychology, May 19 2022. https://link.springer.com/article/10.1007/s12144-022-03151-6

Abstract: Recent research suggests presumptions about atheists’ uncommitted mating strategy causes atheists to seem less trustworthy, and that people who are more religious or espouse less agreeable attitudes toward uncommitted mating (i.e., more restricted sociosexual attitudes) tend to harbor greater anti-atheist attitudes. We provided additional tests of these ideas and addressed whether they could extend to discrimination against atheists in a “high-trust domain:” likelihood of granting approval to marry one’s adult child. An MTurk sample of U.S. parents (N = 301) self-reported their religiosity and sociosexual attitudes, then were randomly assigned to a condition wherein they read about their adult child’s fiancé who was either depicted as an atheist or devoted Christian. Participants reported their likelihood of approving of their child marrying the fiancé and estimated the fiancé’s committed mating strategy, trustworthiness, and dark personality characteristics. Participants with high religiosity presumed an atheist (vs. devoted Christian) fiancé endorsed a less committed mating strategy, which, apart from presumptions about the fiancé’s standing on dark personality characteristics, was associated with (a) perceiving the atheist as less trustworthy and (b) indicating less approval for their child marrying an atheist. Broadly, the research extends theorizing on how atheism relates to perceived threats to moral values and discrimination.

Why is the marriage rate falling in East Asia? College graduate women prefer less patriarchal men, i.e. men whose mothers worked or non-Japanese if they’re in the US; given their shortage, educated East Asian women remain single

Housewife, “Gold Miss,” and Equal: The Evolution of Educated Women’s Role in Asia and the U.S. Jisoo Hwang. May 2022. https://drive.google.com/file/d/1WTG_ynawyt2nExsrDEnw9JMkgVvB1gqd/view

Abstract: The fraction of U.S. college graduate women who ever marry has increased relative to less educated women since the mid-1970s. In contrast, college graduate women in developed Asian countries have had decreased rates of marriage, so much so that the term “Gold Misses” has been coined to describe them. This paper argues that the interaction of rapid economic growth in Asia combined with the intergenerational transmission of gender attitudes causes the “Gold Miss” phenomenon. I present a simple dynamic model then test its implications using U.S. and Asian data on marriage and time use.

JEL: J12, D10, Z10.

Keywords: Marriage, education, female labor force participation, cultural transmission.

There is a widespread belief that Republicans and Democrats are worlds apart with respect to their preferences for redistribution

Nathan, Brad, Ricardo Perez-Truglia, and Alejandro Zentner. 2022. "Is the Partisan Divide Real? Polarization in Preferences for Redistribution." AEA Papers and Proceedings, 112: 156-62.May 2022. DOI: 10.1257/pandp.20221070

Abstract: There is a widespread belief that Republicans and Democrats are worlds apart with respect to their preferences for redistribution. However, is that partisan divide real? In this paper, we discuss evidence from the General Social Survey and a tailored survey. We also discuss a revealed-preference measure constructed with administrative data. We conclude that the partisan divide is more nuanced than previously thought.

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How much income redistribution should happen, on a scale of 1 to 7: "Perhaps the most striking evidence of polarization is that in the 1–7 scale, the modal response among Republicans is 1, and the modal response among Democrats is 7."

"One question in the online survey [...] asks about property taxes instead of federal taxes: “Do you consider the amount of property taxes you pay to be too low, about right, or too high?” [T]he share of Democrats responding that property taxes are too high (36.9 percent) is not much lower than the corresponding share of Republicans (42.9 percent)."

"[T]he desired tax reduction is 28.46 percent for Republicans versus 23.42 percent for Democrats."

"Democrats want to assign 25.92 percent of property taxes to the poorer household, and Republicans want to assign 25.71 percent to the poorer household".

"It is possible that the differences between Democrats and Republicans lie mostly in the taxation of the very wealthy. [But t]he results indicate that as the difference in home values increases, the modal respondent still desires proportional taxes."

"Why are Republicans and Democrats so different according to the survey data from Figure 1, yet so similar according to their tax protest behavior? A simple explanation is based on the aphorism that “everyone’s a Republican on tax day.” That is, Republicans and Democrats may say that they feel differently about income redistribution, but those differences disappear when facing real, high-stakes choices. We posit a different, yet still simple, explanation: partisan differences in preferences for redistribution are exaggerated by some, but not all, survey questions."

