Can people detect the trustworthiness of strangers based on their facial appearance? It seems not.

Can people detect the trustworthiness of strangers based on their facial appearance? Bastian Jaeger et al. Evolution and Human Behavior, May 2 2022. https://doi.org/10.1016/j.evolhumbehav.2022.04.004

Abstract: Although cooperation can lead to mutually beneficial outcomes, cooperative actions only pay off for the individual if others can be trusted to cooperate as well. Identifying trustworthy interaction partners is therefore a central challenge in human social life. How do people navigate this challenge? Prior work suggests that people rely on facial appearance to judge the trustworthiness of strangers. However, the question of whether these judgments are actually accurate remains debated. The present research examines accuracy in trustworthiness detection from faces and three moderators proposed by previous research. We investigate whether people show above-chance accuracy (a) when they make trust decisions and when they provide explicit trustworthiness ratings, (b) when judging male and female counterparts, and (c) when rating cropped images (with non-facial features removed) and uncropped images. Two studies showed that incentivized trust decisions (Study 1, n = 131 university students) and incentivized trustworthiness predictions (Study 2, n = 266 university students) were unrelated to the actual trustworthiness of counterparts. Accuracy was not moderated by stimulus type (cropped vs. uncropped faces) or counterparts' gender. Overall, these findings suggest that people are unable to detect the trustworthiness of strangers based on their facial appearance, when this is the only information available to them.

Keywords: TrustTrustworthinessCooperationFace perceptionPredictionAccuracy

4. General discussion

People spontaneously rely on the facial appearance of strangers when deciding whether they can be trusted to cooperate in social interactions (Todorov, Olivola, et al., 2015). But can people actually detect the trustworthiness of strangers based on their facial appearance? Prior studies have yielded mixed results and the question remains the subject of vigorous debate (Bonnefon et al., 2017; Todorov, Funk, & Olivola, 2015). Yet, the empirical evidence on the topic is limited. Many studies were based on the same set of stimuli, which limits the generalizability of findings (Bonnefon et al., 2013; De Neys, Hopfensitz and Bonnefon, 2015, De Neys, Hopfensitz and Bonnefon, 2017). Conversely, studies providing evidence against accuracy relied on statistical techniques that cannot quantify evidence in favor of such a null hypothesis, which complicates the interpretation of results (Efferson & Vogt, 2013; Rule et al., 2013).

We conducted two studies to address these limitations. Confirming results from previous studies (Jaeger, Evans, Stel, & van Beest, 2019), we found that participants relied on the perceived trustworthiness of counterparts when making trust decisions. However, on average, participants failed to entrust money to counterparts that were actually more trustworthy. Bayesian analyses yielded very strong support for the null hypothesis indicating that our participants were not able to accurately detect the trustworthiness of their interaction partners. We also found that participants' earnings were not higher than the expected earnings of a decision strategy that trusts at random. This suggests that knowledge of their counterparts' facial appearance did not give participants a strategic advantage. In fact, participants would have earned more by consistently distrusting all counterparts, as trust did not pay off in the current sample.

Previous studies found evidence in favor of detection accuracy only under specific conditions, and these conditions varied across studies (Bonnefon et al., 2013; Tognetti et al., 2013; Verplaetse et al., 2007). Here, we tested these proposed moderators, but found no evidence for better-than-chance trustworthiness detection (a) for male or female counterparts, (b) when making trust decisions or when providing explicit trustworthiness ratings, and (c) when viewing cropped images (in which all non-facial features were removed) or uncropped images. In sum, our results provide consistent evidence against accuracy in trustworthiness detection from faces across various conditions.

Previous investigations have shown that trustworthiness impressions guide decision-making in many domains, including legal sentencing, personnel selection, and financial decision-making (Olivola et al., 2014). People even rely on trustworthiness impressions from faces when more diagnostic cues are available (Jaeger et al., 2019) and when decisions are highly consequential (Wilson & Rule, 2015). Future studies should explore whether some people are more prone to the biasing influence of first impressions and, importantly how biases could be mitigated (for first attempts, see Chua & Freeman, 2021; Jaeger, Todorov, Evans, & van Beest, 2020; Shen & Ferguson, 2021). An important future task in this line of research will be to delineate how difficult it is to override these biases, particularly when other more reliable information sources are available that may require more cognitive effort to process.

4.1. Limitations and future directions

Several limitations and constraints on the generalizability of the current results should be mentioned. Our results were based on samples of relatively young decision-makers from the University of Zurich. Additional studies are needed to examine the generalizability of our findings with larger and more diverse samples of both targets and raters.

Future studies should also examine the accuracy of trustworthiness impressions using varying types of stimuli. Cropped images, in which all non-facial aspects are removed, ensure that impressions are based on the facial features of counterparts. However, they represent only a relatively specific facet of the kinds of stimuli that people encounter in everyday interpersonal interactions. Accuracy may be better than chance when people have access to additional cues. For instance, previous findings suggest that people may be able to identify cooperative interaction partners with greater-than-chance accuracy after brief interactions (Brosig, 2002; DeSteno et al., 2012; Frank, Gilovich, & Regan, 1993; Reed, Zeglen, & Schmidt, 2012; but see Manson, Gervais, & Kline, 2013; McCullough & Reed, 2016). Ultimately, we believe that studies using a wide range of different stimuli are needed to map the accuracy of trustworthiness decisions under varying conditions.

