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 All of this, however, is decades out-of-date.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.

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*** 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.

Compared with compatriots of the same age, women with at least one sibling who died in childhood face 39% higher odds of having experienced at least one own-child death, or 7 percentage points at age 49

Intergenerational Persistence in Child Mortality. Frances R. Lu & Tom Vogl. NBER Working Paper 29810. March 2022. DOI 10.3386/w29810

Abstract: We study the intergenerational persistence of inequality by estimating grandmother-mother associations in the loss of a child, using pooled data from 119 Demographic and Health Surveys in 44 developing countries. Compared with compatriots of the same age, women with at least one sibling who died in childhood face 39% higher odds of having experienced at least one own-child death, or 7 percentage points at age 49. Place fixed effects reduce estimated mortality persistence by 47%; socioeconomic covariates explain far less. Within countries over time, persistence falls with aggregate child mortality, so that mortality decline disproportionately benefits high-mortality lineages.

US, UK, Germany: Workers feel as secure as they ever have in the last thirty years, partly because job insecurity is very cyclical and (pre-COVID) unemployment rates very low, but there is also no clear underlying trend towards increased subjective measures of job insecurity

Subjective Job Insecurity and the Rise of the Precariat: Evidence from the United Kingdom, Germany, and the United States. Alan Manning, Graham Mazeine. The Review of Economics and Statistics 1–45. May 12 2022. https://doi.org/10.1162/rest_a_01196

Abstract: There is a widespread belief that work is less secure than in the past, that an increasing share of workers are part of the “pprecariat”. It is hard to find much evidence for this in objective measures of job security, but perhaps subjective measures show different trends. This paper shows that in the US, UK, and Germany workers feel as secure as they ever have in the last thirty years. This is partly because job insecurity is very cyclical and (pre-COVID) unemployment rates very low, but there is also no clear underlying trend towards increased subjective measures of job insecurity. This conclusion seems robust to controlling for the changing mix of the labor force, and is true for specific sub-sets of workers.

JEL: J28

Dark Triad traits accelerate psychological violence toward romantic partners

Do the Dark Triad and psychological intimate partner violence mutually reinforce each other? An examination from a four-wave longitudinal study. Yuji Kanemasa, Yuki Miyagawa, Takashi Arai. Personality and Individual Differences, Volume 196, October 2022, 111714. https://doi.org/10.1016/j.paid.2022.111714

Abstract: Although cross-sectional research showed a correlation between the Dark Triad and intimate partner violence (IPV), it was unclear whether the Dark Triad facilitated violence toward partners or whether violent acts fostered the dark personality traits. We aimed to statistically clarify the causal relationships between the Dark Triad traits and psychological IPV perpetration in romantic relationships. We conducted a longitudinal study every four months for one year across four waves in a sample of individuals who were currently in romantic relationships. A total of 1392 individuals (Mage = 29.73, SDage = 5.92) who dated the same partners throughout completed the four waves of surveys that measured the Dark Triad traits, psychological IPV, and demographic variables. Cross-lagged panel models revealed consistent patterns in the associations between each of the Dark Triad traits and psychological IPV perpetration throughout the four waves. Machiavellianism and psychological IPV perpetration increased each other. Psychological IPV perpetration reinforced the tendency for psychopathy, but not vice versa. Narcissism promoted future psychological IPV perpetration, but not vice versa. Our study illustrates how the Dark Triad traits accelerate psychological violence toward romantic partners and how such violence fosters the dark side of personality.

Keywords: Dark Triad traitsPsychological intimate partner violenceRomantic relationshipsCross-lagged panel modelsLongitudinal research

Women are less accepting than men of higher-ranked same-sex individuals; more generally however, women and men prefer male bosses

Human Females as a Dispersal-Egalitarian Species: A Hypothesis about Women and Status. Joyce F. Benenson. Adaptive Human Behavior and Physiology, May 21 2022. https://link.springer.com/article/10.1007/s40750-022-00191-x

Abstract

Objectives: A paradox exists in research on girls and women. On the one hand, they behave in a more egalitarian fashion than their male counterparts. On the other hand, status increases their own and their children’s survival.

Methods: Evidence from non-human primates can help reconcile these findings. In species that do not reside with female kin for life, females are relatively egalitarian and individualistic. They typically do not cooperate or engage in direct competition and exhibit little tolerance for status differentials.