It is more plausible that better-adjusted individuals are more likely to get married than the social causation hypothesis (marriage causes improvement in mental & physical health)

Huntington, C., Stanley, S. M., Doss, B. D., & Rhoades, G. K. (2022). Happy, healthy, and wedded? How the transition to marriage affects mental and physical health. Journal of Family Psychology, 36(4), 608–617. https://doi.org/10.1037/fam0000913

Abstract> Decades of research have documented the apparent health benefits of marriage, but the dynamics of how health may change across the transition to marriage are not fully understood. In two studies, we compared being unmarried or married on several indices of mental and physical health. In Study 1, we used a national sample of 1,078 individuals in different-sex relationships who completed surveys by mail. Compared with those who were cohabiting or dating, married individuals generally reported better mental and physical health than those in less committed relationships, and most differences remained when controlling for putative selection factors. Study 2 used longitudinal data from the participants in the Study 1 sample who later married (N = 168) to study changes within individuals over the transition to marriage on the same indicators. Six waves of mailed surveys spanning 20 months were employed. Findings of Study 2 indicated that although some indicators of mental and physical health were improving up until the point of marriage, these indicators then stabilized or began to decline, with women experiencing these declines more than men. Findings are more consistent with selection effects (i.e., better-adjusted individuals are more likely to get married) than social causation effects (i.e., marriage causes improvements in mental and physical health) and suggest that if marriage does have a causal effect on well-being in the short term, it may actually manifest in the lead-up to the wedding. Implications of these findings are discussed.

Intelligent people are hardly any more likely to positively evaluate intelligence in their partners

Eastwick, P. W., Finkel, E. J., & Joel, S. (2022). Mate evaluation theory. Psychological Review, May 2022. https://doi.org/10.1037/rev0000360

Abstract: There are two unresolved puzzles in the literature examining how people evaluate mates (i.e., prospective or current romantic/sexual partners). First, compatibility is theoretically crucial, but attempts to explain why certain perceivers are compatible with certain targets have revealed small effects. Second, features of partners (e.g., personality, consensually rated attributes) affect perceivers’ evaluations strongly in initial-attraction contexts but weakly in established relationships. Mate Evaluation Theory (MET) addresses these puzzles, beginning with the Social Relations Model postulate that all evaluative constructs (e.g., attraction, relationship satisfaction) consist of target, perceiver, and relationship variance. MET then explains how people draw evaluations from mates’ attributes using four information sources: (a) shared evolved mechanisms and cultural scripts (common lens, which produces target variance); (b) individual differences that affect how a perceiver views all targets (perceiver lens, which produces perceiver variance); (c) individual differences that affect how a perceiver views some targets, depending on the targets’ features (feature lens, which produces some relationship variance); and (d) narratives about and idiosyncratic reactions to one particular target (target-specific lens, which produces most relationship variance). These two distinct sources of relationship variance (i.e., feature vs. target-specific) address Puzzle #1: Previous attempts to explain compatibility used feature lens information, but relationship variance likely derives primarily from the (understudied) target-specific lens. MET also addresses Puzzle #2 by suggesting that repeated interaction causes the target-specific lens to expand, which reduces perceivers’ use of the common lens. We conclude with new predictions and implications at the intersection of the human-mating and person-perception literatures.

Rolf Degen summarizing... There are veritable yea-sayers who tend to answer affirmatively to questions, regardless of context

Who's a yea-sayer? Habitual trust and affirmative response behaviour. Ann-Christin Posten, Janina Steinmetz- European Journal of Social Psychology. February 3 2022. https://doi.org/10.1002/ejsp.2839

Abstract: We test the hypothesis that people who habitually trust others respond more affirmatively to questions (i.e. acquiescence). Six studies explore whether people's habitual tendency to trust others translates into a general acquiescent response bias. By re-analysing large-scale cross-country data, Study 1 shows that participants’ level of habitual trust predicts agreement across multiple and diverse concepts. Studies 2a and 2b show that habitual trust predicts acquiescent responding in classic psychological questionnaires. Habitual trust likewise predicts behavioural acquiescence, such as an agreement to assign monetary awards to others (Study 3) and staying with the suggested default option in a real choice paradigm (Study 4). Furthermore, the relation between habitual trust and acquiescent responding holds across different communication contexts (Study 5). These results imply that habitual trust predicts how individuals respond to questionnaire items that are used across a variety of research domains.

