Higher self-perceived attractiveness & fewer minor ailments predicted lower scores of Somatization, Obsessive–Compulsive, Interpersonal Sensitivity, Depression, Anxiety, Phobic Anxiety, Paranoid Ideation, Psychoticism

Self-Perceived Facial Attractiveness, Fluctuating Asymmetry, and Minor Ailments Predict Mental Health Outcomes. Javier I. Borráz-León, Markus J. Rantala, Severi Luoto, Indrikis A. Krams, Jorge Contreras-Garduño, Tatjana Krama & Ana Lilia Cerda-Molina. Adaptive Human Behavior and Physiology, Aug 31 2021. https://rd.springer.com/article/10.1007/s40750-021-00172-6

Abstract

Objective  Phenotypic markers associated with developmental stability such as fluctuating asymmetry, facial attractiveness, and reports of minor ailments can also act as indicators of overall physical health. However, few studies have assessed whether these markers might also be cues of mental health. We tested whether self- and other-perceived facial attractiveness, fluctuating asymmetry, and minor ailments are associated with psychopathological symptoms in a mixed sample of 358 college students, controlling for the effects of body mass index, age, and sex.

Methods  We applied the Symptom Checklist-90-Revised (SCL-90-R) questionnaire to assess psychopathological symptoms, a battery of questionnaires about self-perceptions of facial attractiveness, and gathered information about the number of previous minor ailments as well as demographic data. Other-perceived attractiveness was assessed by an independent mixed sample of 109 subjects. Subjects’ facial fluctuating asymmetry was determined by geometric morphometrics.

Results  The results revealed that in both men and women, higher self-perceived attractiveness and fewer minor ailments predicted lower scores of Somatization, Obsessive–Compulsive, Interpersonal Sensitivity, Depression, Anxiety, Phobic Anxiety, Paranoid Ideation, Psychoticism, and a General Psychopathology Index. Higher facial fluctuating asymmetry was associated with higher Interpersonal Sensitivity, but did not contribute to its prediction when controlling for the other studied variables.

Conclusions  The observed strong associations between self-perceived attractiveness, minor ailments, and psychopathology indicate common developmental pathways between physiological and psychological symptomatology which may reflect broader life history (co)variation between genetics, developmental environment, and psychophysiological functioning.

Discussion

This research assessed whether facial FA measurements, perceptions of attractiveness, and reports of minor ailments are associated with mental health through a lower occurrence of psychopathological symptoms in a mixed sample of young adults. The results indicated that in both men and women, higher self-perceptions of facial attractiveness and fewer minor ailments predicted lower scores of Somatization, Obsessive–Compulsive, Interpersonal Sensitivity, Depression, Anxiety, Phobic Anxiety, Paranoid Ideation, Psychoticism, and the General Psychopathology Index. Higher facial fluctuating asymmetry was associated only with higher Interpersonal Sensitivity, but did not contribute to its prediction when controlling for the other studied variables.

The observed strong associations between self-perceived attractiveness, reports of minor ailments, and mental health outcomes in both sexes support and extend previous results on the relationship between phenotypic indicators of attractiveness and developmental psychopathologies (e.g., Ehlinger & Bashill, 2016). According to previous literature, perceived high attractiveness is associated with higher physical fitness (Hönekopp et al., 2004), greater reproductive success (Singh, 1993), better social competence (Eagly et al., 1991), better immune function (Luoto et al., 2021), and good self-esteem (Bale & Archer, 2013; but see Mares et al., 2010). This would explain why, in the present study, higher self-perceptions of attractiveness contributed to the expression of lower psychopathological symptoms.

Although the relationships between minor ailments and mental health have not been tested in these previous studies, our results suggest that both self-perceived attractiveness (as a result of genetics, developmental environment, and previous sociobiological interactions) and minor ailments (as indicators of general health) could be cues of mental health in men and women. Thus, the present findings build on previous literature by going beyond the use of questionnaires to evaluate mental health by integrating phenotypic traits and markers of general health. This approach allows establishing a more holistic understanding of the variables that play a role in the development of psychopathological symptoms that might also be involved in the development of mental disorders. Moreover, even though our study did not aim to test the association between LH strategies and mental health outcomes, our results suggest that LH dynamics might be associated with the expression of physically attractive traits and mental health outcomes through environmental disturbances that affect resource allocation during the development of an individual (cf. Kahl et al., 2020; Kavanagh & Kahl, 2018; Luoto et al., 2021). Further research may benefit from integrating phenotypic indicators of attractiveness and markers of general and mental health with LH theory to test how these variables are predicted by LH strategies and/or experienced harshness/unpredictability.

The impact of innate attractiveness on social interactions during development is evident very early in life, even before other traits like musculature, sports ability, or dominant behavior (Bobadilla et al., 2013). For example, Langlois et al. (1995) observed that mothers of attractive infants were more prone to be emotional and playful with them. In contrast, the opposite effect was observed with less attractive infants. Likewise, Cash (1980) reported that observers and parents gave better ratings on behavior, health, and intelligence to attractive infants than less attractive ones. Other studies have found that less attractive children had higher probabilities of being physically abused and treated less favorably by teachers than more attractive ones in preschool years (Sweeting & West, 2001). Thus, lower self-perceived attractiveness could be associated with stressful social situations in the early stages of life, a risk factor that contributes to the development of psychopathological symptoms in later years (e.g., Doom & Cicchetti, 2018; Eisenbarth et al., 2019). However, based on these studies, it is not possible to disentangle correlation from causation, and other latent variables—some of which may be endogenous rather than exogenous—may be driving the association between attractiveness and the nature of social experiences.

