Evolution & Human Behavior RSS feed: Articles in Press. Evolution and Human Behavior is an interdisciplinary journal, presenting research reports and theory in which evolutionary perspectives are brought to bear on the study of human behavior. It is primarily a scientific journal, but submissions from scholars in the humanities are also encouraged. Papers reporting on theoretical and empirical work on other species will be welcome if their relevance to the human animal is apparent. http://www.ehbonline.org//inpress?rss=yesElsevier Inc.en © 2011 Elsevier Inc. All rights reserved. Evolution & Human Behavior1090-51382012-01-27 © 2011 Elsevier Inc. All rights reserved. healthpermissions@elsevier.comhttp://www.ehbonline.org/article/PIIS1090513811001176/abstract?rss=yesAbstract: Prominent evolutionary theories of morality maintain that the adaptations that underlie moral judgment and behavior function, at least in part, to deliver benefits (or prevent harm) to others. These explanations are based on the theories of kin selection and reciprocal altruism, and they predict that moral systems are designed to maximize Hamiltonian inclusive fitness. In sharp contrast, however, moral judgment often appears Kantian and rule-based. To reconcile this apparent discrepancy, some theorists have claimed that Kantian moral rules result from mechanisms that implement simple heuristics for maximizing welfare. To test this idea, we conducted a set of studies in which subjects (N=1290) decided whether they would kill one person to save five others, varying the relationship of the subject with the others involved (strangers, friends, brothers). Are participants more likely to observe the Kantian rule against killing in decisions about brothers and friends, rather than strangers? We found the reverse. Subjects reported greater willingness to kill a brother or friend than a stranger (in order to save five others of the same type). These results suggest that the rule-based structure of moral cognition is not explained by kin selection, reciprocity, or other altruism theories.Hamilton vs. Kant: pitting adaptations for altruism against adaptations for moral judgment - Corrected ProofRobert Kurzban, Peter DeScioli, Daniel Fein10.1016/j.evolhumbehav.2011.11.002Evolution & Human Behavior (2012)2012-01-27Evolution & Human Behavior2012-01-27ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811001103/abstract?rss=yesAbstract: Much attractiveness research has focused on face shape. The role of masculinity (which for adults is thought to be a relatively stable shape cue to developmental testosterone levels) in male facial attractiveness has been examined, with mixed results. Recent work on the perception of skin color (a more variable cue to current health status) indicates that increased skin redness, yellowness, and lightness enhance apparent health. It has been suggested that stable cues such as masculinity may be less important to attractiveness judgments than short-term, more variable health cues. We examined associations between male facial attractiveness, masculinity, and skin color in African and Caucasian populations. Masculinity was not found to be associated with attractiveness in either ethnic group. However, skin color was found to be an important predictor of attractiveness judgments, particularly for own-ethnicity faces. Our results suggest that more plastic health cues, such as skin color, are more important than developmental cues such as masculinity. Further, unfamiliarity with natural skin color variation in other ethnic groups may limit observers' ability to utilize these color cues.Cross-cultural effects of color, but not morphological masculinity, on perceived attractiveness of men's faces - Corrected ProofIan D. Stephen, Isabel M.L. Scott, Vinet Coetzee, Nicholas Pound, David I. Perrett, Ian S. Penton-Voak10.1016/j.evolhumbehav.2011.10.003Evolution & Human Behavior (2012)2012-01-09Evolution & Human Behavior2012-01-09ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811001115/abstract?rss=yesAbstract: Extrapair paternity is a crucial parameter for evolutionary explanations of reproductive behavior. Early studies and human testis size suggest that human males secure/suffer frequent extrapair paternity. If these high rates are indeed true, it brings into question studies that use genealogies to infer human life history and the history of diseases since the recorded genealogies do not reflect paths of genetic inheritance. We measure the rate of nonpaternity in an old Afrikaner family in South Africa by comparing Y-chromosome short tandem repeats to the genealogy of males. In this population, the nonpaternity rate was 0.73%. This low rate is observed in other studies that matched genealogies to genetic markers and more recent studies that also find estimates below 1%. It may be that imposed religious morals have led to reduced extrapair activities in some historic