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Humans’ extraordinary intelligence seems to extend beyond the needs for survival. One theory to explain this surplus intelligence is that it evolved via sexual selection as a fitness indicator to advertise genetic quality to prospective mates. Consistent with this idea, self-reported mate preferences suggest intelligence is valued across cultures. Yet, as the validity of these self-reports has been questioned, it remains unclear whether objectively assessed intelligence is indeed attractive. We analysed data from two studies to test this key premise of the sexual selection theory of intelligence. In Study 1, 88 target men had their intelligence measured and based on short video clips were rated on intelligence, funniness, physical attractiveness and mate appeal by 179 women. In Study 2 (N = 729), participants took part in 2 to 5 speed-dating sessions in which their intelligence was measured and they rated each other’s intelligence, funniness, and mate appeal. Measured intelligence did not predict increased mate appeal in either study, whereas perceived intelligence and funniness did. More intelligent people were perceived as more intelligent, but not as funnier. Results suggest that intelligence is not important for initial attraction, which raises doubts concerning the sexual selection theory of intelligence.
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Rule breaking behavior in sports (e.g., fouls) can impact the outcome of games, tournaments, or even whole seasons. Although personality traits have been related to different forms of rule breaking behavior across fields, it has hardly been investigated whether personality traits predict rule breaking behavior in sports. We ran a longitudinal study with 242 (semi-)professional basketball players. Specifically, we measured personality traits prior to the start of the season and official foul statistics per player during the season. Out of the basic personality traits from the HEXACO Model of Personality, Conscientiousness accounted for a substantial amount of variability in the committed/called fouls, whereas no robust relations with other traits or a sports-oriented personality trait (i.e., Sports Mental Toughness) were found.
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Objectives When judging a male speakers ’ likelihood to act sexually unfaithful in a committed relationship, listeners rely on the speakers ’ voice pitch such that lower voice pitch is perceived as indicating being more un faithful. In line with this finding, a recent study (Schild et al. , 2020 ) provided first evidence that voice pitch might indeed be a valid cue to sexual infide lity in men. In this study, male speakers with lower voice pitch, as indicated by lower mean fundamental frequency (mean F0), were actually more likely to report having been sexu ally unfaithful in the past. Although these results fit the literature on voca l perceptions in contexts of se xual selection, the study was, as stated by the authors, underpowered. Further, the study solely focused on male speakers, which leaves it open whether these findings are also transferable to female speakers. Methods We reanalyzed three datasets (Asendorpf et al. , 2011 ; Penke and Asendorpf , 2008 ; Stern et al., 2020 ) that include voice recordings and infidelity data of overall 865 individuals (63,36% female) in order to test the replicability of and further extend past research. Results A significant negative link between mean F0 and self-reported infidelity was found in only one out of two datasets for men and only one out of three datasets for women. Two meta-analyses (accounting for the sample sizes and including data of Schild et al., 2020 ), however, suggest that lower mean F0 might be a valid indicator of higher probability of self-reported infidelity in both men and women. Conclusions In line with prior research, higher masculinity, as indicated by lower mean F0, seems to be linked to self-re ported infidelity in both men and women. However, given methodological shortcomings, future studies shoul d set out to further delve into these findings.
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Over the last ten years, Oosterhof and Todorov’s valence-dominance model has emerged as the most prominent account of how people evaluate faces on social dimensions. In this model, two dimensions (valence and dominance) underpin social judgments of faces. Because this model has primarily been developed and tested in Western regions, it is unclear whether these findings apply to other regions. We addressed this question by replicating Oosterhof and Todorov’s methodology across 11 world regions, 41 countries, and 11,481 participants. When we used Oosterhof’s and Todorov’s original analysis strategy, the valence-dominance model generalized across regions. When we used an alternative strategy that allowed for a more optimal number of correlated latent factors, we observed much less generalization. These results underscore how each analysis strategy embeds substantive assumptions that can strongly influence theoretical conclusions.