12 GENERAL DISCUSSION

Habitual trust entails the motivation to affiliate with others (e.g. Evans & Revelle, 2008; Slepian et al., 2012) and the cognitive tendency to think in congruent terms (Kleiman et al., 2015; Mayo, 2015; Mayo et al., 2014; Posten & Mussweiler, 2013). Both a motivation to affiliate (Steinmetz & Posten, 2017) and a congruent thinking style should foster answering affirmatively to questions irrespective of the question content. Across six studies, we demonstrate that, indeed, people who are habitually trusting answer more affirmatively. Using four different measures of habitual trust, six studies consistently demonstrated that people who are habitually trusting show an acquiescent response bias. Habitual trust predicted people's acquiescent responding to questions addressing various aspects of life (Study 1), response scales as used in classic psychological questionnaires (Studies 2a and 2b) and when evaluating others’ work determining their monetary outcomes (Study 3). Over and above response scales, individual levels of habitual trust also predicted the choice of default options (Study 4) and agreement in a forced-choice setting, in which participants could only agree or disagree (Study 5). The relation of habitual trust and acquiescence held across responses to ingroup or outgroup members (Study 5). Notably, the relation even showed in contexts that should be unaffected by social desirability concerns (Study 2b).

12.1 Alternative explanations and limitations

Our approach of using a variety of acquiescence measures might have limitations. Specifically, the correlations of the habitual trust and acquiescence measures differ between our Studies 1–2b that use more traditional survey questions to assess acquiescence (rs between .248 and .314) and our Studies 3–5 that use more behavioural manifestations of acquiescence (rs between .127 and .170). Thus, the relation between habitual trust and acquiescence might be more pronounced (and thus potentially more problematic for researchers) who use survey batteries, whereas more behavioural measures might be less affected. The smaller correlations between habitual trust and such behavioural measures might stem from the fact that participants might have been aware of the consequences of their responses for others (Study 3) and for the self (Study 4). This awareness might have increased the motivation to respond accurately, which might reduce but not fully eliminate acquiescence. Such awareness of consequences might be reduced when people respond to survey questions. Future research could test whether instructions that highlight the importance of surveys for public policy or for research would reduce the relation between habitual trust and acquiescence.

One might speculate whether the relation between habitual trust and acquiescence is driven by an underlying relation between habitual trust and the content of the questions that we used to assess acquiescence. Indeed, there might be some ‘true’ relation between habitual trust and the content of some questions that is not attributable to acquiescence, for example, on the interdependence subscale of the acquiescence measure in Studies 2a and 2b (Zeffane, 2017). Whereas there might be a ‘true’ relation between habitual trust and the content of some items in acquiescence measures, such a relation cannot explain our findings as a whole. For one, we measured acquiescence in a variety of ways across our studies. Specifically, in Studies 1–2b, we measured acquiescence as the responses to traditional survey questions (i.e. the WVS and the Singelis scale). It is unlikely that habitual trust relates to all the various concepts tested in the WVS or relates to interdependence and independence at the same time. For another, we used more behavioural measures of acquiescence in several studies that had no apparent overlap with habitual trust. For example, in Study 4, participants indicated their binary preference to stay with a default ad, without measuring any trust-related personality or values questions. In Study 5, we measured acquiescence as a binary choice between judging factual statements as true versus false. The measures in Studies 4 and 5 capture not a particular psychological content but a simple choice or judgement.

An alternative explanation for the observed correlation between habitual trust and acquiescence could be that this correlation is driven by trait agreeableness (Costa & McCrae, 2008). However, whereas agreeableness might well be related to acquiescence (Hibbing et al., 2019), the trust sub-facet of agreeableness could be one of the drivers of such a relation. With the exception of compliance, the other subscales of agreeableness (i.e. altruism, straightforwardness, modesty and tender-mindedness) seem less likely to correlate with the measures of acquiescence that we used. For example, someone high in modesty might show less acquiescence on the scale in Studies 2a and 2b that measures positive traits and behaviour, for fear of being immodest. Compliance has indeed been shown to correlate with acquiescence (measured as deference; Schuman & Presser, 1996). Because of this finding and our findings that habitual trust correlates with acquiescence, we would expect these two sub-facets of agreeableness to be the main drivers of an observed correlation between the entire agreeableness scale and an acquiescence measure. Thus, we focus on the sub-facet habitual trust instead of the entire agreeableness scale.