Results and Conclusions: Women follow this pattern. While a husband’s status and her female relatives’ support enhance a woman’s status and reproductive success, her own actions too influence her access to resources and allies. Evidence on girls’ and women’s same-sex competition and quests for status supports the hypothesis that human females inhabit dispersal-egalitarian communities in which competition is avoided, an egalitarian ethos prevails, competitive behavior is disguised, and status differentials are not tolerated.

Personality stability increases mostly until 25 yo; emotional stability increased consistently and more substantially across the lifespan than currently believed

Bleidorn, Wiebke, Ted Schwaba, Anqing Zheng, Christopher J. Hopwood, Susana Sosa, Brent Roberts, and Daniel A. Briley. 2022. “Personality Stability and Change: A Meta-analysis of Longitudinal Studies.” PsyArXiv. May 20. doi:10.31234/osf.io/eq5d6

Abstract: Past research syntheses provided evidence that personality traits are both stable and changeable throughout the lifespan. However, early meta-analytic estimates were constrained by a relatively small universe of longitudinal studies, many of which tracked personality traits in small samples over moderate time periods using measures that were only loosely related to contemporary trait models such as the Big Five. Since then, hundreds of new studies have emerged allowing for more precise estimates of personality trait stability and change across the lifespan. Here, we updated and extended previous research syntheses on personality trait development by synthesizing novel longitudinal data on rank-order stability (total k = 189, total N = 178,503) and mean-level change (total k = 276, N = 242,542) from studies published after January 1st 2005. Consistent with earlier meta-analytic findings, the rank-order stability of personality traits increased significantly throughout early life before reaching a plateau in young adulthood. These increases in stability coincide with mean-level changes in the direction of greater maturity. In contrast to previous findings, we found little evidence for increasing rank-order stabilities after age 25. Moreover, cumulative mean-level trait changes across the lifespan were slightly smaller than previously estimated. Emotional stability, however, increased consistently and more substantially across the lifespan than previously found. Moderator analyses indicated that narrow facet-level and maladaptive trait measures were less stable than broader domain and adaptive trait measures. Overall, the present findings draw a more precise picture of the lifespan development of personality traits and highlight important gaps in the personality development literature.

In the dating market, people compete ferociously for mates with qualities that do not increase one’s chances of romantic happiness

Adapted from Don't Trust Your Gut: Using Data to Get What You Really Want in Life, by Seth Stephens-Davidowitz. Wired, May 2022. https://www.wired.com/story/data-marriage-behavior-love-psychology-romance/

Whom shoud you marry?

This may be the most consequential decision of a person’s life. The billionaire investor Warren Buffett certainly thinks so. He calls whom you marry “the most important decision that you make.”

[...]

She recruited a large number of scientists who had collected data on relationships—her team ended up including 85 other scientists—and was able to build a dataset of 11,196 heterosexual couples.

The size of the dataset was impressive. So was the information contained in it. For each couple, Joel and her team of researchers had measures of how happy each partner reported being in their relationship. And they had data on just about anything you could think to measure about the two people in that relationship.

The researchers had data on:

demographics (e.g., age, education, income, and race)

physical appearance (e.g., How attractive did other people rate each partner?)

sexual tastes (e.g., How frequently did each partner want sex? How freaky did they want that sex to be?)

interests and hobbies

mental and physical health

values (e.g., their views on politics, relationships, and child-rearing)

and much, much more.

Further, Joel and her team didn’t just have more data than everybody else in the field. They had better statistical methods. Joel and some of the other researchers had mastered machine learning, a subset of artificial intelligence that allows contemporary scholars to detect subtle patterns in large mounds of data. One might call Joel’s project the AI Marriage, as it was among the first studies to utilize these advanced techniques to try to predict relationship happiness.

After building her team and collecting and analyzing the data, Joel was ready to present the results—results of perhaps the most exciting project in the history of relationship science.

So, can Samantha Joel—teaming up with 85 of the world’s most renowned scientists, combining data from 43 studies, mining hundreds of variables collected from more than 10,000, and utilizing state-of-the-art machine learning models—help people pick better romantic partners?

No.

The number one—and most surprising—lesson in the data, Samantha Joel told me in a Zoom interview, is “how unpredictable relationships seem to be.” Joel and her coauthors found that the demographics, preferences, and values of two people had surprisingly little power in predicting whether those two people were happy in a romantic relationship.