We investigate one such condition here, namely the accuracy of trustworthiness judgments when judgments are solely based on facial features. This approach is informative for two reasons. First, even though people often have access to other cues, which may allow them to make more accurate judgments, there are also many situations in which a person's facial appearance is either one of the only cues or a particularly salient cue. People often engage with strangers and, in the first moments of the interaction, tend to judge them solely based on their appearance. Moreover, facial photographs are a common feature of many decision-making environments, including social media platforms (e.g., Twitter), professional networking sites (e.g., LinkedIn), and the sharing economy (e.g., Airbnb). Second, ample evidence suggests that people rely on facial appearance, even when they have access to other cues (Jaeger et al., 2019; Olivola et al., 2014). To determine whether reliance on facial appearance helps or hinders people in making accurate predictions, the accuracy of judgments that are solely based on facial appearance needs to be isolated. This requires a highly controlled and standardized study design, such as the one used in the current experiments, to ensure that judgments are based on the cue in question (Cox et al., 2015).

At Harvard, the admit rates for typical African American applicants are on average over four times larger than if they had been treated as white; for typical Hispanic applicants the increase is 2.4 times

What the Students for Fair Admissions Cases Reveal About Racial Preferences. Peter Arcidiacono, Josh Kinsler & Tyler Ransom. NBER Working Paper 29964. Apr 2022. DOI 10.3386/w29964

Abstract: Using detailed admissions data made public in the SFFA v. Harvard and SFFA v. UNC cases, we examine how racial preferences for under-represented minorities (URMs) affect their admissions to Harvard and UNC-Chapel Hill. At Harvard, the admit rates for typical African American applicants are on average over four times larger than if they had been treated as white. For typical Hispanic applicants the increase is 2.4 times. At UNC, preferences vary substantially by whether the applicant is in-state or out-of-state. For in-state applicants, racial preferences result in an over 70% increase in the African American admit rate. For out-of-state applicants, the increase is more than tenfold. Both universities provide larger racial preferences to URMs from higher socioeconomic backgrounds.

Ungated: http://public.econ.duke.edu/~psarcidi/racialpref.pdf

Both genders applied self-deprecating double standards when viewing overweight and average-weight bodies; women, but not men, also showed self-deprecating double standards when viewing the ideal body and their own body

Giving a Body a Different Face—How Men and Women Evaluate Their Own Body vs. That of Others. Mona M. Voges, Hannah L. Quittkat, Benjamin Schöne and Silja Vocks. Front. Psychol., May 2 2022 | https://doi.org/10.3389/fpsyg.2022.853398

Abstract: Eating disorders affect women more than men. Women reportedly dislike their body shape more and appreciate it less than do men. One factor influencing body image might be the application of different standards for oneself than for other people when evaluating bodies. To investigate this possibility, we determined whether the application of double standards is different between men and women. We presented 57 women and 54 men (aged 18–30 and of average weight) with pictures of their own bodies and pictures of average weight, overweight, and “ideal” bodies attached to the participants’ own face and to another person’s face. Participants were instructed to evaluate their emotional reaction to the pictures and then rate the various pictures on aspects of attractiveness, body fat, and muscle mass. The degree of the double standard was defined as the difference between ratings of what appeared to be one’s own body and what appeared to be someone else’s according to the presented face. The analyses revealed, firstly, that both genders applied self-deprecating double standards when viewing overweight and average-weight bodies. Women, but not men, also showed self-deprecating double standards when viewing the ideal body and their own body. By contrast, men applied fewer double standards when viewing the ideal body and self-enhancing double standards when viewing their own body. The study suggests that young, average-weight men are more or less satisfied with their own bodies, whereas young, average-weight women tend to apply a stricter standard for themselves than for others, thus devaluing their own bodies. This vulnerability to body image is hypothesized as contributing to the prevalence of eating disorders in women.

Discussion

The present study was conducted to examine whether women differ from men in the application of double standards in body evaluation. Therefore, we presented the participants’ own bodies and average-weight, overweight, and ideal bodies, once with another face and once with the participant’s face. Women and men were asked to evaluate their emotional reaction regarding valence and arousal and to rate the bodies with regard to body attractiveness, body fat, and muscle mass. Double standard application was measured by the difference between the body ratings generated by the different faces.

First, our hypothesis that women and men would apply self-deprecating double standards in the case of an overweight body was confirmed. For both genders, self-deprecating double standards were observed on all dependent variables. Women and men rated their emotional reaction to an overweight body as more negative and with more arousal. They also rated the overweight body as less attractive, with more body fat, and with less muscle mass when the body had their own face compared to another person’s face. The double standards in valence, arousal, and body fat in the case of the overweight body were more self-deprecating than the double standards in valence, arousal, and body fat for the other body builds. These findings are in line with a previous study that employed cartoon-like body stimuli (Voges et al., 2019b) and might be related to negative stereotypes and stigma associated with overweight and obesity in Western society, e.g., obese people are often stigmatized as “careless,” “disorganized,” and “lazy” (Hu et al., 2018). The activation of self-related schemas through the presentation of one’s own face might result in stricter body evaluations, representing the participants’ rejection of overweight for their own bodies (Voges et al., 2019a).

Contrary to our hypothesis, women also showed self-deprecating double standards for other body builds—average-weight, ideal, and one’s own body—which is not in line with the findings of a previous study using cartoon-like body stimuli, which reported that women applied the same standard to the other images (Voges et al., 2019a). In contrast to the use of cartoon-like bodies in previous studies, participants in the present study evaluated real body stimuli (Voges et al., 2019b). This might have led to a better identification with the body stimuli and might have reinforced body schema activation, resulting in more pronounced double standards in women. Furthermore, as the present study also included women with a BMI of 25–30 kg/m2, the women had a higher average BMI than those in the aforementioned study, and they had higher body dissatisfaction and eating pathology than the sample in the previous study (Voges et al., 2019a). However, most women in the present sample (about 87%) had an average weight according to the WHO criteria, and the average BMI of 21.78 was, as in the previous study, in the lower-average weight category. Furthermore, body dissatisfaction and eating pathology were at an average and not notably different level compared to norms for young women (Paul and Thiel, 2005; Mond et al., 2006). Thus, the present results suggest that not only women with eating disorders, but also women without eating disorders, might apply stricter standards for themselves than for others regarding body evaluation, which might foster body dissatisfaction.

