bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-Perceived Attractiveness, Romantic Desirability and Self-Esteem: A Mating Sociometer Perspective
Authors: Bale Christopher , Archer John
Published: July 2015

Sociometer theory proposes that self-esteem is an adaptation which evolved to monitor and regulate interpersonal relationships. It is therefore sensitive to self-assessments in domains relevant to relational desirability. Positive relationships between self-perceived physical attractiveness and self-esteem found in previous studies may reflect the functioning of a mating sociometer, designed to monitor individuals' desirability as romantic or sexual partners. We thus predicted that these relationships should be mediated by self-perceptions of romantic desirability, or more specifically, individuals' confidence in their abilities to successfully establish and maintain romantic relationships. Two hundred and eighty seven young adults (98 male) completed an online measure of self-perceived attractiveness, together with measures of self-confidence in appearance and romantic relationships, body-esteem and global self-esteem. Linear regression analyses indicated that self-perceived attractiveness, self-confidence in appearance and body-esteem all significantly predicted self-esteem, and that in each case, the relationship was mediated by romantic self-confidence. Self-perceived attractiveness predicted self-esteem significantly more strongly in females than in males. We discuss these results in relation to sociometer and parental investment theories, and explore limitations and future directions.
Laughing at the Looking Glass: Does Humor Style Serve as an Interpersonal Signal?
Authors: Zeigler-Hill Virgil , Besser Avi , Jett Stephanie E.
Published: July 2015

Objective: The provision of information appears to be an important feature of humor. The present studies examined whether humor serves as an interpersonal signal such that an individual's style of humor is associated with how the individual is perceived by others. Method: We examined this issue across two studies. In Study 1, undergraduate participants (257 targets) were rated more positively by their friends and family members (1194 perceivers) when they possessed more benign humor styles. In Study 2, 1190 community participants rated the romantic desirability of targets ostensibly possessing different humor styles. Results: Across both studies, our results were consistent with the possibility that humor serves as a signal. More specifically, individuals with benign humor styles (affiliative and self-enhancing humor styles) were evaluated more positively than those targets with injurious humor styles (aggressive and self-defeating humor styles). Conclusion: These findings are discussed in terms of the role that humor may play in interpersonal perception and relationships.
Rape Avoidance Behavior among Slovak Women
Authors: Prokop Pavol
Published: July 2015

Rape has been a recurrent adaptive problem for many species, including humans. Rape is costly to women in terms of disease transmission, partner abandonment, and unwanted pregnancy (among other costs). Therefore, behavioral strategies which allow women to avoid coercive men may have been favored by selection. In line with this evolutionary reasoning, the current research documented that physically stronger women and those in a committed romantic relationship reported more rape avoidance behavior. In addition, virgin women tended to perform more rape avoidance behavior compared with their non-virgin counterparts. Women with high conception risk perceived themselves as physically stronger, which may protect them against a potential rapist. Fear of unwanted pregnancy from rape decreased as age increased, reflecting higher fertility among younger participants. However, older women reported more rape avoidance behavior, which contradicts evolutionary predictions. The results provide some support for evolutionary hypotheses of rape avoidance behavior which suggest that woman's perception of rape is influenced by parental investment and perceived physical condition.
Is Cunnilingus-Assisted Orgasm a Male Sperm-Retention Strategy?
Authors: Pham Michael N. , Shackelford Todd K. , Sela Yael , Welling Lisa L. M.
Published: July 2015

We secured data from 243 men in committed, sexual, heterosexual relationships to test the sperm retention hypothesis of oral sex. We predicted that, among men who perform cunnilingus on their partner, those at greater risk of sperm competition are more likely to perform cunnilingus until their partner achieves orgasm (Prediction 1), and that, among men who ejaculate during penile-vaginal intercourse and whose partner experiences a cunnilingus-assisted orgasm, ejaculation will occur during the brief period in which female orgasm might function to retain sperm (Prediction 2). The results support Prediction 1 but not Prediction 2. We discuss limitations of the current research and discuss how these results may be more consistent with alternative hypotheses regarding female orgasm and oral sex.
The Association between Grandmaternal Investment and Early Years Overweight in the UK
Authors: Tanskanen Antti O.
Published: July 2015

Previous studies show that in many pre-modern and traditional populations the presence of a grandmother correlates with increased child survival rates, maybe as a result of improved child nutrition. Grandmaternal investment aimed at improving grandchildren's nutritional status in subsistence societies may have different outcomes in contemporary affluent societies. Using the British Millennium Cohort Study I investigate the association between maternal and paternal grandmothers' childcare and early years overweight in the UK. Results show that children who were cared for mainly by their grandmothers between the ages of 9 months and 3 years were more likely overweight at age 3 than children who were cared for by their parents. My results are in line with Pearce, Abbas, Ferguson, Graham, and Law (2010) , although they did not distinguish grandmothers by lineage. Grandmothers may influence children's nutritional status in contemporary societies, but as with many evolved behavioral strategies the outcome may be no longer beneficial.
Why Offspring in Nonhuman Families Differ
Authors: Forbes Scott
Published: July 2015