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Research into the characteristics of attractive women’s voices has focused almost exclusively on associations with fundamental or formant frequencies. A recent study of a small sample of voices used a bottom-up approach to identify acoustic characteristics associated with women’s vocal attractiveness, finding that many acoustic characteristics other than fundamental or formant frequencies predicted women’s vocal attractiveness. Here we will replicate their methodology with a much larger sample of voices (N = 450) in order to identify vocal characteristics that reliably predict women’s vocal attractiveness. Identifying such traits will provide new insights into and avenues for study of the possible function of vocal attractiveness.
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Successful emotion recognition is a key component of human socio-emotional communication skills. However, little is known about the factors impacting males’ accuracy in emotion recognition tasks. This pre-registered study examined potential candidates, focusing on the modality of stimulus presentation, emotion category and individual baseline hormone levels. In an additional exploratory analysis, we examined the association of testosterone x cortisol interaction with recognition accuracy and reaction times. We obtained accuracy and reaction time scores from 282 males who categorized voice, face and voice-face stimuli for nonverbal emotional content. Results showed that recognition accuracy was significantly higher in the audio-visual than in the auditory or visual modality. While Spearman’s rank correlations showed no significant association of testosterone(T) with recognition accuracy or with response times for specific emotions, the logistic and linear regression models uncovered some evidence for a positive association between T and recognition accuracy as well as between cortisol (C) and reaction time. In addition, the overall effect size of T by C interaction with recognition accuracy and reaction time was significant, but small. Our results establish that audio-visual congruent stimuli enhance recognition accuracy and provide novel empirical support by showing that the interaction of testosterone and cortisol relates to males’ accuracy and response times in emotion recognition tasks.
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Facial fluctuating asymmetry (FA), presumably a proxy measure of developmental instability, has been proposed to inversely relate to vocal attractiveness, which may convey information on heritable fitness benefits. Using an improved method of measuring facial FA, we sought to replicate two recent studies that showed an inverse correlation of facial FA with vocal attractiveness. In two samples of men (N = 165) and women (N = 157), we investigated the association between automatically measured facial FA based on 3D face scans and male and female observer-rated attractiveness of voice recordings. No significant associations were found for men or women, also when controlling for facial attractiveness, age and BMI. Equivalence tests show that effect sizes were significantly smaller than previous meta-analytic effects, providing robust evidence against a link of facial FA with vocal attractiveness. Thus, our study contradicts earlier findings that vocal attractiveness may signal genetic quality in humans via an association with FA.
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In psychological science, egocentered social networks are assessed to investigate the patterning and development of social relationships. In this approach, a focal individual is typically asked to report the people they interact with in specific contexts and to provide additional information on those interaction partners and the relationships with them. While egocentered social networks hold considerable promise to investigate various interesting questions at the heart of relationship science and beyond, their implementation can be challenging. This tutorial provides researchers with detailed instructions on how to set up a study involving egocentered social networks online using the open-source software formr. By including a fully-functional study template for the assessment of social networks and extensions to this design, we hope to equip researchers from different backgrounds with the tools necessary to collect social network data tailored to their research needs.
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Objectives Although sports team members often value their teams highly, they sometimes make mistakes and thereby unintentionally put their teams at a disadvantage. Thus, they should be motivated to compensate for their mistake to resolve this discrepancy. To test this hypothesis, we studied whether professional soccer players compensate for their own goals by scoring regular goals in the same game (Study 1) and possible processes underlying such compensation efforts (Study 2). Design In Study 1, we compared how frequently prior own goal scorers scored a regular goal in the same game to (a) their expected goal scoring frequencies and (b) their probabilities to score a regular goal following a regular goal by the opposing team. In Study 2, we investigated four possible processes underlying the expected compensatory efforts. Method We analyzed all own goals from the first fifty years of the German Bundesliga (N = 889) and possible ensuing regular goals by the own goal scorer. Moreover, we surveyed amateur soccer players about four motives: group performance, individual performance, individual public image, and group public image. Results Following their own goals, professional soccer players are particularly likely to score regular goals in the same game (i.e., a compensatory own goal effect). Presumably, they primarily do so to secure a good group performance, but the other motives also play a role. Conclusions Group members who make highly visible mistakes are motivated to compensate for the disadvantage they caused. Presumably, they mainly do so to secure a good team performance.