Stressful life events and limited resource availability contribute to impaired health and immune function in children and adolescents (Dunkel et al., 2020; Kim et al., 2020; Schmeer et al., 2019; Wickrama et al., 2005; Yiğit et al., 2018). For example, children born in socioeconomically disadvantaged families had higher probabilities to have developmental impairments due to the inability to provide proper nutrition, vaccination, and adequate access to health care (Krams et al., 2019; Lauringson et al., 2020; Rubika et al., 2020). Likewise, children from unstable family environments are more likely to develop fast LH strategies which can contribute to the development of higher psychopathological symptoms (Hurst & Kavanagh, 2017; Kahl et al., 2020). Chronically stressful life experiences and/or lack of resources may exert deleterious effects on biological functioning (Luoto et al., 2021) that could be translated into a higher number of minor ailments and fast LH strategies that, based on our results, would contribute to the prediction of psychopathological symptoms (Hurst & Kavanagh, 2017; Schmeer et al., 2019; Wickrama et al., 2005). Thus, this previous literature supports the view of self-perceived attractiveness and minor ailments as outcomes of mental health, rather than the other way around. However, it is also possible that perceptions of attractiveness, minor ailments, and mental health can be mutually influenced and/or be connected by a latent variable, such as genetic heritability and covariation between those traits. As another possibility, previous studies have reported that some mental disorders such as depression and bipolar disorder are associated with low-grade neuroinflammation (Rantala et al., 2018, 2021). This low-grade neuroinflammation and the increase of proinflammatory cytokines may reduce the bioavailability of neurotransmitters such as serotonin, norepinephrine, and dopamine (Miller, 2009), leading to low mood and sickness behavior that may promote a warped self-image and, probably, lower self-perceptions of attractiveness (Rantala et al., 2019).

On the other hand, even though we found that facial FA—a physical trait related to apparent health and developmental stability (Stephen & Luoto, 2021)—was positively correlated with Interpersonal Sensitivity scores, the effect size was low (r = 0.105) as most of the previous studies have reported (e.g., Borráz-León & Cerda-Molina, 2015; Pound et al., 2007). Facial FA was not correlated with any of the other psychopathological dimensions. Thus, it is possible that facial FA is more related to indicating an optimal developmental environment rather than mental health both in humans and non-human animals (Borráz-León et al., 2017b; De Anna et al., 2013; Luoto et al., 2021). However, it is noteworthy that the present research partially replicates and extends previous results (e.g., Shackelford & Larsen, 1997; Thornhill & Møller, 1997) on the relationship between facial FA and psychophysiological stress, with the advantage of using statistical analyses beyond a bivariate correlational approach, a more reliable technique for calculating facial FA (Fink et al., 2005), and a higher sample size (i.e., three times higher) than in previous research (e.g., Shackelford & Larsen, 1997).

It is also possible that insults from poor developmental environments may contribute to a dysregulation of physiological systems (e.g., the hypothalamic–pituitary–adrenal axis) affecting the development of symmetrical traits and contributing to altered cortisol responses and higher stress perceptions (Borráz-León et al., 2017b), which, in turn, would affect mate value, attractiveness, and health indicators (Borráz-León et al., 2017a; Rantala et al., 2019). In contrast, self-perceived attractiveness could be more directly related to mental health. This hypothesis is in line with the multiple fitness model (Cunningham et al., 1995) which proposes that perceived physical attractiveness results from the evaluation of multiple features rather than a single one, signaling different aspects of mate value (Little et al., 2006; Luoto, 2019; Miller & Todd, 1998; Stephen & Luoto, 2021). Thus, our results suggest that self-perceived attractiveness and number of previous ailments may not only signal general health, thereby affecting sexual selection processes, but that they may also covary with mental health outcomes.

Limitations

It is possible that our findings arose from response bias covariance since SCL-90-R is a self-rating instrument and its accuracy relies on correct interpretation of questions, which is susceptible to denial, minimization, and bias mechanisms (Eisen et al. 1999). Nevertheless, a moderate-to-high reliability and internal consistency of the SCL-90-R have been reported in the literature (e.g., Otte et al., 2017), including in this study. The αs of the psychopathological symptoms range from 0.76 to 0.81, which reduced the probability of bias in the responses.

Another possible limitation of this study is that we did not measure self-esteem in our sample. Since self-esteem tends to be associated with positive social outcomes (e.g., Borráz-León et al., 2018, 2019b; Harris & Orth, 2020), and since higher self-perceived attractiveness predicted lower psychopathological symptoms in our sample, it is possible that mechanisms such as low self-esteem, warped self-image, and adverse childhood experiences, which could be driven by psychopathology, could lead to lower self-perceived attractiveness and impaired mental health (cf. Rantala et al., 2019).

As this study was conducted only on university students, further studies with more heterogeneous samples are needed to increase the generalizability of the results, as well as to investigate the role of self-esteem as a mediator in the associations between self-perceived attractiveness and psychopathological symptoms. Based on these data, we are unable to verify the direction of causality between self-perceived attractiveness, minor ailments, and psychopathological symptoms, or whether latent variables underlie these associations.