We base our hypothesis on motivational and cognitive mechanisms accompanying habitual trust that foster acquiescence. However, there might be more parsimonious explanations for our findings. First, perceiving a person as trustworthy often means also to perceive the person as similar to oneself (Farmer et al., 2014; Posten & Mussweiler, 2019). Similarity in turn leads to assimilation (Mussweiler, 2003), and thus, potentially, to affirmative answering. Second, trusting a person could induce halo effects (Nisbett & Wilson, 1977) by attributing generally positive characteristics to the counterpart, for instance being knowledgeable in a quiz (such as in Study 5). However, these alternative accounts would not predict a relation between habitual trust and acquiescence in low-trust contexts (e.g. outgroup interactions in Study 5), in which the question asker is neither similar to the self nor (presumably) perceived particularly positively. As we find that habitual trust correlates with acquiescence also when interacting with less trustworthy others, these alternative accounts are unlikely to explain our findings.

One limitation of our findings is that we did not directly test the motivational and cognitive mechanisms we propose by which habitual trust influences acquiescence. However, on the basis of previous research, we expect that the motivational and cognitive consequences of habitual trust (e.g. Mayo, 2015) are also operant in the case of acquiescence. Future research should nevertheless determine under which circumstances motivational versus cognitive factors play a larger role in the relation between habitual trust and acquiescence.

12.2 Implications and future directions

Much research has been done to identify, quantify and reduce acquiescent response biases (Krautz & Hoffmann, 2018). Many of these efforts are time-costly to administer (Baumgartner & Steenkamp, 2001; Couch & Keniston, 1960). Other approaches require creating additional items, which incur potential problems caused by common method variance (Podsakoff, 2003), or are limited to knowledge-based items (Krautz & Hoffmann, 2018). Within these approaches, most research has focused on response biases that originate from cultural differences (Krautz & Hoffmann, 2018; Marin et al., 1992).

Unlike existing approaches, the present research focuses on the detection of individuals who are more likely to acquiesce. We show that habitual trust correlates with acquiescence within a given culture (Studies 2–5: US-based MTurk workers and German students) and controlling for country differences (Study 1). Thus, we investigate individual differences that relate to acquiescence over and beyond cultural differences. Notably, habitual trust can be easily and reliably assessed by using short scales that consist of fewer than ten items (e.g. Costa & McCrae, 2008; Evans & Revelle, 2008; Rotter, 1967). With such scales, researchers could identify individuals or populations that score high on habitual trust. By assessing an individual's or a population's habitual trust, one may then have an indication of when the use of––however imperfect––existing corrective measures against acquiescent responding might be especially necessary because the likelihood of acquiescent responding could be increased.

One may further speculate whether researchers should avoid signals of explicit trustworthiness in their studies and experiments. The participant recruitment process often capitalizes on trustworthiness cues, such as university logos and researcher titles, to increase participation rates. Although our studies do not test such an effect, one may wonder whether trustworthiness cues might, however, foster the researcher's perceived trustworthiness. Our results in Study 5 suggest that the more a researcher is perceived as trustworthy, the more participants might agree with their statements (and questions). Thus, future research could test whether recruitment materials that use trustworthy cues to attract participants increase acquiescence by increasing the perceived trustworthiness of the person asking the questions. If this is indeed the case, one implication would be to use trustworthiness cues in the recruitment flyers to increase participation rates, but to ensure that the actual questionnaire (e.g. web page or paper questionnaire) is designed in a more neutral manner, without explicit trustworthiness cues, as a means to reduce acquiescence.