The hypothesis that men would show self-enhancing double standards in the case of an ideal body and one’s own body can be partially confirmed by the present findings. With the exception of a self-deprecating double standard in body attractiveness, men showed no double standards for the ideal body, which is not in line with previous findings with artificially created bodies (Voges et al., 2019b). However, in the case of one’s own body, men showed self-enhancing double standards in valence and body attractiveness and no self-deprecating double standards. Although men evaluated the ideal body as more attractive than their own body, identification with this body did not lead to self-enhancing double standards. Thus, young men might have internalized the idea that their own body “fits them well” and does not need to correspond to existing male body ideals in society. This would be in line with findings that men do not believe that the ideal male body is more attainable for themselves than for other men, as women do in the case of the female ideal (Buote et al., 2011). Moreover, this idea would further be consistent with the examined correlations of body appreciation and body dissatisfaction with the self-enhancing double standards in men.

Comparing women’s and men’s body evaluations, women rated in a more self-deprecating manner than did men and, in contrast to men, did not show a self-enhancing double standard for one’s own body. Possibly, female and male stereotypes might contribute to such gender differences in body evaluation (Voges et al., 2019b). According to stereotypes concerning male and female characteristics, men should be “independent,” “strong,” and “outstanding,” while women should be “agreeable” and “friendly” (Guimond et al., 2006). Such stereotypes might simplify self-enhancing evaluation patterns in men while hampering them in women (Meyers-Levy and Loken, 2015). In line with this, men engage more in positive body talk than women (Lin et al., 2021), for whom it seems to be normative to engage in negative fat talk, i.e., degrading the body shape and weight of oneself or others (Tompkins et al., 2009). Thus, women might internalize a devaluation of their own body, while men might be more predisposed to upvalue their own body.

To check whether double standards are associated with body dissatisfaction and body appreciation, we conducted correlation analyses. In line with our hypotheses, the results revealed some associations of body dissatisfaction and body appreciation with double standards in women and men. For women, the higher the body dissatisfaction and the lower the body appreciation, the more self-deprecating was the double standard in valence for one’s own body. Furthermore, the higher the body dissatisfaction, the more self-deprecating were the double standards in arousal and body fat for one’s own body and the double standard in body fat for the overweight body. For men, the higher the body dissatisfaction, the less self-enhancing were the double standards in arousal, body attractiveness, and body fat for one’s own body. Furthermore, as mentioned above, the higher the body appreciation, the more self-enhancing were the double standards in valence and body attractiveness for one’s own body. These findings suggest that double standards related to one’s own body are more directly linked to body dissatisfaction and body appreciation than double standards related to other bodies, as most correlations were found for double standards related to one’s own body and not to the other bodies. This corresponds to the notion that the visual representation of one’s own body is influenced by the attitudes toward one’s own body (Williamson et al., 2004; Maister et al., 2020) and that eating pathology is not linked to a generally distorted body perception or cognition but rather to a cognitive–affective distortion in evaluating one’s own body (Behrens et al., 2021). Thus, in addition to stricter standards for oneself, especially in body fat (Voges et al., 2018), eating pathology might be linked to a negative attitude toward one’s own body. With its idiosyncratic characteristics, one’s own body may not match one’s own standard, but may be viewed as more appropriate for other people.

Furthermore, for women, the association with double standards for the overweight body suggests that a stricter disapproval of overweight and obesity for oneself might also foster body dissatisfaction in average-weight women. The fact that no further associations of body dissatisfaction and body appreciation with double standards related to the other bodies (ideal, average-weight, overweight) were observed might also be partially explained by different cognitive reactions to these bodies leading to the same double standard. For example, self-deprecating double standards might emerge in persons with high body dissatisfaction because they generally devalue themselves compared to others and in persons with low body dissatisfaction, because they dislike imagining having the other body, and prefer their own body. Thus, in contrast to the double standards related to one’s own body, the associations between body dissatisfaction or body appreciation and the double standards related to the other bodies might not be so clear.

The present study is the first to examine double standards in body evaluation with photos of bodies including one’s own body and manipulating identification using different faces. By giving a body a different face, we were able to show that identity influences body evaluation differently in women and men. However, some limitations that might restrict the generalizability of the findings should be mentioned. Although the body stimuli were more realistic than those used in a previous study (Voges et al., 2019b), the stimulus material was standardized and gray-scaled, which likely limited the ecological validity. Furthermore, as we used photos of real persons, the bodies naturally differed somewhat in features other than body build (e.g., body height, skin features, body shape). However, for most body build categories, women and men rated the male and female bodies as equally attractive. As we did not assess persons with eating disorders, muscle dysmorphia, or severe body concerns, our results cannot be transferred to these clinical populations. Furthermore, as our study included a photo shoot in which participants wore their underwear, and participants were required to look at photos of their own body, women and men with high body dissatisfaction might have felt too daunted to participate. Based on previous findings with cartoon-like bodies (Voges et al., 2018) and the detected correlations of double standards with body dissatisfaction in this study, it might be assumed that double standards for one’s own body would be more self-deprecating in the case of participants with eating pathology, which should be examined in future studies. Furthermore, samples with a higher BMI, younger or older persons, or persons from different cultures might show different double standards in body evaluation, as body image has been found to differ across the lifespan (Quittkat et al., 2019), across BMI ranges (Calzo et al., 2012), and across cultures (Swami et al., 2010). Thus, the present results provide information about young, highly educated, and average-weight Caucasian women and men, and should be further examined in other samples.