And there you have it, folks. Ask AI to figure out whether a set of two human beings can build a happy life together and it is just as clueless as the rest of us.

Well... that sure seems like a letdown. Does data science really have nothing to offer us in picking a romantic partner, perhaps the most important decision that we will face in life?

Not quite. In truth, there are important lessons in Joel and her coauthors’ machine learning project, even if computers’ ability to predict romantic success is worse than many of us might have guessed.

For one, while Joel and her team found that the power of all the variables that they had collected to predict a couple’s happiness was surprisingly small, they did find a few variables in a mate that at least slightly increase the odds you will be happy with them. More important, the surprising difficulty in predicting romantic success has counterintuitive implications for how we should pick romantic partners.

Think about it. Many people certainly believe that many of the variables that Joel and her team studied are important in picking a romantic partner. They compete ferociously for partners with certain traits, assuming that these traits will make them happy. If, on average, as Joel and her coauthors found, many of the traits that are most competed for in the dating market do not correlate with romantic happiness, this suggests that many people are dating wrong.

[...]

If I had to sum up, in one sentence, the most important finding in the field of relationship science, thanks to these Big Data studies, it would be something like this (call it the First Law of Love): In the dating market, people compete ferociously for mates with qualities that do not increase one’s chances of romantic happiness.

[...]

In mammalian societies... How reproductive control promotes social control

The eco-evolutionary landscape of power relationships between males and females. Eve Davidian et al. Trends in Ecology & Evolution, May 18, 2022. https://doi.org/10.1016/j.tree.2022.04.004

Highlights

. Inequality in the degree of control (or ‘power’) that members of one sex exert over members of the other sex is a pervasive characteristic of mammalian societies, including our own.

. The study of the drivers of male–female power relationships has been impeded by methodological limitations and a lack of conceptual embedding in theories of sexual conflict, sexual selection and social evolution.

. Recent evidence challenges long-standing views by showing that (i) power ranges along a continuum from strictly male- to strictly female-dominated animal societies and (ii) intersexual power relationships are not fixed attributes of species.

. Here we break with dichotomist and static approaches to adopt a dynamic, theory-driven framework that provides a better understanding of the power struggles between the sexes, and how these relate to the social and mating system of a species.

Abstract: In animal societies, control over resources and reproduction is often biased towards one sex. Yet, the ecological and evolutionary underpinnings of male–female power asymmetries remain poorly understood. We outline a comprehensive framework to quantify and predict the dynamics of male–female power relationships within and across mammalian species. We show that male–female power relationships are more nuanced and flexible than previously acknowledged. We then propose that enhanced reproductive control over when and with whom to mate predicts social empowerment across ecological and evolutionary contexts. The framework explains distinct pathways to sex-biased power: coercion and male-biased dimorphism constitute a co-evolutionary highway to male power, whereas female power emerges through multiple physiological, morphological, behavioural, and socioecological pathways.

How reproductive control promotes social control

Here we propose that the degree of male and female reproductive control determines whether and how members of each sex can empower themselves socially, with respect to access to nonreproductive resources. We further illustrate how the mechanism by which power emerges may influence its durability.

 Coercion: an evolutionary highway to male power

Male coercive reproductive control is facilitated by large male-biased sexual dimorphism in size and weaponry, which is typical of contest-based mating systems, and includes most polygynous and some polygynandrous societies [

37.

,

44.

,

57.

] (Figure 1). In these systems, males often extend their use of coercion to dominate females when competing over nonreproductive resources. Large males may further reinforce intersexual asymmetries in coercive potential and limit female empowerment by controlling their social environment and preventing them from recruiting social allies (Box 2). The tight association between the pervasive use of coercion by males and male-biased sexual dimorphism likely emerges from a co-evolutionary feedback with the mating system (Figure 2). When males gain reproductive pay-offs from aggressively monopolising females against competitors, this will often (i) promote contest-based competition between males; (ii) subsequently drive the evolution of male-biased sexual dimorphism [

36.

,

37.

], which will (iii) promote male coercive reproductive control over females; and (iv) drive male social empowerment and dominance over females [

19.

,

36.

,

44.

]. This will (v) ultimately close the loop by strengthening male reproductive control over females [

38.

,

39.

,

44.

,

57.