Men Are Not Aware of and Do Not Respond to Their Female Partner's Fertility Status

Schleifenbaum, Lara, Ruben C. Arslan, Julia Stern, Tanja M. Gerlach, Larissa L. Wieczorek, Julie C. Driebe, and Lars Penke. 2022. “Men Are Not Aware of and Do Not Respond to Their Female Partner's Fertility Status: Evidence from a Dyadic Diary Study of 384 Couples.” PsyArXiv. May 23. doi:10.31234/osf.io/7xeca

Abstract: Understanding how human mating psychology is affected by changes in female cyclic fertility is informative for comprehending the evolution of human reproductive behaviour. Based on differential selection pressures between the sexes, men are assumed to have evolved adaptations to notice women’s within-cycle cues to fertility and show corresponding mate retention tactics to secure access to their female partners when fertile. However, previous studies suffered from methodological shortcomings and yielded inconsistent results. In a large, preregistered online dyadic diary study (384 heterosexual couples), we found no compelling evidence that men notice women’s fertility status (as potentially reflected in women’s attractiveness, sexual desire, or wish for contact with others) or display mid-cycle increases in mate retention tactics (jealousy, attention, wish for contact or sexual desire towards female partners). These results extend our current understanding of the evolution of women’s concealed ovulation and oestrus, and suggest that both might have evolved independently.

When our mind misjudges because we have principles, not like others: Hosting the homeless in a hotel is bad, leaving them in the streets is sanity

Alex Tabarrok on this (Politico, Feb 4 2022, https://www.politico.com/news/2022/02/04/new-york-affordable-housing-program-00005049):

[...] 

 “There are very few hotels that physically could be converted and comply with the requirements of today’s zoning and building code without substantial, expansive reconstruction, partial removal or demolition,” said James Colgate, a land use partner at Bryan Cave Leighton Paisner LLP who has advised clients on zoning issues including the conversions of hotels. “That would increase the costs greatly.”

For example, a building’s elevators, doorways, or rooms may be slightly short of the size required for a residential structure. Residential buildings are also required to have a certain amount of rear-yard space that a hotel may not have.

“You would literally have to be chopping off part of the building,” Rosen said.

...The legislation dictates that each unit include a kitchen or kitchenette with a full-sized refrigerator, cooktop and sink — something Rosen said made utilizing the program “simply too expensive.”

“This is the classic case of the perfect being the enemy of the possible,” said Mark Ginsberg, a partner at the firm Curtis + Ginsberg Architects, which has worked on hotel conversions.***

Some advocates who pushed the creation of the program say those provisions were necessary to ensure it didn’t generate substandard housing.

Substandard housing compared to what? Living on the street?  And get this person.

“We didn’t want a program that cut corners to make it more palatable to developers,” said Joseph Loonam, housing campaign coordinator for the progressive advocacy group VOCAL-NY. “We wanted a program that centered the needs of homeless New Yorkers, which is true high quality affordable housing where they can have full autonomy and dignity.”

Well, they got what they wanted, the program wasn't palatable to developers as only one application has been received and none of the money spent. Thanks progressive advocacy group for centering the needs of homeless New Yorkers.

---

*** I disagree, it wasn't a failure of rational agents, it is a case of radicals who live well and whose job is to whine, regardless of the consequences for the homeless.

Introverts experienced less frequent and less enjoyable uplifts in their daily lives

Introversion and the Frequency and Intensity of Daily Uplifts and Hassles. Natasha N. DeMeo et al. Journal of Personality, May 14 2022. https://doi.org/10.1111/jopy.12731

Abstract

Introduction: There is reason to believe that introversion may relate to different patterns of negative and positive experiences in everyday life (“hassles” and “uplifts”), but there is little evidence for this based on reports made in daily life as events occur. We thus extend the literature by using data from ecological momentary assessments to examine whether introversion is associated with either the frequency or intensity of hassles and uplifts.

Method: Participants (N=242) were community-dwelling adults (63% Black, 24% Hispanic; ages 25-65; 65% women) who completed baseline measures of personality and mental health, followed by reports of hassles and uplifts 5x/day for 14 days. We present associations between introversion and hassles/uplifts both with and without controlling for mood-related factors (neuroticism, recent symptoms of depression and anxiety).

Results: Introversion was associated with reporting less frequent and less enjoyable uplifts, but not with overall hassle frequency or unpleasantness; exploratory analyses suggest associations with specific types of hassles.

Conclusion: Our results expand understanding of the role of introversion in everyday experiences, suggesting an overall association between introversion and uplifts (but not hassles, broadly) in daily life. Better understanding such connections may inform future research to determine mechanisms by which introversion relates to health.