Future studies could use experimental paradigms to clarify which mechanisms result in double standards and whether such double standards in body evaluation play a causal role in body image disturbances. A possible modification of the study design might be to measure eye movements during body evaluation in order to determine whether different identities result in differences in viewing patterns on the same body. Studies indicate that attentional biases may exist depending on identity, especially in individuals with eating disorders (Bauer et al., 2017) or body dysmorphic disorders (Waldorf et al., 2019). Furthermore, following designs for cognitive bias modification training (Dietel et al., 2020), participants could be trained to internalize double standards (e.g., “You have to work harder than others,” “Only the best is good enough for you,” “You have to be slim”), enabling it to be examined whether this manipulation results in more pronounced double standards in body evaluation and in higher body dissatisfaction. In a next step, cognitive bias modification training (Dietel et al., 2020) or evaluative conditioning paradigms (Glashouwer et al., 2018) could also be used to potentially reduce self-deprecating double standards. Furthermore, preventive strategies that emphasize the diversity and positive aspects of bodies, especially for women (Cohen et al., 2021), or seek to prevent widespread dysfunctional behaviors, such as fat talk (Mills and Fuller-Tyszkiewicz, 2017), or promote positive body talk (Alleva et al., 2021) might be promising. In particular, the newer body neutrality movement on social media which encourages women to attach less importance toward physical appearance might be a helpful approach (Cohen et al., 2021), as findings indicate that the evaluation of neutral characteristics is less biased by the identity of the person being assessed than the evaluation of very desirable or undesirable characteristics (John and Robins, 1993).

In sum, the present study extends previous findings of gender differences in applying double standards to self and other body evaluation. Women, relative to men, are self-depreciating. When their own face is attached to differently shaped bodies, they apply stricter standards of attractiveness, which may account for the prevalence of body image disturbances in women.

Following an incident of misconduct, female financial advisers are 20% more likely to lose their jobs and 30% less likely to find new jobs; gap is not driven by gender differences in occupation, productivity, nature of misconduct, or recidivism

When Harry Fired Sally: The Double Standard in Punishing Misconduct. Mark Egan, Gregor Matvos, and Amit Seru. Journal of Political Economy, Apr 2022. https://doi.org/10.1086/718964

Abstract: We examine gender differences in misconduct punishment in the financial advisory industry. There is a “gender punishment gap”: following an incident of misconduct, female advisers are 20% more likely to lose their jobs and 30% less likely to find new jobs, relative to male advisers. The gender punishment gap is not driven by gender differences in occupation, productivity, nature of misconduct, or recidivism. The gap in hiring and firing dissipates at firms with a greater percentage of female managers and executives. We also explore the differential treatment of ethnic minority men and find similar patterns of “in-group” tolerance.

Combining data from exams taken at Swedish military enlistment with earnings records from the tax register, we document an increase in the relative labor market return to logical reasoning skill as compared to vocabulary knowledge

Labor Market Returns and the Evolution of Cognitive Skills: Theory and Evidence Get access Arrow. Santiago Hermo, Miika Päällysaho, David Seim, Jesse M Shapiro. The Quarterly Journal of Economics, qjac022, Apr 19 2022. https://doi.org/10.1093/qje/qjac022

Abstract: A large literature in cognitive science studies the puzzling “Flynn effect” of rising fluid intelligence (reasoning skill) in rich countries. We develop an economic model in which a cohort’s mix of skills is determined by different skills’ relative returns in the labor market and by the technology for producing skills. We estimate the model using administrative data from Sweden. Combining data from exams taken at military enlistment with earnings records from the tax register, we document an increase in the relative labor market return to logical reasoning skill as compared to vocabulary knowledge. The estimated model implies that changes in labor market returns explain 37 percent of the measured increase in reasoning skill, and can also explain the decline in knowledge. An original survey of parents, an analysis of trends in school curricula, and an analysis of occupational characteristics show evidence of increasing emphasis on reasoning as compared to knowledge.

JEL J24 - Human Capital; Skills; Occupational Choice; Labor ProductivityJ31 - Wage Level and Structure; Wage DifferentialsO52 - Europe

Individual factors, particularly low status, and social forces, such as a high degree of status inequality, female empowerment, and the ease of coordination through social media, give rise to misogynistic extremism

Lindner, Miriam. 2022. “Alone Together and Angry: Misogynistic Extremism as Coalitional Bargaining for Sexual Access.” PsyArXiv. April 30. doi:10.31234/osf.io/pve8u

Abstract: Mass shooters, violent extremists, and terrorists, who are overwhelmingly male, exhibit misogynistic attitudes and a history of violence against women. Over the past few years, incels (“involuntary celibates”) have gathered in online communities to discuss their frustration with sexual/romantic rejection, espouse male supremacist attitudes, and justify violence against women and men who are more popular with women. Despite the link between misogyny and mass violence, and the recent emergence of online misogynistic extremism, theories and empirical research on misogynistic extremism remain scarce. I apply theorizing on the function of coalitional aggression as one of bargaining over collective conflicts of interest to the domain of sexual aggression and explore how sexual rejection can be framed as a grievance and make violence attractive. I show how individual factors, particularly low status, and social forces, such as a high degree of status inequality, female empowerment, and the ease of coordination through social media, give rise to misogynistic extremism.