populations. We also found that the mutation rate is high for this family, but is unrelated to age at conception.Low nonpaternity rate in an old Afrikaner family - Corrected ProofJaco M. Greeff, Francois A. Greeff, Andre S. Greeff, Lucas Rinken, Dawid J. Welgemoed, Yolanda Harris10.1016/j.evolhumbehav.2011.10.004Evolution & Human Behavior (2012)2012-01-09Evolution & Human Behavior2012-01-09ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811000997/abstract?rss=yesAbstract: Previous evolutionary literature demonstrating risk taking as a male mating strategy ignored cultural influences and the function of risk avoiding for women. The present research is the first to support the hypothesis that risk taking and risk avoiding, respectively, reflect Chinese male and female mating strategies. In Study 1, when under the impression of being watched by the opposite sex, Chinese men took more risks and women took fewer risks than when watched by a same sex or alone. In Study 2, Chinese male risk taking and female risk avoiding were positively related to their mating-related evaluation of the opposite-sex observer, and these results were reinforced by behavioral findings in Study 3. The implications of the findings regarding Chinese traditional mate preference and the evolutionary mechanism behind it are discussed.Mating strategies in Chinese culture: female risk avoiding vs. male risk taking - Corrected ProofWen Shan, Jin Shenghua, Hunter Morgan Davis, Kaiping Peng, Xiao Shao, Youyou Wu, Shuqing Liu, Jiewen Lu, Jinhua Yang, Weiqing Zhang, Miao Qiao, Jing Wang, Yi Wang10.1016/j.evolhumbehav.2011.09.001Evolution & Human Behavior (2011)2011-12-26Evolution & Human Behavior2011-12-26ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811001000/abstract?rss=yesAbstract: Sexually dimorphic characteristics in men may act as cues, advertising long-term health, dominance, and reproductive potential to prospective mates. Evolution has accordingly adapted human cognition so that women perceive sexually dimorphic facial features as important when judging the attractiveness and suitability of potential mates. Here we provide evidence showing, for the first time, that women's memory for details encountered in recently experienced episodes is also systematically biased by the presence of men's facial cues signaling enhanced or reduced sexual dimorphism. Importantly, the direction and strength of this bias are predicted by individual differences in women's preferences for masculine versus feminine facial features in men and are triggered specifically while viewing images of male but not female faces. No analogous effects were observed in male participants viewing images of feminized and masculinized women's faces despite the fact that male participants showed strong preferences for feminized facial features. These findings reveal a preference-dependent memory enhancement in women that would promote retention of information from encounters with preferred potential mates. We propose that women's memory for recently experienced episodes may therefore be functionally specialized for mate choice and in particular for the comparative evaluation of alternative potential mates. This also raises the possibility that similar specialization may be present in other species where it has been established that precursor, ‘episodic-like’ forms of memory exist.Evidence of adaptation for mate choice within women's memory - Corrected ProofKevin Allan, Benedict C. Jones, Lisa M. DeBruine, David S. Smith10.1016/j.evolhumbehav.2011.09.002Evolution & Human Behavior (2011)2011-12-26Evolution & Human Behavior2011-12-26ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811001012/abstract?rss=yesAbstract: Previous research has posited that facial expressions of emotion may serve as honest signals of cooperation. Although findings from several empirical studies support this position, prior studies have not used comprehensive and dynamic measures of facial expression as potential predictors of behaviorally defined cooperation. The authors investigated (a) specific positive and negative facial actions displayed among strangers immediately following verbal promises of commitment within an unrestricted acquaintance period and (b) anonymous, behaviorally defined decisions of cooperation or defection in a one-shot, two-person Prisoner's Dilemma game occurring directly following the acquaintance period. The Facial Action Coding System [Ekman P. & Friesen W.V. (1978). Facial Action Coding System. Palo Alto, CA: Consulting Psychology Press] was used to measure affect-related facial actions. It was found that facial actions related to enjoyment were predictive of cooperative decisions within dyads; additionally, facial actions related to contempt were predictive of noncooperative decisions within dyads. Furthermore, and consistent with previous works, participants were able to accurately predict their partner's