Surprise, Gene Editing Can Change The Social Behavior of Animals in Unexpected Ways: "The counterintuitive findings tell us we need to start thinking about the actions of these receptors across entire circuits of the brain and not just in specific brain regions." :-(

CRISPR-Cas9 editing of the arginine–vasopressin V1a receptor produces paradoxical changes in social behavior in Syrian hamsters. Jack H. Taylor et al. Proceedings of the National Academy of Sciences, May 5, 2022. Vol. 119 | No. 19, e2121037119. https://doi.org/10.1073/pnas.2121037119

Popular version: https://www.sciencealert.com/crispr-gene-editing-can-even-alter-the-social-behavior-of-animals

Significance: Arginine–vasopressin (AVP) acting on V1a receptors (Avpr1as) represents a key signaling mechanism in a brain circuit that increases the expression of social communication and aggression. We produced Syrian hamsters that completely lack Avpr1as (Avpr1a knockout [KO] hamsters) using the CRISPR-Cas9 system to more fully examine the role of Avpr1a in the expression of social behaviors. We confirmed the absence of Avpr1as in these hamsters by demonstrating 1) a complete lack of Avpr1a-specific receptor binding throughout the brain, 2) a behavioral insensitivity to centrally administered AVP, and 3) an absence of the well-known blood-pressure response produced by activating Avpr1as. Unexpectedly, however, Avpr1a KO hamsters displayed more social communication behavior and aggression toward same-sex conspecifics than did their wild-type (WT) littermates.

Abstract: Studies from a variety of species indicate that arginine–vasopressin (AVP) and its V1a receptor (Avpr1a) play a critical role in the regulation of a range of social behaviors by their actions in the social behavior neural network. To further investigate the role of AVPRs in social behavior, we performed CRISPR-Cas9–mediated editing at the Avpr1a gene via pronuclear microinjections in Syrian hamsters (Mesocricetus auratus), a species used extensively in behavioral neuroendocrinology because they produce a rich suite of social behaviors. Using this germ-line gene-editing approach, we generated a stable line of hamsters with a frame-shift mutation in the Avpr1a gene resulting in the null expression of functional Avpr1as. Avpr1a knockout (KO) hamsters exhibited a complete lack of Avpr1a-specific autoradiographic binding throughout the brain, behavioral insensitivity to centrally administered AVP, and no pressor response to a peripherally injected Avpr1a-specific agonist, thus confirming the absence of functional Avpr1as in the brain and periphery. Contradictory to expectations, Avpr1a KO hamsters exhibited substantially higher levels of conspecific social communication (i.e., odor-stimulated flank marking) than their wild-type (WT) littermates. Furthermore, sex differences in aggression were absent, as both male and female KOs exhibited more aggression toward same-sex conspecifics than did their WT littermates. Taken together, these data emphasize the importance of comparative studies employing gene-editing approaches and suggest the startling possibility that Avpr1a-specific modulation of the social behavior neural network may be more inhibitory than permissive.

Discussion

Here, we report the successful use of CRISPR-Cas9 for the generation of Avpr1a KO Syrian hamsters. Through the breeding of a CRISPR-Cas9–edited founder and heterozygote progeny, we were able to successfully produce M and F Syrian hamsters completely lacking a functional Avpr1a gene. Avpr1a KO hamsters exhibited 1) a complete lack of Avpr1a binding throughout the brain, 2) insensitivity to the behavioral effects of centrally administered AVP, and 3) no changes in blood pressure in response to a peripherally injected Avpr1a agonist. Despite these expected changes, it is remarkable that Avpr1a KO hamsters expressed double the levels of odor-stimulated flank marking and aggression toward same-sex conspecifics than WTs.