The Gendered Consequences of Risk-Taking at Work: No evidence for overall gender differences in initial risk-taking

The Gendered Consequences of Risk-Taking at Work: Are Women Averse to Risk or to Poor Consequences? Thekla Morgenroth, Michelle K. Ryan, Cordelia Fine. Psychology of Women Quarterly, April 18, 2022. https://doi.org/10.1177/03616843221084048

Abstract: Women are seen as more risk-avoidant in the workplace, and some have argued that this contributes to occupational gender gaps. Across two correlational and three experimental studies (total N = 2280), we examined the role of consequences of workplace risk-taking in determining the likelihood of taking future risks at work. We found no evidence for overall gender differences in initial risk-taking, and women and men anticipated similar consequences for risks with which they have no experience. However, this stands in contrast to the consequences of risk-taking they have experienced. Here, men reported on average more positive consequences, even for those risks that are more normative for women, translating into a higher likelihood of taking the same risks again. When faced with the same consequences, women and men were equally likely to take the same risks again. Our findings challenge the simple assumption that women are averse to workplace risks and suggest that if and when women do avoid risks, it is because their risk-taking leads to less rewarding consequences. Workplace gender equality initiatives should therefore tackle any inequities of consequences rather than encouraging women to “lean in” and take more risks. Additional online materials for this article are available on PWQ’s website at https://journals.sagepub.com/doi/suppl/10.1177/03616843221084048.

Keywords: risk-taking, risk-aversion, gender, gender differences, workplace gender equality

Warfare among foragers who lived among foragers and were not subject to control by a state: Conflict occurred on all scales ranging from small-scale raids to battles involving hundreds of warriors on each side; large-scale conflict caused many casualties and much mortality; larger scale conflict was more common between members of different ethnolinguistic or tribal groups than within such groups

Large-scale cooperation in small-scale foraging societies. Robert Boyd, Peter J. Richerson. Evolutionary Anthropology: Issues, News, and Reviews. April 29 2022. https://doi.org/10.1002/evan.21944

Abstract: We present evidence that people in small-scale mobile hunter-gatherer societies cooperated in large numbers to produce collective goods. Foragers engaged in large-scale communal hunts and constructed shared capital facilities; they made shared investments in improving the local environment; and they participated in warfare, formed enduring alliances, and established trading networks. Large-scale collective action often played a crucial role in subsistence. The provision of public goods involved the cooperation of many individuals, so each person made only a small contribution. This evidence suggests that large-scale cooperation occurred in the Pleistocene societies that encompass most of human evolutionary history, and therefore it is unlikely that large-scale cooperation in Holocene food producing societies results from an evolved psychology shaped only in small-group interactions. Instead, large-scale human cooperation needs to be explained as an adaptation, likely rooted in distinctive features of human biology, grammatical language, increased cognitive ability, and cumulative cultural adaptation.

 5.2.4 Iñupiaq in northwestern Alaska

During the first half of the 19th 560 century, Iñupiaq groups in western Alaska conducted regular

 large-scale warfare against members of other Iñupiaq groups, Athabaskan speakers to the east, and

Chukchi people on the Asian side of the Bering Strait. Our knowledge of these events comes from

Iñupiaq ethnohistory collected by the anthropologist Ernest “Tiger” Burch100 563 who interviewed Iñupiaq elders about 19th 564 century Iñupiaq life, conflict and alliance. By collecting and collating many accounts of the same events, he was able to create a picture of Iñupiaq life before extensive contact with Europeans and North Americans.

The Iñupiaq economy was based on fishing and hunting large game, mainly caribou and marine

 mammals. They lived in villages during the fall and winter, and then moved to fishing and hunting camps in the spring and summer. Population densities were about 1 person per 20 square kilometers, at the low end of the forager range. Villages ranged in size from 8 to 160 people, but 80% had less than 32 people.

People were collected into territorial groups that Burch refers to as nations. In the region

around Kotzebue Sound there were 10 nations with an average population size of 470 people and

average territory size of 8600 km2.

Burch100:140 recorded accounts of 77 raids and battles that occurred in the first half of the 19th 574

century. Like other foraging groups, attackers preferred surprise, nighttime raids. These occurred mainly in the fall because low temperatures meant that people would be inside at night, frozen rivers made travel easier, and the lack of snow made it difficult to track retreating raiders. Raiding parties armed with bows, lances and knives travelled long distances, sometimes as much as 300km each way, and never less than 80km.

 

 Villages were centered around a community hall or qargi where men spent much of their evenings. Attackers hoped to surprise all the men in the qargi and kill them as they exited.

 If the raid was successful, attackers killed everybody in the village. Sometimes young women were taken as slaves, but usually they were raped, tortured and killed100:104 582

 The threat of raids prompted people to take defensive action. Some villages had defensive

 stockades, and others were surrounded by fields of sharpened caribou bones driven into the ground,

 much like the punji sticks used by Viet Cong fighters. They also built escape tunnels into the qargi.

Raiders were sometimes detected and ambushed themselves.

 Small villages could be attacked by  raiding parties numbering 10 or 20 warriors. However, Iñupiaq sometimes attacked larger villages, and this required much larger raiding parties. It was more difficult to feed a large war party during travel, and larger villages were harder to approach undetected, but nonetheless, raids on large villages did occur.

Burch gives detailed accounts of several large raids. For example, raiding party of 350−400 men attacked a village of about 600 people. The attackers wore camouflaged clothing and came bare593 footed to minimize the chance their approach would be heard. However, they were spotted, and the

 Point Hope villagers poured out and attacked the raiders who retreated onto a field studded with

 caribou spikes rendering many of them helpless. Their comrades fled leaving the injured to be killed by the defenders.