decisions following the acquaintance period. These results suggest that facial actions may function as honest signals of cooperative intent. These findings also provide a possible explanation for the association between subjective affective experience and facial expression that advances understanding of cooperative behavior.Facial expressions as honest signals of cooperative intent in a one-shot anonymous Prisoner's Dilemma game - Corrected ProofLawrence Ian Reed, Katharine N. Zeglen, Karen L. Schmidt10.1016/j.evolhumbehav.2011.09.003Evolution & Human Behavior (2011)2011-12-26Evolution & Human Behavior2011-12-26ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811001036/abstract?rss=yesAbstract: At an ultimate level of explanation, the causes of incest aversion have been linked to the reproductive costs of inbreeding, whereas at a proximate level of explanation, experienced environmental cues relating to the successful recognition of kin have been shown to moderate both the likelihood of engaging in incest and the aversion to descriptions of third-party incest. However, little is known concerning how incest aversion is moderated by evolutionarily relevant factors presented in such descriptions. As disgust has been suggested to down-regulate incestuous sexual interest, we investigated to what extent the gender, biological relatedness, co-residence, and family-relationship type of actors described in incest scenarios moderate the elicited disgust of men and women reading those descriptions. Analyzing responses from 434 participants, we found that women are more disgusted by incest than men, that descriptions of biological incest elicited more disgust than sociolegal incest, that descriptions of incest between family members having co-resided elicited more disgust than incest between family members growing up apart, and that descriptions of incest between a parent and a child elicited more disgust than incest between siblings. Our conclusion is that variations in the degree of disgust elicited by descriptions of third-party incest are consistent with evolutionary hypotheses concerning inbreeding avoidance.Disgust elicited by third-party incest: the roles of biological relatedness, co-residence, and family relationship - Corrected ProofJan Antfolk, Mira Karlsson, Anna Bäckström, Pekka Santtila10.1016/j.evolhumbehav.2011.09.005Evolution & Human Behavior (2011)2011-12-26Evolution & Human Behavior2011-12-26ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811001061/abstract?rss=yesAbstract: The propensity for religious belief and behavior is a universal feature of human societies, but religious practice often imposes substantial costs upon its practitioners. This suggests that during human cultural evolution, the costs associated with religiosity might have been traded off for psychological or social benefits that redounded to fitness on average. One possible benefit of religious belief and behavior, which virtually every world religion extols, is delay of gratification—that is, the ability to forego small rewards available immediately in the interest of obtaining larger rewards that are available only after a time delay. In this study, we found that religious commitment was associated with a tendency to forgo immediate rewards in order to gain larger, future rewards. We also found that this relationship was partially mediated by future time orientation, which is a subjective sense that the future is very close in time and is approaching rapidly. Although the effect sizes of these associations were relatively small in magnitude, they were obtained even when controlling for sex and the Big Five personality traits (Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism).Religious people discount the future less - Corrected ProofEvan C. Carter, Michael E. McCullough, Jungmeen Kim-Spoon, Carolina Corrales, Adam Blake10.1016/j.evolhumbehav.2011.09.006Evolution & Human Behavior (2011)2011-12-26Evolution & Human Behavior2011-12-26ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811001073/abstract?rss=yesAbstract: How communication systems emerge and remain stable is an important question in both cognitive science and evolutionary biology. For communication to arise, not only must individuals cooperate by signaling reliable information, but they must also coordinate and perpetuate signals. Most studies on the emergence of communication in humans typically consider scenarios where individuals implicitly share the same interests. Likewise, most studies on human cooperation consider scenarios where shared conventions of signals and meanings cannot be developed de novo. Here, we combined both approaches with an economic experiment where participants could develop a common language, but under different conditions fostering or hindering cooperation. Participants endeavored to acquire a resource through a learning task in a computer-based environment. After this