Recent work on bullying perpetration includes the hypothesis that bullying carries an evolutionary advantage for perpetrators in terms of health & reproductive success; paper confirms the last, but health is worse

Benefits of Bullying? A Test of the Evolutionary Hypothesis in Three Cohorts. Tina Kretschmer, Chaïm la Roi, Rozemarijn van der Ploeg, René Veenstra. Journal of Research on Adolescence, August 27 2021. https://doi.org/10.1111/jora.12675

Abstract: Recent work on bullying perpetration includes the hypothesis that bullying carries an evolutionary advantage for perpetrators in terms of health and reproductive success. We tested this hypothesis in the National Child Development Study (n = 4998 male, n = 4831 female), British Cohort Study 1970 (n = 4261 male, n = 4432 female), and TRacking Adolescents’ Individual Lives Survey (n = 486 male, n = 521 female), where bullying was assessed in adolescence (NCDS, BCS70: age 16, TRAILS: age 14) and outcomes in adulthood. Partial support for the evolutionary hypothesis was found as bullies had more children in NCDS and engaged in sexual intercourse earlier in TRAILS. In contrast, bullies reported worse health in NCDS and BCS70.

DISCUSSION

Bullying has played an important role in the developmental literature and in educational policy in the last few years. This surge in attention was fueled by a plethora of studies on maladjustment of victims. Negative outcomes have also been ascribed to perpetrators, but the scientific evidence here is thinner. In fact, some longitudinal studies leave doubt as to whether bullying others actually carries risk for maladjustment (Copeland et al., 2013; Wolke et al., 2013). Bullying research inspired by evolutionary theory has even suggested that bullies might reap benefits in the form of better health, access to partners, and reproductive opportunities. Here, we tested whether bullying was indeed linked to these outcomes in three cohorts.

Across the older cohorts (NCDS and BCS70), bullies showed worse health outcomes in middle adulthood. At first sight, this finding is not supportive of the hypothesis that bullying perpetrators are exposed to less stress given their rank in the social pecking order and thus should theoretically reap the benefits in form of better health (Volk et al., 2012). It appears that decreased stress among bullies is linked to better health in the short term—as supported by a study into differences by bullying status in increases in systemic inflammation levels from adolescence to early adulthood (Copeland et al., 2014)—but that this beneficial effect does not last for decades. In fact, bullying perpetrators engage in health-adverse behaviors (Ttofi et al., 2016) and experience more stress—though not necessarily worse health—as adults (Matthews et al., 2017). It is possible that negative health outcomes emerge later in life, which might explain why we did not observe this association in TRAILS. For instance, bullying perpetrators might continue to aggress against work colleagues and partners (Farrell & Vaillancourt, 2019; Matthiesen & Einarsen, 2007), thus jeopardize employment, friendships, and relationships and end up unhappy and unhealthy as adults. Bullying perpetration has also been associated with substance use later on (Vrijen et al., 2021), which has negative effects on physical health as well. Not detecting this association in TRAILS might mean that bullying perpetration in this cohort is still ongoing and health benefits resulting from lower social stress are continued to be reaped for the time being.

Notably, whereas health was worse among bullying perpetrators in NCDS and BCS70, NCDS participants had more offspring, the clearest indicator of evolutionary benefit. An association with a greater number of offspring was also observed among BCS70 when bullies and nonbullies were compared prior to matching. Bullies in the TRAILS sample engaged in sexual behavior earlier than nonbullies. Whereas early sex tends to be seen as risk behavior in developmental terms, it widens the span of years for reproduction and is thus considered beneficial from an evolutionary perspective. In this regard, the TRAILS results match those for NCDS and the unadjusted ones for BCS70.

It is worth keeping in mind that it might not be bullying in and of itself that conveys a reproductive advantage but that unexamined third variables explain both. Life-history theory, for instance, would suggest that traits and behaviors that represent fast life strategy and allocation of resources to reproduction increase someone’s likelihood to bully others as well as lower age at first sex and more offspring. A life-history perspective would also explain long-term links between bullying and the other outcomes examined in this study as individuals following a fast life-history strategy allocate resources to reproduction rather than somatic fitness. Bullies might forego good health in order to reap reproductive benefits, which is ultimately adaptive because transmission of genes is more important in an evolutionary sense than being healthy in old age. As such, negative health outcomes for bullying perpetrators would not necessarily mean that bullying is not at all adaptive because reproducing early and manifold is more important than preserving good health. A reproductive-versus-somatic trade-off would explain why bullying perpetrators enjoy greater reproductive success but suffer from worse health later on. Unfortunately, NCDS is the only cohort in our study where reproductive activity can be assumed to be more or less concluded, certainly among the female participants. If indeed the number of offspring is also higher among bullying perpetrators in BCS70 once this cohort has completed reproduction, that is, if NCDS results are replicated in another cohort, it would be interesting to study whether bullies who had more offspring are worse off in terms of health; thus whether short-term benefits in favor of long-term costs can be observed.

Perspectives on bullying that are not informed by evolutionary theory would suggest that bullying perpetration and earlier sex—for which we found a link in TRAILS—are both expressions of externalizing maladjustment, a view that in our data is supported by the higher levels of child psychopathology among bullies than nonbullies. Age at first sex and the bullying perpetration assessment will have been temporally closer to one another than bullying and some of the other outcomes in TRAILS, which underlines the possibility that both are concurrent expressions of an underlying construct such as externalizing behavior. It will be important to follow up on the BCS70 and TRAILS participants at an age similar to that of NCDS participants now to see whether divergent results across the samples used here indicate unstable, nonreplicable associations or have substantive meaning.