Sometimes the Iñupiaq engaged in large open battles. This could occur when a large raiding party was detected, but sometimes they took place when the animosity between two nations had reached a boiling point.

In open battles, the two sides formed battle lines with the best archers on the flanks. Then the two sides would exchange archery fire, sometimes for hours. If one side was getting the worst of it, they might sometimes flee, experiencing serious casualties. Sometimes the two  sides would close and engage in hand to hand combat armed with lances and knives.

Men prefer dimorphism in female faces more than women do, wom prefer dimorph in male faces more than men; both men&wom prefer symmetric faces equally in same- & opposite-sex targets; no indication pathogen cues activate either preference

Re-evaluating the relationship between pathogen avoidance and preferences for facial symmetry and sexual dimorphism: A registered report. Joshua M. Tybur et al. Evolution and Human Behavior, Volume 43, Issue 3, May 2022, Pages 212-223. https://doi.org/10.1016/j.evolhumbehav.2022.01.003

Abstract: Over the past decade, a small literature has tested how trait-level pathogen-avoidance motives (e.g., disgust sensitivity) and exposure to pathogen cues relate to preferences for facial symmetry and sexual dimorphism. Results have largely been interpreted as suggesting that the behavioral immune system influences preferences for these features in potential mates. However, findings are limited by small sample sizes among studies reporting supportive evidence, the use of small stimulus sets to assess preferences for symmetry and dimorphism, and design features that render implications for theory ambiguous (namely, largely only investigating women's preferences for male faces). Using a sample of 954 White young adult UK participants and a pool of 100 White young adult stimuli, the current registered report applied a standard two-alternative forced-choice approach to evaluate both men's and women's preferences for both facial symmetry and dimorphism in both same- and opposite-sex targets. Participants were randomly assigned to either a pathogen prime or a control prime, and they completed instruments assessing individual differences in pathogen avoidance (disgust sensitivity and contamination sensitivity). Results revealed overall preferences for both facial symmetry and dimorphism. However, they did not reveal a relation between these preferences and disgust sensitivity or contamination sensitivity, nor did they reveal differences in these preferences across control and pathogen prime conditions. Null results of pathogen-avoidance variables were consistent across participant sex, target sex, and interactions between participant sex and target sex. Overall, findings cast doubt on the hypothesis that pathogen-avoidance motives influence preferences for facial symmetry or dimorphism.

Keywords: DisgustHealthMasculinitySymmetryMate preferencesBehavioral immune system

4. Discussion

The current registered report evaluated the relation between pathogen-avoidance motives and preferences for facial symmetry and dimorphism. It sought to test whether any such relation applied to preferences for both same- and opposite-sex targets – a phenomenon that might result from these features being interpreted as cues to infectiousness – or only in opposite sex targets – a phenomenon that might result from these features being treated as information regarding indirect benefits (i.e., genes that increase offspring fitness). Using a set of 100 target faces and a sample of 954 participants, we did not detect evidence consistent with either perspective. That is, we did not detect a relation between individual differences measures (pathogen disgust sensitivity and germ aversion) and general preferences for facial symmetry or dimorphism, nor did we detect a difference in this relation across same- and opposite-sex faces. Similarly, we did not detect an effect of a pathogen prime (relative to a control prime) on preferences for symmetry or dimorphism, nor did we detect differences in such preferences across same- versus opposite-sex targets. We discuss the implications of these findings for both the behavioral immune system literature and the face preferences literature below.

4.1. Implications for the behavioral immune system and face preferences

The null results observed here have some implications for how we view the functional specificity of the behavioral immune system. Current thinking conceptualizes the behavioral immune system as a suite of psychological mechanisms that monitor the environment for features that correlate with pathogen presence (i.e., cues to pathogens) and, when those features are detected, motivates behaviors that reduce the likelihood of infection (Ackerman et al., 2018; Schaller & Duncan, 2007; Lieberman & Patrick, 2014; Tybur & Lieberman, 2016). Byproducts of infection in conspecifics are some of the best candidates for such cues. And, indeed, people can distinguish between individuals experiencing an immune response from those who are not (Arshamian et al., 2021), and they avoid (and are sometimes disgusted by) individuals with rashes, ulcers, and pustules on their faces – some of the key symptoms of communicable diseases (Curtis et al., 2004; Kurzban & Leary, 2001; Oaten et al., 2011).

Following the logic presented in previous work investigating the relation between pathogen avoidance and preferences for facial symmetry and/or dimorphism, the hypotheses tested here were based on the idea that facial symmetry and dimorphism provide information regarding health, and that the behavioral immune system should motivate preferences for healthy targets (and, perhaps especially, healthy mates). However, features perceived as “healthy” need not be treated as information regarding infection threat. Health can refer to absence of infectious disease, but it can also refer to a number of other aspects of condition, including the absence of non-contagious parasites, the absence of non-contagious metabolic diseases, the absence of injury, the absence of psychopathology, etc. Just as the behavioral immune system should not be expected to influence fear of tigers or heights, both of which can be thought of as preserving some aspect of “health”, it should not be expected to influence preferences for facial symmetry or dimorphism unless those features act as cues to infectiousness. Given that the structural features that give rise to variation in facial symmetry and dimorphism are fairly stable across the lifespan – and given recent findings suggesting that dimorphism and symmetry (along with multiple other aspects of facial appearance) have poor validity as cues to multiple dimensions of health that might relate to infection proneness (Foo, Simmons, & Rhodes, 2017, Cai et al., 2019; see Jones, Holzleitner, & Shiramizu, 2021) – they are unlikely candidates as infection cues. These considerations (and, naturally, the results of the current study) raise questions regarding interpretations of earlier findings that pathogen avoidance relates to preferences for facial symmetry and dimorphism.