]. When female resistance strategies fail to prevent or disrupt this potent self-reinforcing loop, it may catalyse the emergence and maintenance of male-biased power over evolutionary times. This likely explains why males often exert both high reproductive and social control over females in contest-based mating systems (Figure 1), and why contest-based systems are widespread among mammals. In addition, female strategies may sometimes reinforce rather than disrupt the loop favouring male power. For example, where males already have high reproductive control and females cannot mate promiscuously to dilute paternity, they may instead concentrate paternity to seek paternal protection in response to infanticidal threats [

58.

]. Such paternity concentration strategies may contribute to locking females into male-dominated societies.

Figure 2Eco-evolutionary pathways to male and female empowerment in mammals.

• PPT

 Why the coercive pathway is not the females’ way

A similar coercive co-evolutionary pathway is unlikely to drive female social empowerment because mammalian species in which females concurrently exhibit contest-based intrasexual competition to monopolise access to multiple males and larger body sizes are currently unreported [

59.

,

60.

]. In some species, reproductive competition may be most intense among females; yet, contrary to what would be expected for this co-evolutionary pathway, these species either exhibit sexual monomorphism, as in the polyandrous moustached tamarins (Saguinus mystax) [

57.

] and cooperatively breeding meerkats [

30.

] (Figure 1A), or male-biased size dimorphism as in Damaraland mole rats (Fukomys damarensis) [

60.

]. This apparent paradox probably reflects inherent differences in the life history and modality of intrasexual competition in females and males [

60.

]. Female mammals often compete using subtle forms of coercion – for example, using threats and agonistic signals – which do not select for increased body size and weaponry. There are at least three reasons for this: first, theory predicts avoidance of overt aggression for the sex that faces highest costs of offspring production [

61.

]; second, the incentive for females to engage in physical contest may be low because sharing resources is often less costly for females than for males; third, mammalian females are usually philopatric and thus predominantly compete with close female kin, with whom they may avoid engaging in costly contests [

60.

]. These insights emphasise key differences in the pathways to female and male power (Figure 2), in particular that a large body size and coercion are not prerequisites for female empowerment.

 Female social empowerment from leverage based on sex

When females retain some reproductive control – usually in species with moderate sexual size dimorphism as in monogamous, polyandrous, and scramble-based polygynandrous species (Figure 1) – they can trade copulations for resources or services that males can provide, such as protection for themselves or their offspring against conspecifics or predators. Yet, such leverage is usually restricted to periods of female sexual receptivity and thereby only confer short-term social empowerment to females, as in some mouse lemurs (Microcebus spp.) where female social control over males is more pronounced during the breeding season [

62.

,

63.

]. Leverage-based power may therefore explain female social empowerment over males in species where males are nonpermanent residents and join groups only during the mating season, as in rock hyraxes [

17.

]. In species living in permanent groups where males and females maintain long-term, differentiated social relationships, females can extend their leverage beyond the receptive period. This strategy may durably promote cooperative behaviour or inhibit aggression from males through mating markets, as in long-tailed macaques (Macaca fascicularis) [

64.

] and Guinea baboons (Papio papio) [

65.

]. Leverage can then represent a potent source of social control that may, even under male-biased dimorphism, allow females to manipulate the social rank of subordinate males, as in vervet monkeys [

32.

], or to influence male social and competitive relationships, as in bonobos (Box 3). Similar to males, but through a different mechanism, increased social control by females may subsequently reinforce female reproductive control by facilitating their resistance to unwanted solicitations in a positive feedback loop (Figure 2).

 Female social empowerment from mate choice

When female reproductive control enables them to exercise precopulatory mate choice, they may select male traits (e.g., social deference, cooperative personalities, or a smaller body size) that may, over evolutionary time, increase female social control in a process described by the ‘docile male’ hypothesis [

35.

]. In bonobos, the related ‘self-domestication’ hypothesis posits that selection for nonaggressive males, which may partly result from female choice, has contributed to the contrasts in morphology, physiology, behaviour, and cognition between male bonobos and chimpanzees (Pan troglodytes) [

24.

]. Empirical evidence of female mate choice for such male traits is scarce in mammals, however [

12.

]. Female preferences for males with whom they are socially bonded have been reported [

66.

,

67.

], but may reflect leverage rather than choice for male traits that are relevant to intersexual power. Alternatively, female mate choice can promote intersexual power asymmetries indirectly. For example, in spotted hyenas, female reproductive control and mate preferences drive male dispersal [

68.

], which decreases the number of social allies that males can recruit and thus reduces male social control [

28.

].