One might doubt whether are earlier age at first sex and number of partners and children are meaningful indicators of success and advantage in contemporary Western societies where slow life strategies dominate (Twenge & Park, 2019). At least within the developmental literature on adolescence and young adulthood, having many partners is considered an expression of maladjustment and risky sexual behavior and promiscuity in adulthood is often seen as a symptom of psychopathology. Contextual conditions might also be implicated in this link, such as norms in the peer group that favor both bullying and risky sexual behavior. Though this perspective suggests that it is not meaningful to study number of partners and children as solely positive outcomes, they still indicate reproductive success in an evolutionary sense. In other words, what is adaptive in an ultimate sense (maximized reproduction) might not be desirable in a proximate sense, given the stigma attached to families with greater number of offspring and societal norms surrounding numbers of sexual partners.

Limitations

Perhaps the most substantial limitation of this study is the bullying perpetration measurement. Though it is remarkable that researchers assessed bullying when child psychology had hardly picked up on the topic and its negative developmental outcomes, single-item assessments are clearly not optimal. Parents and teachers have a limited view on who engages in bullying (Ahn, Rodkin, & Gest, 2013) – and will have had so even more at a time when bullying did not receive the attention from educational policymakers and media as it does today. As a consequence, measures of bullying in NCDS and BCS70 might lack validity and will also not have included nonovert forms of bullying. Moreover, bullying by popular, high-status adolescents might not have been viewed by adults as the destructive behavior it is for victims and noninvolved peers and parents might generally be unaware of the behavior of their children at school unless informed and might have responded with other target of bullying in mind. Of note, however, the proportion of bullying perpetrators in NCDS and BCS70 is similar to that found in studies that used multi-item self-report measures (Espelage, Van Ryzin, & Holt, 2018). Moreover, whereas more recent studies provide participants with a definition of bullying that ideally encompasses its different dimensions (Kaufman, Huitsing, & Veenstra, 2020) such detail was not provided to the three samples on which our analyses are based. It might thus be that the outcomes only hold for perpetrators who engage in visible, direct forms of bullying behavior, such as physical and verbal bullying. Next to using bullying information from different reporters in TRAILS versus NCDS and BCS70, assessments were also done at a slightly younger age in TRAILS. Bullying is related to status more so in adolescence than in childhood which might have meant that associations with outcomes would be more pronounced in the cohorts where the assessment was conducted in mid- rather than early adolescence.

It could also be argued that what we conceptualized as bullying is actually general aggression, or understood by parents and teachers in NCDS and BCS70 as tapping into aggression more generally. Both bullying and aggression are used strategically to obtain social dominance to control resources (Hawley, 1999) and to increase reproductive success (Lindenfors & Tullberg, 2011; Vaillancourt, 2005). As such, the evolutionary propositions would to some extent be similar but lower health in adulthood would be expected for aggressive behavior and not necessarily, from an evolutionary perspective, for bullying perpetration, even though bad health might be acceptable in light of successful reproduction. We corrected for childhood psychopathology to account for this at least partly.

Next to the use of a single item to measure bullying, the present study should be interpreted in light of other methodological challenges: First, attrition was selective and, across samples, bullying perpetration predicted missing data on outcomes. Whereas multiple imputation provides a more advanced way to deal with missing data than case deletion or mean imputation, it would be important to see whether the results hold on more complete data.

Second, we dichotomized ordinal bullying perpetration scores for NCDS and BCS and proportion scores for TRAILS. This was done to harmonize bullying perpetration measures as much as possible across samples, avoid skewed distributions, and to enable the matching procedure but also meant a loss of information. We chose cutoff scores for dichotomization in a way that would return reasonably comparable group sizes and applied this strategy also to victimization and popularity. It is not optimal that these cutoffs are therefore based on methodological rather than substantive considerations. One might ask whether results would have looked different if only those individuals with more extreme scores would have been included in the bully matching group. It is feasible that associations would be more pronounced (even worse health outcomes, more partners, more children) but this would have led to a vastly smaller group than its counterpart (nonbully), which would have increased the risk for model instability.

Third, the matching procedure allowed for a range of relatively subjective decisions, for instance between fixed and variable ratio matching and with respect to pruning (e.g., more pruning leads to better matching but to smaller samples). As developmental researchers increasingly use advanced methods, close collaboration between developers of such analyses packages and applied researchers is needed to ensure user friendliness and correct application.

Fourth, three samples from different periods were included which means that differences in effects might be explained by cohort effects. NCDS represents the first generation to grow up with the birth control pill being widely available but maybe not yet as accepted across all groups in the UK population. Tentatively, this might mean that number of children was less controlled by women in this cohort than in BCS70 and TRAILS. Similarly, covariates such as SES might have exerted a different influence on outcomes on those from the earlier compared to later-assessed cohorts and childhood psychopathology might have carried a greater stigma in the older cohorts.

Fifth, differences in measurement across the cohorts, and especially for TRAILS in comparison to NCDS and BCS70, might explain discrepancies in results. An example for this is the health assessment, which was kept broad in NCDS and BCS70 but referred explicitly to physical health in TRAILS. Another example concerns the number of partners, which reflects number of partners with whom the participant has cohabited for at least 1 month in NCDS and BCS70 whereas this variable refers to number of sexual partners in TRAILS. The former represents an imperfect assessment from an evolutionary standpoint, where number of sexual partners would have been the preferred measure. The value of the British cohorts in terms of length and inclusion of a bullying assessment long before the topic entered the mind of researchers, however, outweigh this limitation in our view.