4.2. Implications regarding preferences for facial symmetry and dimorphism

Although this investigation was designed to evaluate the relation between pathogen avoidance and preferences for facial symmetry and dimorphism, its sample size and other design features (e.g., assessment of both same- and opposite-sex preferences for both facial symmetry and dimorphism) can contribute to the field's understanding of preferences for symmetry and dimorphism, at least in the population sampled from here. Consider, for example, comparing the current results with those reported by Little, Jones, DeBruine, and Feinberg (2008), who inferred that symmetry and dimorphism provide common information based on the observation that preferences for facial dimorphism correlate with preferences for facial symmetry. The current study similarly detected a positive relation between preferences for facial symmetry and preferences for facial dimorphism (see Table S1). It also replicates other findings reported by Little et al.: that men prefer dimorphism in female faces more than women do, and that women prefer dimorphism in male faces more than men do. However, it did not replicate a third finding from the same paper: that symmetry preferences are contingent on the sex of the rater and the target. Instead, we found that symmetric faces were preferred equally in same-sex and opposite-sex targets, for both men and women. The current data might prove useful for evaluating the robustness of other findings in the face preferences literature.

4.3. Limitations and future directions

4.3.1. Statistical power and potential false negatives

Non-significant results can emerge for multiple reasons, including experimenter error or participant inattention. Multiple aspects of our findings suggest that neither of these factors explains the critical null findings observed here. The fact that we detected global preferences for facial symmetry and facial dimorphism – with the latter preference moderated by participant sex and target sex – suggests that participants were (1) able to detect these features and (2) preferred them in a manner consistent with past studies sampling from the same population. Other incidental findings discount the null results reflecting systematic errors in data collection. For example, the sex difference in pathogen disgust sensitivity observed here (d = .41) was virtually identical to the meta-analyzed sex difference observed in a study of 11,501 participants across 30 nations (d = .41) (Tybur et al., 2016).

Even without experimenter error or participant inattention, null results can still reflect Type II errors. In random effects designs such as the one employed here, the probability of making such errors is influenced by myriad factors, including (1) the magnitude of the fixed effect(s), (2) the number of participants, (3) the number of stimuli, (4) variance accounted for by participants, (5) variance accounted for by stimuli, (6) variance in the relation between participant-level individual differences (e.g., pathogen disgust sensitivity) and preferences across different stimuli, etc. We aimed to minimize the probability of making such Type II errors, even if effect sizes were small, by (1) having a large sample size (N = 954), (2) having a large pool of stimuli (N = 100), and (3) manipulating multiple factors within-participants. However, because we were unable to model all random effect components in our power analyses, results from these power analyses might be imprecise, and we cannot state with confidence the effect sizes that we had adequate power (>80%) to detect. Nevertheless, inspection of the 95% confidence intervals around effect size estimates can provide an idea of the uncertainty in our parameter estimates and the plausible upper bounds of population-level effect sizes (see Table 2). These confidence intervals are narrow and largely centered around zero. Inspection of the confidence intervals collapsing across stimuli can also be informative (see Tables S1–S3), since most prior studies in this literature have not used random effects analyses. Using this approach, the upper limit of the 95% confidence interval for the main effect of pathogen disgust sensitivity on facial dimorphism preferences was r = .12, and the upper limit of the 95% confidence interval for the relation between pathogen disgust sensitivity and facial symmetry preferences was r = .08. Given the nature of the indirect benefits hypothesis, confidence intervals around simple effects within participant sex by target sex interactions (for both symmetry and dimorphism preferences, and for both pathogen disgust and germ aversion as predictors) can also be informative, especially concerning cross-sex preferences. For men, none of the upper limits of these confidence intervals exceeded r = .15; for women, none exceeded r = .07. In total, these results suggest that any relations we failed to detect are likely to be small in magnitude. Future studies on this topic should be designed to detect effect sizes no larger than the upper limits of these confidence intervals.

4.3.2. Validity of the dependent measure and stimuli

In line with previous studies in this literature, we investigated the degree to which pathogen-avoidance motives relate to attraction to facial symmetry and sexual dimorphism. Perceptions of attractiveness need not fully regulate the physical proximity, direct contact, or indirect contact that influences pathogen transmission, though. Recent studies in the pathogen-avoidance literature have asked participants how comfortable they would be with physical contact with a target (e.g., Van Leeuwen & Petersen, 2018), and one of these studies found only a modest relationship between target facial attractiveness and contact comfort (Tybur, Lieberman, Fan, Kupfer, & de Vries, 2020). Although the current study did not detect a relation between pathogen avoidance and attraction to facial symmetry or dimorphism, future research could better test whether people are more averse to infection-risky acts with individuals with low dimorphism or low symmetry faces (cf. Kupfer, 2018; Ryan et al., 2012).

As is standard in this literature, we used a two-alternative forced-choice response format. Recent work has suggested that this method partially assess face matching ability rather than variation in preferences (Lewis, 2020), and that it can produce results that differ from those obtained with paradigms in which individual faces are rated for attractiveness (Jones & Jaeger, 2019; Lee, De La Mare, Moore, & Umeh, 2021). Also following standard procedures in this literature, we manipulated base faces to be 50% more similar to male or female prototypes (for the dimorphism manipulation) or 50% more or less similar to a perfectly symmetric version of the base face. We cannot rule out the possibility that pathogen avoidance would relate to preferences for facial dimorphism or symmetry if transformations were more or less extreme.