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Objective: Although it is widely assumed that men’s sexual desire and interest in casual sex (i.e., sociosexual orientation) are linked to steroid hormone levels, evidence for such associations is mixed. Methods: We tested for both longitudinal and cross-sectional relationships between salivary testosterone, cortisol, reported sexual desire and sociosexuality in a sample of 61 young adult men, each of whom was tested weekly on up to five occasions. Results: Longitudinal analyses showed no clear relationships between steroid hormones and self-reported sexual desire or sociosexual orientation. Cross-sectional analyses showed no significant associations between average hormone levels and self-reported sexual desire. However, some aspects of sociosexuality, most notably desire for casual sex, were related to men’s average hormone levels. Men with higher average testosterone reported greater desire for casual sex, but only if they also had relatively low average cortisol levels. Conclusions: Our results support a Dual Hormone account of men’s sociosexuality, in which the combined effects of testosterone and cortisol predict the extent of men’s interest in casual sex. However, we did not detect compelling evidence for an association of within-subject hormone shifts and sexual desire or sociosexual orientation.
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* Christoph Schild and Julia Stern share the first authorship. Previous research suggests that judgments about a male speaker’ s trustworthiness v ary due to the speaker’s voice pitch ( mean F0 ) and differ across domain s . M ixed results in terms of the direction and extent of such effects have been reported , however . Moreover, no study so far has investigated whether men’s mean F0 is , indeed, a valid cue to their self - reported and behavioral trustworthiness , and whether trustworthiness judgments are accurate. W e tested the relation between mean F0 and actual general, economic and mating - related trustworthiness in 181 men, as well as t rustworthiness judgments of 95 perceivers across all three domain s. Analyses show that men’s mean F0 is not related to Honesty - Humil ity (as a trait indicator of general trustworthiness) , t rustworthy intentions, or trust game behavior , suggesting no relation of mean F0 to general or economic trustworthiness. In contrast, results suggest that mean F0 might be related to mating - related trustworthiness (as indicated by self - reported relationship infidelity) . However, l ower mean F0 was judge d as more trustworthy in economic, but less trustworthy in mating - related domain s and rather weakly related to judgments of general trustworthiness . Trustworthiness j udgments were not accurat e for general or economic trustworthiness , b ut exploratory analyses sugges t that women might be able to accurately judge men’s relationship infidelity based on their voice pitch . Next to these analyses, w e report exploratory analyses involving and controlling for additional voice parameters .
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Gangestad et al. (this issue) recently published alternative analyses of our open data to investigate whether women show ovulatory shifts in preferences for men’s bodies. They argue that a significant three-way interaction between log-transformed hormones, a muscularity component, and women’s relationship status provides evidence for the ovulatory shift hypothesis. Their conclusion is opposite to the one we previously reported (Jünger et al., 2018). Here, we provide evidence that Gangestad et al.’s differing conclusions are contaminated by overfitting, clarify reasons for deviating from our preregistration in some aspects, discuss the implications of data-dependent re-analysis, and report a multiverse analysis which provides evidence that their reported results are not robust. Further, we use the current debate to contrast the risk of prematurely concluding a null effect against the risk of shielding hypotheses from falsification. Finally, we discuss the benefits and challenges of open scientific practices, as contested by Gangestad et al., and conclude with implications for future studies.
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Recent studies suggest that both facial and bodily dominance promote high status positions and predict status-seeking behaviors such as aggression and social dominance. An evolutionarily relevant context in which associations between these dominance signals and status outcomes may be prevalent are face-to-face status contests. The present study examined whether facial and bodily dominance predicted success in dyadic competitions (one physical discipline, arm wrestling, and three nonphysical disciplines) in men (N = 125) in a controlled laboratory setting. Men’s bodies and faces were independently rated for physical dominance, and associations of these ratings with contest outcomes as well as mediating and moderating variables (such as physical strength, body height, trait dominance, baseline and reactive testosterone) were examined. Both facial and bodily dominance positively predicted success in the physical discipline, mediated by physical strength, but not in the three nonphysical disciplines. Our findings demonstrate that facial and bodily physical dominance may be honest signals for men’s formidability and hence status potential, at least in a physically competitive context.