Sixth, our central aim was to test Volk’s hypothesis of bullying as evolutionary adaptation (Volk et al., 2012) and we selected three cohorts where outcomes were assessed at different ages. Whereas we examined moderation by popularity and victimization – assessed at the same time as bullying perpetration, we did not explore potential mechanisms that might carry the effects of adolescent bullying into (late) adulthood. Our reasoning implicitly suggested that bullies retain a high status, but this remains to be tested. Another possibility might be that bullies who are successful in dating in adolescence and early adulthood build up and retain self-confidence when it comes to establishing sexual relationships and are able to build larger social networks which again adds opportunities to meet a potential (sexual) partner. Adolescents who frequently change their dating partners might settle down later and thus accumulate a greater number of partners even into adulthood. At present, the lack of longitudinal studies on stability of bullying status hinders any rigorous testing of such mechanisms. In a similar vein, it is difficult to derive immediate practical implications from the findings presented here. Naturally, bullying prevention needs to remain on the agenda even if only for victims, who carry the greatest plight. Reducing bullying in schools, however, will hardly eradicate evolutionary advantages for high-status individuals and high status among adolescents is linked to aggressive behavior. From a life-history strategy perspective, one might want to attempt to reduce antecedents for fast life strategies, such as growing up in harsh and unpredictable environments (Belsky, Schlomer, & Ellis, 2012), but it is somewhat doubtful that these are tasks for antibullying pre- and intervention programs. In that sense, the results of this study should be seen as furthering our understanding of long-term correlates of bullying but cannot immediately be translated into policy or practical implications.

Finally, we preregistered analyses but realized that not all premade analytic decisions were optimally suited. For instance, we intended to follow previous conceptualizations of bullying perpetration in TRAILS (Veenstra et al., 2005) but discovered that this would lead to too few bullying perpetrator cases to meaningfully use in matching. Moreover, we had not anticipated that so few children had been born to TRAILS participants yet, which made analyses with number of children as a count variable unreliable. These deviations from the preregistration highlight that some decisions are easier when the data are known.

Mouse movements linked to more deliberate responding (less unnecessary clicks, more fixations) are associated to higher Conscientiousness, Agreeableness, and Openness, and lower Neuroticism

Meidenbauer, Kimberly L., Tianyue Niu, Kyoung Whan Choe, Andrew Stier, and Marc Berman. 2021. “Mouse Movements Reflect Personality Traits and Task Attentiveness in Online Experiments.” PsyArXiv. August 30. doi:10.31234/osf.io/eqhdw

Abstract: In this rapidly digitizing world, it is becoming ever more important to understand people’s online behaviors in both scientific and consumer research settings. A cost-effective way to gain a deeper understanding of these behaviors is to examine mouse movement patterns. This research explores the feasibility of inferring personality traits from these mouse movement features (i.e., pauses, fixations, cursor speed, clicks) on a simple image choice task. We compare the results of standard univariate (OLS regression, bivariate correlations) and three forms of multivariate partial least squares (PLS) analyses. This work also examines whether mouse movements can predict task attentiveness, and how these might be related to personality traits. Results of the PLS analyses showed significant associations between a linear combination of personality traits (high Conscientiousness, Agreeableness, and Openness, and low Neuroticism) and several mouse movements associated with slower, more deliberate responding (less unnecessary clicks, more fixations). Additionally, several click-related mouse features were associated with attentiveness to the task. Importantly, as the image choice task itself is not intended to assess personality in any way, our results validate the feasibility of using mouse movements to infer internal traits across experimental contexts, particularly when examined using multivariate analyses and a multiverse approach.

Combined, our results provide comprehensive support for the argument that intrasexual selection has uniquely shaped Homo sapiens upper limb length to enhance fighting performance in real-world combat

Caton, Neil R., and David M. G. Lewis. 2021. “Armed Forces: Intrasexual Selection for Upper Limb Length in Homo Sapiens.” PsyArXiv. August 31. doi:10.31234/osf.io/fw6s9

Abstract: Numerous taxa have evolved physiological appendage-based weaponry to increase damage output in violent fights, but no research has empirically shown that Homo sapiens upper appendages have uniquely evolved to increase resource-provisioning potential in real-world combat. In Study 1, we used actual fight outcome data (N = 715 fighters) to examine multiple competing hypotheses—the striker, defender, grappler, and knockout hypotheses—for the evolution of Homo sapiens upper limb length, controlling for approximately a dozen confounding variables (e.g., biacromial width, lower limb length, age, weight, height). There was exclusive support for the knockout hypothesis: upper limb length increases fighting success through knockout power. There was also evidence for a real-world association between biacromial width and knockout power. Because sexual dimorphism often emerges from selection on morphological structures that improve male’s fighting success, we consequently expected sexual dimorphism in upper limb length. Studies 2a-2d provided powerful evidence for this new universal sexual dimorphism in upper limb length. Even after controlling for weight, height, and lower limb length, males exhibited longer upper limbs than females across the globe: from mixed-martial-artists (Study 2a) and Croatian adolescents (but not pre-pubertal children; Study 2b) to older Singaporean adults (Study 2c) and over 6,000 United States Army personnel (Study 2d) born across seven major world regions (Africa, Europe, Asia, Oceania, and North, Central, and South America). Combined, our results provide comprehensive support for the argument that intrasexual selection has uniquely shaped Homo sapiens upper limb length to enhance fighting performance in real-world combat.