Importantly, we showed haploinsufficiency in flank marking and aggressive behaviors and in Avpr1a binding in the brain, indicating that heterozygotes will be useful for investigating the effects of reduced, but not absent, Avpr1a expression. The translational relevance of behavioral genetic approaches should improve by increasing the variety of animal models and approaches, and these results demonstrate the utility of CRISPR-Cas9 gene editing in Syrian hamsters to interrogate gene function. Comparison of behavioral genetic data obtained from nontraditional model species with data obtained in KO mice (e.g., effects on aggression) provides important context that may help generalize findings to other rodents or to humans. During the generation and phenotyping of the hamsters described here, a KO was generated via CRISPR-Cas9 in prairie voles (27). Notably, these voles lack a functional Oxtr gene, and due to the relationship between Oxtrs and Avpr1a, they provide a useful comparison to our results in hamsters. In both species, CRISPR-Cas9 induced mosaics in edited animals. Mosaicism after Cas9-mediated gene editing is not uncommon (28–30), and, when generating a new KO model, it underscores the value of careful selective breeding of edited founders and descendants. Comparisons across species will likely provide new insight into the function and evolution of the various molecular substrates of behavior.

Flank marking plays a critical role in social communication in hamsters. M and F hamsters flank mark in response to odors of same-sex conspecifics or to hypothalamic injection of AVP without conspecific odors (9, 22, 31). In the present study, we again showed that intracerebroventricular (ICV) injection of AVP or a selective Avpr1a agonist in WT hamsters produced robust flank marking in odor-free environments; however, ICV injection of AVP or a selective Avpr1a agonist in Avpr1a KO hamsters had no effect on the expression of flank marking, demonstrating insensitivity of KOs to exogenous AVP. Surprisingly, we found that odor-stimulated flank marking was twofold higher in Avpr1a KO hamsters than in WT hamsters. This increase was specific to the presence of conspecific odor, as Avpr1a KO hamsters marked at the same low levels as WT hamsters in a clean cage. These findings indicate that Avpr1a activation is not necessary for the expression of odor-stimulated flank marking. Indeed, the present data are not alone in indicating that a disassociation between the number of Avpr1as and the expression of flank marking can occur. Housing in “summer-like” photoperiods (i.e., >12 h of light per day) dramatically increases the expression of hypothalamic Avpr1as compared with “winter-like” photoperiods (32). Interestingly, however, odor-stimulated and AVP-induced flank marking are expressed at the same levels, regardless of photoperiod (11, 33). The mechanisms responsible for the uncoupling of flank marking from the number of hypothalamic Avpr1as in short-photoperiod-exposed hamsters are not known, although photoperiod-induced compensatory changes in the response to neurochemical signals, such as serotonin or galanin, that can influence flank marking do not appear to be involved (34). Certainly, the investigation of the compensatory mechanisms that mediate the robust, odor-stimulated flank marking in Avpr1a KO hamsters is a necessary next step. Taken together, these data indicate that, although the presence of Avpr1as are necessary for exogenous AVP to induce flank marking, Avpr1as are not necessary for the expression of odor-stimulated flank marking; thus, it is clear that the neurochemical mechanisms regulating flank marking are more complex than previously thought.

Another intriguing and surprising finding emerged when we examined the result of eliminating functional Avpr1as on aggressive behavior. Previous studies have found that injection of AVP into the AH stimulates aggression in M hamsters and inhibits aggression in F hamsters and that injection of a selective Avpr1a antagonist into the AH inhibits aggression in M and stimulates aggression in F hamsters (13, 24, 25). Therefore, we predicted that the absence of Avpr1as would reduce aggression in M and increase aggression in F hamsters. As predicted, aggression was higher in Avpr1a KO F than in WTs, and aggression in heterozygote F was intermediate to that seen in KO and WT F. In Avpr1a KO M, however, aggression was unexpectedly higher than in heterozygotes or WTs. Indeed, aggression was twofold higher in M Avpr1a KO hamsters than it was in WT M. Thus, the elimination of functional Avpr1as eliminated the previously established sex differences in AVP-mediated aggression. These data are consistent with the hypothesis that Avpr1as have inhibitory effects on aggression in F and raise the possibility that the global loss of functional Avpr1as can increase aggression in M. Interestingly, aggression significantly increases in M and F hamsters exposed to short photoperiods compared with hamsters housed in long photoperiods (35, 36), under which there is a reduction of Avpr1as within key sites of the SBNN (32, 33). Similar to the increase in aggression seen in Avpr1a KO M hamsters, increased aggressiveness in short-photoperiod-exposed M hamsters does not depend on activation of Avpr1as (37). The short-photoperiod-induced increase in aggression may be the result of changes in the secretion of pineal melatonin that serve to increase aggression (38–42), and it will be interesting to investigate if M Avpr1a KOs have similar compensatory increases in melatonin secretion.

