Saturday, May 21, 2022

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/

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.

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?


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.


. 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 [,,] (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 [,], which will (iii) promote male coercive reproductive control over females; and (iv) drive male social empowerment and dominance over females [,,]. This will (v) ultimately close the loop by strengthening male reproductive control over females [,,,]. 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 []. Such paternity concentration strategies may contribute to locking females into male-dominated societies.

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

 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 [,]. 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) [] and cooperatively breeding meerkats [] (Figure 1A), or male-biased size dimorphism as in Damaraland mole rats (Fukomys damarensis) []. This apparent paradox probably reflects inherent differences in the life history and modality of intrasexual competition in females and males []. 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 []; 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 []. 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 monogamouspolyandrous, 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 [,]. 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 []. 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) [] and Guinea baboons (Papio papio) []. 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 [], 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 []. 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) []. Empirical evidence of female mate choice for such male traits is scarce in mammals, however []. Female preferences for males with whom they are socially bonded have been reported [,], 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 [], which decreases the number of social allies that males can recruit and thus reduces male social control [].

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.

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.]


[¿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,



* 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).