Loving you from afar: Attraction to others (“crushes”) among adults in exclusive relationships, communication, perceived outcomes, and expectations of future intimate involvement

Loving you from afar: Attraction to others (“crushes”) among adults in exclusive relationships, communication, perceived outcomes, and expectations of future intimate involvement. Lucia F. O’Sullivan, Charlene F. Belu, Justin R. Garcia. Journal of Social and Personal Relationships, August 24, 2021. https://doi.org/10.1177/02654075211038612

Abstract: Crushes are uncommunicated, often unilateral, attractions to an individual, generally viewed as a state of unfulfilled longing. They are typically attributed to young people, but recent research suggests that these experiences might be common among adults as well, including among those in committed relationships. Combining findings from three studies across four datasets, this mixed-methods research explores crushes experienced by individuals in committed intimate relationships. Study 1 explored types of crushes, preferences and nature of exchanges among adults in committed relationships and compares their reports to a sample of single individuals. Study 2 examined perceived outcomes of crushes as a way to assess needs or goals served by crushes. Study 3 investigated expectations about whether and how the crush relationship might evolve into a more intimate relationship. A total of 3,585 participants (22–45 years, 53.1% women) completed anonymous online surveys addressing crush experiences and related dynamics. Those in committed relationships typically did not intend to communicate their attraction to the target, unlike single individuals. Associated outcomes were primarily positive, including excitement, increased esteem, and fantasy/escape. The vast majority reported no expectations that these crushes would evolve into more intimate relationships, replacing their current relationship. This work adds to our understanding of attraction outside of traditional human courtship processes, with implications for the study of intimate relationship development and maintenance.

Keywords: Attraction, committed, crush, intimate, romantic, sexual, single

General discussion

This series of exploratory studies on crushes was designed to provide some early insights into the nature of exchanges with attractive others for those in committed relationships, outcomes associated with having these attractions, and expectations of future involvement with the target of one’s attraction. Moving us beyond a focus on attraction to others as an indicator of poor relationship quality or a precursor to infidelity, the current series of studies established that these attractions most often seemed instrumental in gaining fairly positive psychosocial outcomes, such as diversion, fun, or excitement.

Overall, few individuals in ostensibly exclusive relationships reported plans to advance the crush relationship further. By comparison to singles, those in relationships were more inclined to keep their attraction covert and were more satisfied to simply flirt with someone for whom they experienced attraction rather than communicate their interest directly.

These findings raise the obvious question of why humans might exhibit and entertain feelings of crushes in the first place, if they are expected to go unfulfilled—that is, unlike in other models of attraction, an individual does not seek out the object of the crush. On the surface, this would seem to be a poor use of an individual’s time and effort, resources meant to be adaptively leveraged in mating contexts. It is possible that these crush attractions are simply inevitable, that we cannot turn off the psychological system that helps us orient toward potential partners when we enter an established relationship. The Instrumentality Principle would indicate that these behaviors meet a motivational priority, moving an individual toward a valuable goal. However, these attractions might reassure individuals that there are other options should the primary relationship falter (i.e., mate switching; Buss et al., 2017). Similarly, many young adults report maintaining “back burner” relationships, that is, a connection with someone who they might someday connect with romantically or sexually (Dibble & Drouin, 2014; Dibble et al., 2015). Crushes might comprise a means of gauging or testing one’s commitment and interest in preserving a primary relationship.

We did not assess relationship quality of one’s primary relationship. Although participants’ self-reports suggest that crushes are relatively benign experiences, further research is needed to examine under which conditions a crush might undermine relationship quality. Intensity of one’s attraction, especially if it increases over time, mutuality of the attraction and the response of the crush target should they want to pursue a relationship are likely important moderators, as is quality of the primary relationship in terms of satisfaction and commitment. Primary relationships of lower quality are likely more vulnerable to one or both partners becoming distracted by another. We also should examine more closely the impact of the secrecy involved with crushes and indeed how much is concealed from a primary partner. Secret attraction when linked with fear of its being exposed might amplify attraction through misattribution of arousal (“excitement transfer” Marin et al., 2017; Meston & Frohlich, 2003) or frustration attraction (Fisher, 2005).

Study limitations

There are other limitations that need to be acknowledged. Our use of cross-sectional data rather than longitudinal data renders any speculation about links to relationship outcomes unwarranted. A longer trajectory, ideally using prospective methods, would allow researchers to better capture outcomes associated with attractions to others. This is a limitation of the study designs, and short of tracking individuals from the onset of their relationship, one that cannot be easily overcome. In addition, it is important to bear in mind that self-reports about sensitive topics, such as attractions to others, are often subject to issues of presentation biases. However, in every case, we ensured that participants were fully informed of the anonymous nature of their reports, which we believe offset some of the biases these concerns might introduce.

Although we were able to study gender differences to some extent, we were only able to explore differences in terms of sexual identity in the first of our three studies. Those who identified as sexual minorities (gay, lesbian, or bisexual) reported more types of crushes than did those who identified as heterosexual. This finding might reflect pressure among sexual minority individuals to keep same-sex attractions hidden. Exploring these attractions in larger and/or more diverse populations will help us determine how a mechanism that evolved to guide individuals toward a viable romantic and sexual partner with whom we intend to bond and mate (Berscheid, & Reis, 1998; Fisher, 1998; Sprecher & Hatfield, 1985) operates in contexts in which an intimate relationship is ostensibly not the goal.