As discussed above, the diversity and complexity of social behaviors across species and among individuals is hypothesized to emerge from the functional interactions among the multiple nodes of SBNN circuitry, and not from the activity of its individual components (3, 5). Investigation of SBNN neurocircuitry has been restricted almost exclusively to studies of how individual nodes influence social behavior because of the inability to manipulate the entire circuit concurrently. Global KOs like those employed in the present study provide one approach, albeit an imperfect one, to manipulate key neurochemical signals across the entire circuit. The dramatic differences in aggression and social communication between the KO and WT hamsters seen in the present study were not predicted by studies employing pharmacological inhibition of Avpr1a activity within specific SBNN nodes. Therefore, elimination of Avpr1a activity throughout the entire SBNN circuit can impact social behavior very differently than does inhibiting Avpr1a activity in individual nodes of the circuit. As such, these data support the hypothesis that social behavior can be an emergent property coming from the interactions across nodes of the entire circuit. It is, however, important to emphasize the possibility that these differences could also be due to elimination of Avpr1as in regions outside the SBNN or as the result of developmental compensation. Nevertheless, the data obtained by using the KO approach suggest some fascinating questions about the putative functions of Avpr1a at a circuit level that are deserving of future study. For example, do Avpr1as operating across the circuit serve to inhibit the expression of at least some social behaviors, even though their activation in specific individual nodes can induce those behaviors? Are sex differences in aggression the result of sex differences in the effects of Avpr1a across the SBNN with activation of Avp1ar reducing aggression in M hamsters and enhancing aggression in F hamsters?

The phenotype of Avpr1a KO hamsters also differs greatly from the phenotype of Avpr1a KO mice, indicating that there are important species differences in Avpr1a function and/or compensatory mechanisms. M and F Avpr1a KO hamsters were more aggressive than were WT hamsters, whereas Avpr1a KO M mice display no differences in aggression from WTs (14). The increase in aggression in Avpr1a KO hamsters relative to WTs is informed by the concomitant increase in odor-stimulated flank marking, suggesting the possible existence of a hypersensitivity to and/or hyperresponsiveness to social olfactory stimuli in the main olfactory system (43). In contrast, Avpr1a KO mice exhibit reduced social investigation and impaired olfactory processing compared with WTs (14, 44). Taken together, these comparisons suggest that as CRISPR-Cas9 and related gene-editing technologies continue to be applied to new species and gene targets, more species-specific differences in gene function and developmental compensation will continue to be discovered. These data certainly emphasize the necessity of using species in addition to mice to interrogate the role of specific neurochemical signaling pathways in generating social behavior.

One critical aspect of genetic models is determining the influence of a gene (or its lack) throughout development (reviewed in ref. 45). It is difficult or impossible to separate the acute effects of eliminating a gene from its developmental effects in mammalian KO models, perhaps most notably in potential developmental compensation. For instance, it is possible that odor-stimulated flank marking in Avpr1a KO hamsters is “rescued” by other receptors. Two obvious candidates for compensation are Oxtr or Avpr1b. However, given that AVP, which binds and activates Oxtr and Avpr1b (46, 47), did not stimulate flank marking in KOs, this explanation is unlikely. Though we found no differences in Oxtr binding density in the brain nuclei examined, considering the strong link between the OT and AVP systems, it is possible that some developmental disruptions occurred in the Oxtr system in hamster Avpr1a KOs. Viral rescue strategies offer the potential to parse developmental and activational influences of Avpr1a KO (see ref. 48 for an example). The potential developmental consequences from the lack of Avpr1a will be an important target and consideration in future research using Avpr1a KO hamsters.

In conclusion, the unexpected behavioral phenotypes of Avpr1a KO Syrian hamsters reveal insight into the function of Avpr1as in facilitating social behavior. It was long thought that activation of Avpr1a was both necessary and sufficient for the expression of flank marking, but it now appears that flank marking can occur in the absence of Avpr1a activation in certain situations. This raises new questions regarding non-Avpr1a-mediated mechanisms of social communication. Gene-edited hamsters will provide an important tool in these future studies.