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Animal social bonds are defined as stable, equitable and strong affiliative and cooperative relationships similar to human friendships. Just as human friendships, social bonds are thought to function as alliances that generate adaptive benefits via support in critical situations. In humans, similarity in many sociodemographic, behavioural and intrapersonal characteristics leads to trust and is predictive of friendships. Specifically, personality homophily, that is the tendency of individuals to form social bonds with others who have a similar personality, may increase predictability and facilitate trust and reciprocity among partners with compatible behavioural tendencies. While evidence for social bonding in nonhumans is accumulating, far less is known about its predictors. Here, personality homophily effects on the formation and maintenance of social bonds are shown in twenty-four wild male Assamese macaques (Macaca assamensis), at Phu Khieo Wildlife Sanctuary, Thailand. Dyadic bond strength increased with increased similarity in the trait Connectedness (i.e. frequent and diverse neighbours in 5m proximity and pronounced social tolerance, as high rates of friendly approaches to and by others). To differentiate whether homophily indeed predicted bond formation or whether bonded males’ personalities became more similar over time, we tested the stability of the connectedness traits in a subset of immigrating males that had to form new bonds. Connectedness in these males remained stable suggesting that males do not adapt their personality to their partner. Our results support the idea of a shared evolutionary origin of homophily as a partner choice strategy in human and non-human animals. The main selective advantage of personality similarity in animal social bonds may result from a more reliable cooperation among individuals with similar cooperative behavioural tendencies.
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In nonhuman animals, individuals of the same sex and age differ in their behavior patterns consistently across time, comparable with human personality differences. To draw conclusions about the adaptive value of behavior traits, it is essential to study them in the wild where animals are subject to the ecological pressures that promoted the evolution of behavior strategies. This study was conducted in the Phu Khieo Wildlife Sanctuary, Thailand, on 4 groups of habituated wild Assamese macaques by observers who had familiarized themselves with the subjects over the course of an ongoing long-term study. We used a multimethod approach enabling the most comprehensive understanding of variation in stable interindividual differences in a species-typical ecological setting. We combined trait ratings (TRs), assessed with observer-report questionnaires (54-item Hominoid Personality Questionnaire) of 107 individuals of diverse age-sex classes, with behavior codings (BCs) of 24 adult males. We found male and female personality constructs to be congruent and examined reliability and construct validity. Combining trait rating and behavioral coding, we found two solutions with five factors to best describe the personality structure of the males: one structure comprised the dimensions Gregariousness BC , Aggressiveness BC , Sociability BC and Vigilance BC , complemented by a Confidence TR domain and the other structure Opportunism TR , Confidence TR , Friendliness TR , Activity TR complemented with Vigiance BC . We discuss our findings with regard to the importance of construct validity and reproducibility in the context of method development and standardization in nonhuman animal personality research.
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Research on links between peoples’ personality traits and their voices has primarily focused on other peoples’ personality judgments about a target person based on a target person’s vocal characteristics, particularly voice pitch. However, it remains unclear whether individual differences in voices are linked to actual individual differences in personality traits, and thus whether vocal characteristics are indeed valid cues to personality. Here, we investigate how the personality traits of the Five Factor Model of Personality, sociosexuality, and dominance are related to measured fundamental frequency (voice pitch) and formant frequencies (formant position). For this purpose, we conducted a secondary data analysis of a large sample (2,217 participants) from eleven different, independent datasets with a Bayesian approach. Results suggest substantial negative relationships between voice pitch and self-reported sociosexuality, dominance and extraversion in men and women. Thus, personality might at least partly be expressed in people’s voice pitch. Evidence for an association between formant frequencies and self-reported personality traits is not compelling but remains uncertain. We discuss potential underlying biological mechanisms of our effects and suggest a number of implications for future research.