Older faces are rated as less attractive than younger faces; older perceivers are less influenced by the age of the viewed face; men distinguish more clearly between faces when judging attractiveness, especially in female faces

The effect of aging on facial attractiveness: An empirical and computational investigation. Dexian He et al. Acta Psychologica, Volume 219, September 2021, 103385. https://doi.org/10.1016/j.actpsy.2021.103385

Highlights

• Older faces are rated as less attractive than younger faces and treated like a category when making aesthetic judgments.

• Older perceivers are less influenced by the age of the viewed face than younger and middle-aged perceivers.

• Men, more than women, distinguish more clearly between faces when judging attractiveness, especially in female faces.

• Aging has less of an effect on judgments of elegance than beauty and gorgeousness.

Abstract: How does aging affect facial attractiveness? We tested the hypothesis that people find older faces less attractive than younger faces, and furthermore, that these aging effects are modulated by the age and sex of the perceiver and by the specific kind of attractiveness judgment being made. Using empirical and computational network science methods, we confirmed that with increasing age, faces are perceived as less attractive. This effect was less pronounced in judgments made by older than younger and middle-aged perceivers, and more pronounced by men (especially for female faces) than women. Attractive older faces were perceived as elegant more than beautiful or gorgeous. Furthermore, network analyses revealed that older faces were more similar in attractiveness and were segregated from younger faces. These results indicate that perceivers tend to process older faces categorically when making attractiveness judgments. Attractiveness is not a monolithic construct. It varies by age, sex, and the dimensions of attractiveness being judged.

Keywords: Face perceptionAgeSexAttractivenessNetwork science

4. Discussion

The present study used empirical and computational network science methods to investigate the effect of aging on attractiveness and to examine how this effect is modulated by the perceiver's age, sex, and dimensions used to make attractiveness judgments. Using highly controlled stimuli, and replicating earlier observations, we found that older faces were perceived as less beautiful, elegant, and gorgeous, and they were liked less. Further, young people rated young faces as more attractive than did older perceivers. Older female faces received lower ratings from male perceivers than female perceivers, suggesting that the age of faces influenced men's ratings for attractiveness more robustly than it does for women making ratings; Finally, beauty, elegance, and gorgeousness ratings were affected differently by age. While the ratings for all these attractiveness descriptors diminished with age, elegance was affected least.

We also observed a relative categorical perception of older faces in that they were viewed more similarly to each other (i.e., they clustered closer together) than the other two groups of faces in face preference networks, which could make it easier for older faces to be subject to negative stereotyping. Alternatively, it's also possible that negative biases towards older individuals make people less inclined to distinguish them. Consistent with these interpretations, older faces were more segregated from and located further away from younger faces compared to middle-aged faces in the networks, again suggesting older faces were more distinct from younger faces in facial beauty.

Perceivers showed negative biases towards older faces, rating them as less beautiful, gorgeous, elegant, and liked. Face preferences are regarded as adaptations for mate choice since attractive traits signal mate quality (Grammer et al., 2003; Rhodes, 2006). The human brain may have evolved to favor these traits (Chatterjee, Thomas, Smith, & Aguirre, 2009; Rellecke et al., 2011). Thus, an evolutionary mechanism might enhance perceptual sensitivity towards younger faces. Alternatively, younger people may simply have less exposure to and experience with older faces. Faces of one's own age group are better recognized and remembered than faces of another age group (own-age bias, OAB; Bartlett & Leslie, 1986; Ebner et al., 2013). Either way, older faces were judged as less distinct from each other and treated more categorically when making attractiveness judgments.

Despite commonalities, the structural properties of the networks varied across perceiver age, sex, and dimension of attractiveness. Faces in the older perceivers face preference network were more segregated than those of younger perceivers. As perceiver age increased, older faces were seen as more distinct in attractiveness. These dynamic changes may reflect that our face preferences are updated by experiences and exposures to faces across the lifespan.

Considerable research has demonstrated that environmental factors, including cumulative environmental exposure and different environments, contribute to age differences in human cognition (Siew et al., 2019; Wulff, De Deyne, Aeschbach, & Mata, 2021; Wulff, De Deyne, Jones, & Mata, 2019). Individuals continue to learn as they get older. Older people are assumed to have acquired more knowledge (e.g., broader vocabulary) than younger people, which subsequently leads to the concepts becoming more distant and further apart from each other in their mental representation (Cosgrove et al., 2021; Wulff, De Deyne, Aeschbach, & Mata, 2021). This may account for the pattern observed in the older adults' semantic network and the similar segregated effect in face preference networks. Research on face preferences also emphasizes the substantial role of experience/environmental factors in shaping our notions of attractiveness (Germine et al., 2015). The cumulative exposure to faces has important implications for individual face preferences. Older people have been generally exposed to more faces and have more diverse experiences compared to younger and middle-aged perceivers. Regarding different environments, people interact more with peers in daily life. These cohort effects may contribute to older viewers being less influenced by the age of the viewed face and more discriminating with older faces in attractiveness. Taken together, we propose that differences in face experience may account for the age-related changes in perception of attractiveness that we report. Older people's experiences and preferences cover a greater span of time.