task, participants had the option to transmit a signal (a color) to a fellow group member, who would subsequently play the same learning task. We varied the way participants competed with each other (either global scale or local scale) and the cost of transmitting a signal (either costly or noncostly) and tracked the way in which signals were used as communication among players. Under global competition, players signaled more often and more consistently, scored higher individual payoffs, and established shared associations of signals and meanings. In addition, costly signals were also more likely to be used under global competition; whereas under local competition, fewer signals were sent and no effective communication system was developed. Our results demonstrate that communication involves both a coordination and a cooperative dilemma and show the importance of studying language evolution under different conditions influencing human cooperation.The establishment of communication systems depends on the scale of competition - Corrected ProofMiguel dos Santos, João F. Matias Rodrigues, Claus Wedekind, Daniel J. Rankin10.1016/j.evolhumbehav.2011.09.007Evolution & Human Behavior (2011)2011-12-26Evolution & Human Behavior2011-12-26ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811001085/abstract?rss=yesAbstract: Traditional criteria for modularity assert that perceptual adaptations for processing evolutionarily important stimuli should operate “automatically” in the sense of requiring no central attentional resources. Here, we test the validity of this automaticity criterion by assessing the attentional demands of a well-studied perceptual adaptation: judgment of facial attractiveness. We used locus-of-slack logic in a dual-task psychological refractory period paradigm, where Task 1 was a speeded judgment of tone pitch (low vs. high), and Task 2 was a speeded judgment of whether a face was attractive or unattractive, with the Task-2 judgment manipulated to have a low or a high difficulty level. In two studies (N=36 and N=73 female participants; 384 trials each), the Task 2 difficulty effects were additive with stimulus-onset asynchronies (100, 300, 500 or 900 ms) on Task 2 response times. According to the locus-of-slack logic, this result implies that participants could not discriminate facial attractiveness level, while their central attentional resources were still occupied by Task 1. If the human capacity for perceiving facial attractiveness—a premier example of an adaptation—does not show automaticity in this sense, automaticity may not be a useful criterion for identifying psychological adaptations.Perception of facial attractiveness requires some attentional resources: implications for the “automaticity” of psychological adaptations - Corrected ProofKyunghun Jung, Eric Ruthruff, Joshua M. Tybur, Nicholas Gaspelin, Geoffrey Miller10.1016/j.evolhumbehav.2011.10.001Evolution & Human Behavior (2011)2011-12-26Evolution & Human Behavior2011-12-26ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811001097/abstract?rss=yesAbstract: Recent mathematical modeling of repeated cultural transmission has shown that the rate at which culture is lost (due to imperfect transmission) will crucially depend on whether individuals receive transmissions from many cultural parents or only from one. However, the modeling assumptions leading up to this conclusion have so far not been empirically assessed. Here we do this for the special case of transmission chains where each individual either receives the same story twice from one cultural parent (and retransmits twice to a cultural child) or receives possibly different versions of the story from two cultural parents (and then retransmits to two cultural children). For this case, we first developed a more general mathematical model of cultural retention that takes into account the possibility of dependence of error rates between transmissions. In this model, under quite plausible assumptions, chains with two cultural parents will have superior retention of culture. This prediction was then tested in two experiments using both written and oral modes of transmission. In both cases, superior retention of culture was found in chains with two cultural parents. Estimation of model parameters indicated that error rates were not identical and independent between transmissions; instead, a primacy effect was suggested, such that the first transmission tends to have higher fidelity than the second transmission.The advantage of multiple cultural parents in the cultural transmission of stories - Corrected ProofKimmo Eriksson, Julie C. Coultas10.1016/j.evolhumbehav.2011.10.002Evolution & Human Behavior (2011)2011-12-26Evolution & Human Behavior2011-12-26ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811000845/abstract?rss=yesAbstract: Theoretical and empirical studies suggest that phenotypic averageness is a sign of an