4.3.3. Effects of the COVID-19 pandemic

We collected data in May 2021, after approximately 4,500,000 COVID-19 cases and 125,000 deaths had been confirmed in the UK in the 14 months since the pandemic began (Roser, 2021). Some recent work has argued that the SARS-CoV-2 outbreak has increased pathogen disgust sensitivity (Boggs, Ruisch, & Fazio, 2022; Stevenson, Saluja, & Case, 2021). Such increases, if sufficiently strong, could attenuate the relation between pathogen disgust sensitivity and preferences for facial symmetry or dimorphism. Our data give no reason to suspect that pathogen disgust sensitivity was unusually high in the population we sampled from, though. The mean observed here was virtually indistinct (and, if anything, slightly lower) from that in the sample of U.S. college students (N = 507) used to validate the Three-Domain Disgust Scale (Tybur et al., 2009) and that in a large (N = 7166) online English-speaking sample recruited shortly before the pandemic (O'Shea, DeBruine, & Jones, 2019) (see the online supplement for more details). There are also reasons to question whether, how, and why the presence of SARS-CoV-2 would affect how the behavioral immune system detects or processes cues to pathogens. Like many other respiratory pathogens, SARS-CoV-2 is largely spread via invisible respiratory droplets and aerosols expelled when (often asymptomatic or pre-symptomatic) individuals breath, talk, or sing (Greenhalgh et al., 2021). Those infected with SARS-CoV-2 typically exhibit symptoms similar to those caused by the myriad endemic respiratory pathogens that circulated widely before the COVID-19 pandemic (e.g., coughing, sneezing, headache, fatigue, fever) (Tostmann et al., 2020). And, while SARS-CoV-2 causes serious illness in some people, its appearance coincided with the virtual elimination of many other respiratory viruses from circulation (Yeoh et al., 2021). These reasons raise doubts that the pandemic conditions that began in early 2020 would affect the behavioral immune system, at least via increases in the presence of detectable transmission risks, changes in observable illness symptoms in others, or increases in encounters with pathogens oneself (Ackerman, Tybur, & Blackwell, 2021). Future work can clarify whether, how, and why the pandemic affects the behavioral immune system in other manners.

4.3.4. Generalizability to other populations

The current study sampled from a population of young adult (<35) heterosexual White individuals from the UK, and it assessed attraction toward young adult White targets. Some findings indicate that preferences for facial dimorphism – perhaps especially in male targets – varies across ecologies (DeBruine, Jones, Crawford, Welling, & Little, 2010; Marcinkowska et al., 2019; Scott et al., 2014), as do preferences for at least some other dimensions of facial appearance (e.g., coloration; Han et al., 2018). Hence, our findings might not generalize to other populations. However, most studies that have reported relations between pathogen avoidance and preferences for facial symmetry or dimorphism have sampled from similar populations and assessed attraction toward similar targets (though see Saribay et al., 2021 and Zheng et al., 2016). Future work could certainly test whether pathogen avoidance relates to such preferences in other populations, even if such a relationship does not exist in the population sampled from here.

4.3.5. Validity of priming method and concluding thoughts

Most studies in the behavioral immune system literature assess individual differences in pathogen-avoidance motives using either the Perceived Vulnerability to Disease Scale or the Three-Domain Disgust Scale (Oosterhoff, Shook, & Iyer, 2018; Tybur et al., 2014). Multiple studies have clarified the validity of these instruments (e.g., Duncan et al., 2009; Tybur et al., 2009). There is less consistency in approaches used to experimentally manipulate pathogen-avoidance motives and, relatedly, less evidence supporting the validity of these procedures. For example, studies have reported that each of the following experimental manipulations produces effects consistent with behavioral immune system hypotheses: (1) asking participants to consciously reflect upon past experiences with infection (e.g., Moran et al., 2021; Murray, Kerry, & Gervais, 2019); (2) exposing participants to olfactory cues to pathogens (e.g., Tybur, Bryan, Magnan, & Hooper, 2011); (3) having participants read essays describing pathogen-risky situations (e.g., White, Kenrick, & Neuberg, 2013); (4) having participants complete a disgust sensitivity instrument immediately before the dependent measure (e.g., Lee & Zietsch, 2011; Navarrete & Fessler, 2006; Watkins et al., 2012); and (5) exposing participants to disgust-eliciting images or slideshows showcasing pathogen risks (e.g., Faulkner, Schaller, Park, & Duncan, 2004; Hill, Prokosch, & DelPriore, 2015; Mortensen, Becker, Ackerman, Neuberg, & Kenrick, 2010; Park, Schaller, & Crandall, 2007). Using a combination of those last two approaches – methods used in studies that have reported effects of pathogen primes on preferences for facial symmetry or dimorphism (Ainsworth & Maner, 2019; Little et al., 2010; Watkins et al., 2012; Young et al., 2011) – we did not detect an effect of the priming manipulation. Other recent studies have similarly reported not detecting effects of pathogen primes on, among other things, conformity (Van Leeuwen & Petersen, 2021), political attitudes (Shook & Oosterhoff, 2020), moral sentiments (Makhanova, Plant, Monroe, & Maner, 2019), and attitudes toward immigrants (Ji, Tybur, & van Vugt, 2019). Following these null findings, the behavioral immune system literature would benefit from large-scale, registered, collaborative work using multiple priming approaches to test the same hypothesis. Such an endeavor would be valuable for multiple reasons. Like the current study, it could be used to replicate studies that used methods that, in retrospect, might not be as robust as originally assumed. It could also give an unbiased assessment of the effect sizes that researchers should expect from priming methods; such an assessment would prove valuable for future study designs. And it could indicate which of the multiple manipulations used in the literature – from images to essays to odors – give rise to the largest of such effect sizes. In sum, taking a look at the methods and results used in past behavioral immune system work can improve future developments in this area.