Men, more than women, segregated faces into clusters by age and sex. The homophily analysis also showed that men more than women were likely to associate same sex faces together. Finally, men viewed faces from different ages and sexes as more organized and more segregated, suggesting they make more distinctions between faces when judging facial beauty. These observations confirm the hypothesis that men are more sensitive to features of physical attractiveness than women, they are more likely to treat face attractiveness categorically, and their sensitivity is further pronounced when judging women's faces.

Sex-specific mating strategies might be reflected in these perceptions of facial attractiveness. Men tend to prioritize women's physical attractiveness, healthiness, and youth, which are theorized to ultimately increase reproductive success and off-spring quality. In contrast, women are thought to value men's status and resources more than attractiveness (Li & Kenrick, 2006; Rhodes, 2006). Empirical data also corroborate that these mate preferences translate into actual mating behavior (Conroy-Beam & Buss, 2018; see also Buss & Schmitt, 2018). Such sex differences in preferences for physical appearance are likely important drivers of differences in perceptions of attractiveness between men and women. However, these strategies are confined to theorizing about heterosexual mating contexts. We do not know if these results would generalize to non-heterosexual individuals.

Finally, there was a stronger association of the dimension of elegance with older than younger and middle-aged faces, and with female than male faces. Elegance, as a descriptor of attractiveness, seems to alert people to finer distinctions in attractiveness for older than younger faces. The overall decrease in attractiveness judgments by age is muted for elegance compared to beauty or gorgeousness is consistent with the view that the notion of elegance goes beyond physical attractiveness, and signals non-physical properties (Menninghaus et al., 2019). We speculate that elegance incorporates cultural norms of attractiveness that are not tethered to physical features as tightly as for beauty and gorgeousness.

We extend previous findings for aging effects to different aspects of attractiveness and revealed differences in the processes people use when judging attractiveness of older faces. However, our study has a few limitations. Different effect sizes were observed for the three network measures in face preferences networks. This probably indicates that one data source is better than the other for these psychometric networks. Future studies are needed to replicate and strengthen our findings. In addition, age-related differences may result from generational or/and developmental differences. We suggest that face preference is influenced by face experiences across the lifespan. But it is hard to quantitatively measure individual difference in face experiences. Whether our findings are the effect of specific generational cohorts or actual aging and accumulation of experience is difficult to determine. Our study was also conducted in the US. American culture may disproportionately value youth. Perhaps these aging effects would be mitigated in cultures with different attitudes towards the elderly.

Coping with global uncertainty: Perceptions of COVID-19 psychological distress, relationship quality, and dyadic coping for romantic partners across 27 countries

Coping with global uncertainty: Perceptions of COVID-19 psychological distress, relationship quality, and dyadic coping for romantic partners across 27 countries. Ashley K. Randall et al. Journal of Social and Personal Relationships, August 26, 2021. https://doi.org/10.1177/02654075211034236

Abstract: Following the global outbreak of COVID-19 in March 2020, individuals report psychological distress associated with the “new normal”—social distancing, financial hardships, and increased responsibilities while working from home. Given the interpersonal nature of stress and coping responses between romantic partners, based on the systemic transactional model this study posits that perceived partner dyadic coping may be an important moderator between experiences of COVID-19 psychological distress and relationship quality. To examine these associations, self-report data from 14,020 people across 27 countries were collected during the early phases of the COVID-19 pandemic (March–July, 2020). It was hypothesized that higher symptoms of psychological distress would be reported post-COVID-19 compared to pre-COVID-19 restrictions (Hypothesis 1), reports of post-COVID-19 psychological distress would be negatively associated with relationship quality (Hypothesis 2), and perceived partner DC would moderate these associations (Hypothesis 3). While hypotheses were generally supported, results also showed interesting between-country variability. Limitations and future directions are presented.

Keywords: COVID-19, distress, dyadic coping, multination, relationship quality

Paranoia and negative image about the self and others

Paranoia and negative schema about the self and others: A systematic review and meta-analysis. Charlotte Humphrey et al. Clinical Psychology Review, August 30 2021, 102081. https://doi.org/10.1016/j.cpr.2021.102081

Highlights

• There is a medium to large association between negative self-schema and paranoia.

• There is a medium to large association between negative other schema and paranoia.

• Depression may account for associations between negative self-schema and paranoia.

• Negative schema may mediate relationships between childhood adversity and paranoia.

• Further longitudinal studies are needed to determine the direction of effects.

Abstract: Negative self and negative other schema have been implicated in the development of paranoia. The current study provides a meta-analysis, narrative review and quality appraisal of quantitative studies investigating the relationship between negative self and negative other schema and paranoia across the paranoia continuum. A systematic search identified 43 eligible studies; 25 were included in the meta-analysis. Meta-analytic findings demonstrated a medium to large relationship between paranoia and negative self-schema (r = 0.46, 95% CI 0.39 to 0.53) and negative other schema (r = 0.48, 95% CI 0.38 to 0.56). The magnitude of associations was similar across people with and without psychosis. Findings demonstrated that associations between negative self-schema and paranoia were not always statistically significant when controlling for confounding variables, particularly depression. The association between negative other schema and paranoia tended to remain significant when controlling for confounding variables. Findings also demonstrated that negative schema may mediate relationships between adverse experiences in childhood and paranoia. Overall, findings support theoretical proposals that both negative self and negative other schema are associated with paranoia. Longitudinal studies are required to confirm the direction of effects. Findings provide support for incorporating and targeting negative self and negative other schema in psychological formulations and therapeutic work.

Keywords: SchemaCore beliefsParanoiaPsychosis