individual's high biological quality. The averageness should therefore be preferred in mates. A condition for such preference is the knowledge of average phenotype in the population. It is envisaged that an individual develops a neural template of typical phenotype on the basis of perceptual experience with images of conspecifics, and the template is then used in attractiveness assessments of potential partners. Regrettably, studies supporting this view are lacking. In the present study, adult male competitive swimmers and men who did not partake in swimming assessed the attractiveness of female silhouettes with proportions typical for swimmers or non-swimmers. Because swimmers see other swimmers relatively frequently, we hypothesize that they prefer swimmer-like female silhouettes more strongly than non-swimmers do. The analysis supports this hypothesis, suggesting that mere visual experience shapes a neural template of a silhouette, which subsequently serves as a reference for attractiveness evaluations.Mere visual experience impacts preference for body shape: evidence from male competitive swimmers - Corrected ProofKrzysztof Kościński10.1016/j.evolhumbehav.2011.08.003Evolution & Human Behavior (2011)2011-12-02Evolution & Human Behavior2011-12-02ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811000833/abstract?rss=yesAbstract: The constituents of attractiveness differ across the sexes. Many relevant traits are dimorphic, suggesting that they are the product of intersexual selection. However, direction of causality is generally difficult to determine, as aesthetic criteria can as readily result from, as cause, dimorphism. Women have proportionately smaller feet than men. Prior work on the role of foot size in attractiveness suggests an asymmetry across the sexes, as small feet enhance female appearance, yet average, rather than large, feet are preferred on men. Previous investigations employed crude stimuli and limited samples. Here, we report on multiple cross-cultural studies designed to overcome these limitations. With the exception of one rural society, we find that small foot size is preferred when judging women, yet no equivalent preference applies to men. Similarly, consonant with the thesis that a preference for youth underlies intersexual selection acting on women, we document an inverse relationship between foot size and perceived age. Examination of preferences regarding, and inferences from, feet viewed in isolation suggests different roles for proportionality and absolute size in judgments of female and male bodies. Although the majority of these results bolster the conclusion that pedal dimorphism is the product of intersexual selection, the picture is complicated by the reversal of the usual preference for small female feet found in one rural society. While possibly explicable in terms of greater emphasis on female economic productivity relative to beauty, the latter finding underscores the importance of employing diverse samples when exploring postulated evolved aesthetic preferences.Testing a postulated case of intersexual selection in humans: The role of foot size in judgments of physical attractiveness and age - Corrected ProofDaniel M.T. Fessler, Stefan Stieger, Salomi S. Asaridou, Umeru Bahia, Mark Cravalho, Philip de Barros, Tiara Delgado, Maryanne L. Fisher, David Frederick, Paulina Geraldo Perez, Cari Goetz, Kevin Haley, Jenée Jackson, Geoff Kushnick, Kevin Lew, Elizabeth Pain, Patrícia Piexinho Florindo, Anne Pisor, Evi Sinaga, Lasma Sinaga, Lisa Smolich, Dong Mei Sun, Martin Voracek10.1016/j.evolhumbehav.2011.08.002Evolution & Human Behavior (2011)2011-11-16Evolution & Human Behavior2011-11-16ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811001024/abstract?rss=yesAbstract: It may be adaptive for voters to recognize good leadership qualities among politicians. Men with lower-pitched voices are found to be more dominant and attractive than are men with higher-pitched voices. Candidate attractiveness and vocal quality relate to voting behavior, but no study has tested the influence of voice pitch on voting-related perceptions. We tested whether voice pitch influenced perceptions of politicians and how these perceptions related to voting behavior. In Study 1, we manipulated voice pitch of recordings of US presidents and asked participants to attribute personality traits to the voices and to choose the voice they preferred to vote for. We found that lower-pitched voices were associated with favorable personality traits more often than were higher-pitched voices and that people preferred to vote for politicians with lower-pitched rather than higher-pitched voices. Furthermore, lower voice pitch was more strongly associated with physical prowess than with integrity in a wartime voting scenario. Thus, sensitivity to vocal cues to dominance was heightened during wartime. In Study 2, we found that participants preferred to vote