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.

].

14 measures shown produce sex-based sexuality differences: In every measure, replicated previous findings comparing heterosexual men & women; more diffs between heterosexual & bisexual men; patterns in women more pronounced, bisexuals play larger role

Sex and Sexual Orientation Differences in Sexuality and Mate Choice Criteria. Bogdan Kostic & John E. Scofield. Archives of Sexual Behavior, May 19 2022. https://link.springer.com/article/10.1007/s10508-021-02280-6

Abstract: Previous research has documented several reliable differences between men and women in terms of mate preferences regarding age, physical appearance, financial prospects, and more. However, most of the research has been on heterosexual populations. The current study attempted to further explore those differences in non-heterosexual populations. The project was part replication regarding heterosexual populations and part exploratory regarding non-heterosexual populations. The sample contained 3298 participants, including 1863 males (1675 gynephiles, 56 androphiles, 132 bisexuals) and 1435 females (1037 androphiles, 33 gynephiles, 365 bisexuals). Participants responded to questions about mate preferences in terms of good financial prospects, good looks, chastity, ambition/industriousness, youth/age, uncommitted sex, visual sexual stimuli, status, physical attractiveness, jealousy, and interest in short- versus long-term mating. Results replicated typical sex differences between heterosexual men and women in all measures we analyzed. We also found several instances when bisexual respondents were more different from heterosexual respondents than homosexual respondents (specifically regarding interest in uncommitted sex, the importance of chastity, and interest in short-term mating). Despite limitations in data collection, the results demonstrate that homosexual and bisexual individuals do not always form a heterogenous group.

Letters To A Spanish Youngster CCLXXI

Letters To A Spanish Youngster CCLXXI

[...]

Your Honor the little good wizard-magician,/Su Señoría el mago y brujito bueno,

I cry for being so far from You, person of excellent skills and fruitful work, and ibn Gabirol’s poems* allow me to survive these difficult times in which I do not have access to Your voice, much less Your beatiful features, which are a need for me to live a full life:/Lloro por estar tan lejos de Vd., persona de excelencia en sus habilidades y fructífero trabajo, y los poemas de ibn Gabirol me permiten sobrevivir en estos tiempos difíciles en que no tengo acceso a Su voz, no digamos sus forms bellas, que son necesarias para mí para vivir una vida plena:

[Cry for the friends that left/Llanto por los amigos ausentes]

[Me abandonó y alzóse hasta los cielos

[…]

Su llanto no te asombre; que fueron más copiosas

mis lágrimas, cual fueron mayores las angustias,

amigos, tras vosotros y a causa de vosotros:

angustias por los próximos que ahora están lejanos.

¿Acaso puede el hombre

vivir sin los amigos que estuvieron

soldados a la médula del alma?

¿Acaso encontrará descanso en esas noches

que cercan a sus ojos para impedirle el sueño?]

[Complaints for absence/Quejas por la ausencia]

[Llegaos hasta aquellos dos ramos de los mirtos

que tienen sus raíces en bálsamo y en mirra;

por el amor de un débil y enfermo, conjuradlos

para que en su clemencia

sobre mí se detengan un instante;

que sobre mí pasaron y hacia ellos mandé mi corazón].

[After Yonah departed/Tras la partida de Yoná]

[[un hombre]

al que prendido tienen

las sogas de los días de abandono[…]?

Se fueron sus amigos, quedó sin compañero;

entre los avatares del destino

suspira con lamento.

Que Dios no me recuerde si no os recordara;

mas al hacer memoria,

me agito en mi quejido y me conturbo.

Yo gimo por Yoná mi hermano, que ha partido;

y como si no hubiera ni espera ni esperanza,

en llanto me deshago.

Si aun antes de dejarme mi alma me dolía,

el día en que me hubo abandonado

voló como un milano.

[…]

Si hubieran sido sabios lso sabios, no te hubieran

dejado que partieras;

[…]

Sabio de corazón, inteligente,

perfecto, en él no hay tacha; cuando habla,

ni engaño ni mentira. […]]

[For Shemuel’s absence/Por la ausencia de Shemuel]

[Amigo de mi alma, Shemuel, por tu partida

turbado estoy, mis juicios temblorosos;

que el día de la marcha alzose con mi alma

haciéndose una sola con la tuya.

[…]

Por tanto yo resuello, mi alma se conturba,

me sacio del insomnio hasta la madrugada.

Aguardaré a que llegue el despuntar del alba

de aquellos que se fueron; entonces gozaremos

y nos deleitaremos en amores.]

[Longing/Añoranzas]

[¿Quién es esa tan galana

que cuando sus plantas pisan

va derramando y esparce

perfumes de sus sandalias?

Las joyas de sus collares

son como estrellas y lleva

imagen de sol y luna

encima de las lazadas

de su corona.

La gracia está en su cabeza,

la belleza está en su cara,

el esplendor en su cuerpo

y la gloria por sus haldas.

Como una gacela inclina

su cuello y torna la cara;

camina sin que yo vea

por dónde van sus cañadas.

[…]

Lleva mi paz a mi amado,

por favor, cuando te vayas,

que en los días y en las noches

de la tierra

mal soporto su añoranza.

Si Dios nos ha separado

se despertará el clamor

de su clemencia mirando

cómo son de abrumadoras

en las nochas las nostalgias.]

I am terribly bored with my life (I know that saying this is the opposite of generosity and genuine lack of selfishness :-( ), and only enjoy the time in which I am near You, following Your commands and wishes, and hearing Your voice :-) , which is so beautiful., my master.../Estoy muy, muy aburrido con la vida que llevo (sé que decir esto es lo opuesto a generosidad y la genuina falta de egoísmo :-( ) y solo disfruto del tiempo en que estoy con Vd., obedeciendo sus órdenes y deseos, y escuchando su voz :-) , que es tan hermosa, mi dueño...

Asking the gods for them to have some mercy and to allow me to see in the next days, O my only source of joy!, Yours faithfully/Rogando a los dioses que me muestren clemencia y me permitan verle en los próximos días, ¡oh mi única fuente de alegría!, Suyo fielmente

             a. r. ante Su Señoría,

--

Notes

* Adapted from Selected Poems of Solomon ibn Gabirol, translated by Peter Cole (Princeton, NJ: Princeton Univ. Press, 2001), & the Spanish version from Selomó ibn Gabirol—Poesía secular, by Elena Romero (Madrid: Alfaguara, 1978).