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With the advent of online and app-based studies, researchers in psychology are making increasing use of repeated subjective reports. The new methods open up opportunities to study behavior in the field and to map causal processes, but they also pose new challenges. Recent work has added initial elevation bias to the list of common pitfalls; here, higher negative states (i.e., thoughts and feelings) are reported on the first day of assessment than on later days. This article showcases a new approach to addressing this and other measurement reactivity biases. Specifically, we employed a planned missingness design in a daily diary study of more than 1,200 individuals who were assessed over a period of up to 70 days to estimate and adjust for measurement reactivity biases. We found that day of first item presentation, item order, and item number were associated with only negligible bias: items were not answered differently depending on when and where they were shown. Initial elevation bias may thus be more limited than has previously been reported or it may act only at the level of the survey, not at the item level. We encourage researchers to make design choices that will allow them to routinely assess measurement reactivity biases in their studies. Specifically, we advocate the routine randomization of item display and order, as well as of the timing and frequency of measurement. Randomized planned missingness makes it possible to empirically gauge how fatigue, familiarity, and learning interact to bias responses.
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Objectives: The assessment of men’s physical strength is an important part of human social perception, for which observers rely on different kinds of cues. However, besides previous studies being limited in considerable ways, as yet there is no comprehensive investigation of a range of somatometric measures in relation to both objectively measured and observer-perceived physical strength using valid stimuli. Methods: We examined observer-perceptions of physical strength from 3D body scans of N = 165 men, the usage and validity of somatometric measures as cues to strength, differences between strength ratings from stimuli presented on computer monitors versus in real-life size using a projector, and between male and female observers. Results: A medium-sized correlation between measured and perceived strength was found, partly mediated by target men’s chest-to-hip ratio, body density, ankle girth, height, upper arm and forearm girth. No significant differences between men’s and women’s strength perceptions or the method of stimuli presentation (computer monitor vs. projector) emerged. Conclusions: Our findings suggest that men’s physical strength can be assessed with moderate accuracy from 3D body models and that some somatometric measures represent valid cues, which were used by observers, positively predicting both measured and perceived physical strength.
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Few studies have examined birth order effects on personality in countries that are not Western, educated, industrialized, rich, and democratic (WEIRD). However, theories have generally suggested that interculturally universal family dynamics are the mechanism behind birth order effects, and prominent theories such as resource dilution would predict even stronger linear effects in poorer countries. Here, we examine a subset of up to 11 188 participants in the Indonesian Family Life Survey to investigate whether later‐borns differ from earlier‐borns in intelligence, educational attainment, Big Five, and risk aversion. Analyses were performed using within‐family designs in mixed‐effects models. In model comparisons, we tested for linear and non‐linear birth order effects as well as for possible interactions of birth order and sibship size. Our estimated effect sizes are consistent with the emerging account of birth order as having relatively little impact on intelligence, Big Five, and risk aversion. We found a non‐linear pattern for educational attainment that was not robust to imputation of missing data and not aligned with trends in WEIRD countries. Overall, the small birth order effects reported in other studies appear to be culturally specific.
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Mate preferences and mating-related behaviors are hypothesized to change over the menstrual cycle in ways that function to increase reproductive fitness. Results of recent large-scale studies suggest that many of these hormone-linked behavioral changes are less robust than was previously thought. One specific hypothesis that has not yet been subject to a large-scale test is the proposal that women’s preference for associating with male kin is down-regulated during the ovulatory (high-fertility) phase of the menstrual cycle. Consequently, we used a longitudinal design to investigate the relationship between changes in women’s steroid hormone levels and their perceptions of faces experimentally manipulated to possess kinship cues (Study 1). Analyses suggested that women viewed men’s faces displaying kinship cues more positively (i.e., more attractive and trustworthy) when estradiol-to-progesterone ratio was high. Since estradiol-to-progesterone ratio is positively associated with conception risk during the menstrual cycle, these results directly contradict the hypothesis that women’s preference for associating with male kin is down-regulated during the ovulatory (high-fertility) phase of the menstrual cycle. Study 2 employed a daily diary approach and found no evidence that women reported spending less time in the company of male kin or thought about male kin less often during the fertile phase of the menstrual cycle. Thus, neither study found evidence that inbreeding avoidance is up-regulated during the ovulatory phase of the menstrual cycle.