for the candidate with the lower-pitched voice when given the choice between two unfamiliar men's voices speaking a neutral sentence. Taken together, our results suggest that candidates' voice pitch has an important influence on voting behavior and that men with lower-pitched voices may have an advantage in political elections.Voice pitch influences voting behavior - Corrected ProofCara C. Tigue, Diana J. Borak, Jillian J.M. O'Connor, Charles Schandl, David R. Feinberg10.1016/j.evolhumbehav.2011.09.004Evolution & Human Behavior (2011)2011-11-16Evolution & Human Behavior2011-11-16ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811000699/abstract?rss=yesAbstract: The human face provides a wealth of information pertaining to the internal state and life-stage history of an individual. Facial width-to-height ratio is a size-independent sexually dimorphic trait, and estimates of aggression made by untrained adults judging own-race faces were positively associated with both facial width-to-height ratio and actual aggressive behavior. Given the significant adaptive value of accurately detecting aggressiveness based on facial appearance, we hypothesized that aggression estimates made by adults and 8-year-old children would be highly correlated with male facial width-to-height ratio even for a face category with which they had minimal experience — other-race faces. For each of the four race and age groups, estimates of aggression were positively correlated with facial width-to-height ratio irrespective of rating own- or other-race faces. Overall, the correlations between facial width-to-height ratio and ratings of aggression were stronger for adults than for children. Sensitivity to facial width-to-height ratio appears to be part of an evolved mechanism designed to detect threats in the external environment. This mechanism is likely broadly tuned and functions independently of experience.Detection of propensity for aggression based on facial structure irrespective of face race - Corrected ProofLindsey A. Short, Catherine J. Mondloch, Cheryl M. McCormick, Justin M. Carré, Ruqian Ma, Genyue Fu, Kang Lee10.1016/j.evolhumbehav.2011.07.002Evolution & Human Behavior (2011)2011-11-07Evolution & Human Behavior2011-11-07ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811000821/abstract?rss=yesAbstract: Recently, Weston et al. (2004; Wide faces or large canines? The attractive versus the aggressive primate. Proceedings of the Royal Society of London, Series B, 271, 416–419) found that facial width-to-height ratio (WHR) is a sexually dimorphic characteristic in humans; males have higher facial WHR than females. Following this study, Carré et al. (2008; In your face: facial metrics predict aggressive behavior in the laboratory and in varsity and professional hockey players. Proceedings of the Royal Society of London, Series B, 275, 2651–2656) found that individual differences in facial WHR accounted for a significant proportion of the variance in aggressive behavior of men, but not women. I tested these two hypotheses in a sample of 470 Turkish university students. Facial WHR was measured from frontal photographs. I also measured the aggressiveness level of 212 individuals using the Buss and Perry aggressiveness questionnaire. The mean facial WHR (and standard deviation) was 1.89±0.12 for males and 1.91±0.11 for females. There was no relationship between facial WHR and the self-reported aggressive behavior for either sex. The facial WHR is not a sexually dimorphic characteristic (at least) for Turkish people, and it does not appear to be associated with self-reported trait aggression.Facial width-to-height ratio in a Turkish population is not sexually dimorphic and is unrelated to aggressive behavior - Corrected ProofBarış Özener10.1016/j.evolhumbehav.2011.08.001Evolution & Human Behavior (2011)2011-11-07Evolution & Human Behavior2011-11-07ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811000857/abstract?rss=yesAbstract: The recalibrational theory of human anger predicts positive correlations between aggressive formidability and anger levels in males, and between physical attractiveness and anger levels in females. We tested these predictions by using a three-dimensional body scanner to collect anthropometric data about male aggressive formidability (measures of upper body muscularity and leg–body ratio) and female bodily attractiveness (waist–hip ratio, body mass index, overall body shape femininity, and several other measures). Predictions were partially supported: in males, two of three anger measures correlated significantly positively with several muscularity measures; in females, self-perceived attractiveness correlated significantly positively with two anger measures. However, most of these significant results were observed only after excluding from the sample 27 participants who were older than undergraduate age, leaving a subsample of 40 males and 51 females. Evidence for relationships between anthropometric attractiveness indicators and anger measures was weak, but there was some evidence for relationships between anthropometric attractiveness indicators and self-perceived attractiveness measures. While our results support the recalibrational theory's prediction that anger usage and formidability are positively correlated in males and suggest that this formidability can be assessed via anthropometric measures alone, they also suggest that this prediction may not apply to populations older than undergraduate age. Further, our results suggest that while female anger levels relate positively to self-perceived attractiveness, they are unrelated to most anthropometric measures of bodily attractiveness.Anthropometric correlates of human anger - Corrected ProofMichael E. Price, James Dunn, Sian Hopkins, Jinsheng Kang10.1016/j.evolhumbehav.2011.08.004Evolution & Human Behavior (2011)2011-10-13Evolution & Human Behavior2011-10-13ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811000705/abstract?rss=yesAbstract: The second (index finger) to fourth (ring finger) digit length ratio (2D:4D) is known to be a putative marker of prenatal exposure to testosterone. It has been reported that fetal and adult testosterone may be critical for development of physical and mental traits such as cardiovascular system, reaction time, aggressiveness and masculinity. Testosterone-driven attributes are associated with success in male-to-male physical competition, which may be proxied by ability in sports. Many researchers have found that 2D:4D is sexually dimorphic and is a negative correlate of athletic performance. This study aims to investigate the associations of 2D:4D with measures of power as another possible testosterone-associated trait using ability in sumo wrestling as a proxy for male physical competitiveness. The measures of sumo performance comprised the sumo ranks and winning percentages of 142 Japanese professional sumo wrestlers. We found that sumo wrestlers with low 2D:4D had higher sumo ranks and better winning records. The significant negative associations between 2D:4D and the athletic prowess of sumo wrestlers provide further evidence of the possible link between high testosterone levels and muscle strength. The relatively small effect sizes found in this study, however, imply that 2D:4D may be a weaker predictor for sports requiring explosive power than for those requiring endurance.Second to fourth digit ratio and the sporting success of sumo wrestlers - Corrected ProofRie Tamiya, Sun Youn Lee, Fumio Ohtake10.1016/j.evolhumbehav.2011.07.003Evolution & Human Behavior (2011)2011-10-10Evolution & Human Behavior2011-10-10ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811000675/abstract?rss=yesAbstract: It was recently shown that Austrians associate car front geometry with traits in a way that could be related to face shape geometry mapping to those same overall suites of traits. Yet, possible confounding effects of familiarity with the car models, media coverage and entertainment could not be ruled out. In order to address this, the current study uses a cross-cultural comparison. Adult subjects in two countries (Austria and Ethiopia, n=129) were asked to rate person characteristics of 46 standardized front views of automobiles on various trait scales. These two countries differ substantially with regard to their experience with car models and brands, as well as car marketing and media coverage. Geometric morphometrics was then used to assess the shape information underlying trait attribution. Car shapes for perceived maturity, maleness and dominance were highly similar in both countries, with patterns comparable to shape changes during facial growth in humans: Relative sizes of the forehead and windshield decrease with age/growth, eyes and headlights both become more slit-like, noses and grilles bigger, lips and air-intakes are wider. Austrian participants further attributed various degrees of some interpersonal attitudes and emotions, whereas neither Austrians nor Ethiopians congruently ascribed personalities. Morphological correlates of personal characteristics are discussed, as are person perception and its overgeneralization to inanimate objects. Cross-cultural similarities and differences are addressed, as well as implications for car styling, follow-up studies on driving and pedestrian behavior, and fundamental dimensions in inference from (human) faces.“Cars have their own faces”: cross-cultural ratings of car shapes in biological (stereotypical) terms - Corrected ProofSonja Windhager, Fred L. Bookstein, Karl Grammer, Elisabeth Oberzaucher, Hasen Said, Dennis E. Slice, Truls Thorstensen, Katrin Schaefer10.1016/j.evolhumbehav.2011.06.003Evolution & Human Behavior (2011)2011-09-07Evolution & Human Behavior2011-09-07ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS109051381100064X/abstract?rss=yesAbstract: Handedness is a heritable trait, and left-handedness is related with increased fitness costs. Left-handedness persists, however, as a minority in every human population investigated. One explanation for this persistence has been put forward in the fighting hypothesis, which postulates that left-handers have a frequency-dependent benefit in fights. Support for this has been found in the finding that left-handedness is relatively frequent in populations with high homicide rates, according to estimates of left-handedness partly based on pictures and films made for a different purpose. We measured handedness based on hand preference in 10 ecologically relevant tasks in 621 subjects in the nonindustrial society of the Eipo (Papua, Indonesia) in which homicide rate was very high. This set of tests was validated in 198 Western students. Contrary to the prediction based on the fighting hypothesis, we did not find a high frequency of left-handedness or a difference between men (who participate in warfare) and women (who do not). These findings challenge the idea that fighting is the driving evolutionary force for the persistence of left-handedness in human populations. Furthermore, we found lower percentages of left- and mixed-handers compared to a Western population who executed the same tasks. Since left-handedness is associated with health problems, we suggest that in a society lacking Western health care, selection pressures against left-handedness may be more intense and therefore its frequency may be reduced.Handedness in a nonindustrial society challenges the fighting hypothesis as an evolutionary explanation for left-handedness - Corrected ProofSara M. Schaafsma, Reint H. Geuze, Bernd Riedstra, Wulf Schiefenhövel, Anke Bouma, Ton G.G. Groothuis10.1016/j.evolhumbehav.2011.06.001Evolution & Human Behavior (2011)2011-08-22Evolution & Human Behavior2011-08-22ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811000651/abstract?rss=yesAbstract: Most social science research portrays attitudes and behaviors as a product of one's environment or social upbringing. Recently, however, scholars have begun to expand upon this paradigm by showing that biological factors such as genes, which are passed from parents to offspring, can also help explain differences in political attitudes and behaviors. As a result, illuminating how spouses select one another is the first step toward understanding both the genetic and social transmission of political preferences from parents to offspring. Yet the question of whether individuals actively seek out mates who are more politically similar is unknown. To address this lacuna, data were gathered from Internet dating profiles. These data show that most individuals are reluctant to advertise politics when attempting to attract a mate. However, the correlates of political attitudes and behavior, such as education and civic engagement, do predict whether a person uses politics as a way to attract a mate. Thus, although spouses share such predilections more than almost any other trait, individuals do not appear to initially select potential dates along political lines.Do bedroom eyes wear political glasses? The role of politics in human mate attraction - Corrected ProofCasey A. Klofstad, Rose McDermott, Peter K. Hatemi10.1016/j.evolhumbehav.2011.06.002Evolution & Human Behavior (2011)2011-08-22Evolution & Human Behavior2011-08-22ORIGINAL ARTICLEhttp://www.ehbonline.org/article/PIIS1090513811000614/abstract?rss=yesAbstract: Using realistic three-dimensional female body models, we found evidence for a categorical perception of female physical attractiveness and health in male and female Caucasian observers. In a rating task, we showed that these bodies were rated for attractiveness or health in the same way as real bodies. In a two-alternative forced-choice task, we showed that these bodies were categorized into attractive vs. unattractive or healthy vs. unhealthy nonlinearly, which allowed us to estimate the position of a categorical boundary between attractive and unattractive or healthy and unhealthy bodies. In a delayed match-to-sample task, we measured the sensitivity of discrimination between pairs of bodies. We found significantly better discrimination for pairs that crossed the attractive/unattractive or healthy/unhealthy boundary than pairs that did not, even though the physical changes in both conditions were identical. Thus, categorical perception enhances the perception of physical changes that cross the boundary between discrete perceptual categories of important judgments such as attractiveness or health, which can be a cue for mate selection.Categorical perception of human female physical attractiveness and health - Corrected ProofMartin J. Tovée, Laura Edmonds, Quoc C. Vuong10.1016/j.evolhumbehav.2011.05.008Evolution & Human Behavior (2011)2011-08-17Evolution & Human Behavior2011-08-17ORIGINAL ARTICLE