Offspring within families, both human and nonhuman, often differ. The obvious question is: Why? Work on psychological differences on children within human families has focused primarily on differences in the nonshared environment of contemporary siblings, though the precise location of this nonshared environment is still the subject of much debate. Here I explore the range of explanations for within-brood diversity from the perspective of nonhuman families, particularly birds that share certain key features with human families. I examine the role of social rank in creating a nonshared environment within the family, and present data from a model system (an altricial bird) to illustrate how different the effective environments experienced by offspring sitting side-by-side in the same confined physical space, tended by the same parents, and experiencing similar ecological variability, can be. These broodmates can effectively live in different worlds. I then briefly explore other sources of diversity among offspring in nonhuman families, including within brood genetic differences and non-genetic maternal (parental) effects that often covary with birth / hatching rank. Given the ubiquity and far-reaching consequences of maternal effects in nonhuman families, and some human data suggestive of similar patterns, it would seem worthwhile to explore the potential role of maternal effects in creating phenotypic diversity in psychological traits among children in human families.
Comparative Approaches to Studying Strategy: Towards an Evolutionary Account of Primate Decision Making
Authors: Brosnan Sarah F. , Beran Michael J. , Parrish Audrey E. , Price Sara A. , Wilson Bart J.
Published: July 2015

How do primates, humans included, deal with novel problems that arise in interactions with other group members? Despite much research regarding how animals and humans solve social problems, few studies have utilized comparable procedures, outcomes, or measures across different species. Thus, it is difficult to piece together the evolution of decision making, including the roots from which human economic decision making emerged. Recently, a comparative body of decision making research has emerged, relying largely on the methodology of experimental economics in order to address these questions in a cross-species fashion. Experimental economics is an ideal method of inquiry for this approach. It is a well-developed method for distilling complex decision making involving multiple conspecifics whose decisions are contingent upon one another into a series of simple decision choices. This allows these decisions to be compared across species and contexts. In particular, our group has used this approach to investigate coordination in New World monkeys, Old World monkeys, and great apes (including humans), using identical methods. We find that in some cases there are remarkable continuities of outcome, as when some pairs in all species solved a coordination game, the Assurance game. On the other hand, we also find that these similarities in outcomes are likely driven by differences in underlying cognitive mechanisms. New World monkeys required exogenous information about their partners' choices in order to solve the task, indicating that they were using a matching strategy. Old World monkeys, on the other hand, solved the task without exogenous cues, leading to investigations into what mechanisms may be underpinning their responses (e.g., reward maximization, strategy formation, etc.). Great apes showed a strong experience effect, with cognitively enriched apes following what appears to be a strategy. Finally, humans were able to solve the task with or without exogenous cues. However, when given the chance to do so, they incorporated an additional mechanism unavailable to the other primates - language - to coordinate outcomes with their partner. We discuss how these results inform not only comparative psychology, but also evolutionary psychology, as they provide an understanding of the evolution of human economic behavior, and the evolution of decision making more broadly.
Are Clark's Nutcrackers (Nucifraga Columbiana) Able to Discriminate Knowledge States of Human Experimenters during an Object-Choice Task?
Authors: Clary Dawson , Kelly Debbie M.
Published: July 2015

Corvids and primates have been shown to possess similar cognitive adaptations, yet these animals are seldom tested using similar procedures. Object-choice tasks, which have commonly been used to test whether an animal is able to infer the mental state of a human experimenter based on a gestural cue, provide one potential means of testing these animals using a similar paradigm. The current study used an object-choice task to examine whether the corvid, Clark's nutcracker ( Nucifraga columbiana), is able to use a cognitive strategy to discriminate between the knowledge states of two human experimenters. One experimenter was informed, and the other uninformed, as to the location of a food reward hidden inside one of two opaque containers. During the Uninformed Gesture condition, the nutcrackers were given probe tests during which only the person performing as the uninformed experimenter provided a gesture. Thus, the nutcrackers could not use the experimenter's gesture to reliably find the food. During the Gesture Conflict condition, the nutcrackers were presented with a cue conflict. During probe tests, both the informed and the uninformed experimenter gestured to separate containers. Thus, to find the food the nutcrackers had to use the gesture from the informed experimenter and refrain from using the gesture of the uninformed experimenter. Our results showed that when the uninformed experimenter's gesture was presented alone, the birds continued to follow the gesture even though it was not consistently predictive of the food's location. However, when provided with two conflicting gestures, as a group the nutcrackers responded to the gesture of the informed experimenter at above chance levels. These results suggest that the birds had learned that the gesture was informative, perhaps by associative learning, yet when this mechanism was not reliable the nutcrackers were able to use either the human experimenters' presence/absence during the baiting process, or possibly their knowledge states, to determine which gesture to rely upon.
Do as We Wish: Parental Tactics of Mate Choice Manipulation
Authors: Apostolou Menelaos
Published: July 2015

The mate choices of children do not always meet with the approval of their parents. As a consequence, the latter employ a battery of tactics that they use to manipulate the mating behavior of the former. This paper offers the first taxonomy of parental tactics of mate choice manipulation. In particular, in Study 1, 57 semi-structured interviews revealed 72 acts that parents employ to influence their children, and 27 that they employ to influence their children's partners. In Study 2, 405 parents rated how likely they were to use these acts to influence their daughters' and sons' mate choices. Factor analysis of participants' responses revealed 12 manipulation tactics that parents use on their children, and four manipulation tactics that they use on their children's partners.
Is There an Own-Race Preference in Attractiveness?
Authors: Burke Darren , Nolan Caroline , Hayward William Gordon , Russell Robert , Sulikowski Danielle
Published: July 2015

Even in multicultural nations interracial relationships and marriages are quite rare, one reflection of assortative mating. A relatively unexplored factor that could explain part of this effect is that people may find members of their own racial group more attractive than members of other groups. We tested whether there is an own-race preference in attractiveness judgments, and also examined the effect of familiarity by comparing the attractiveness ratings given by participants of different ancestral and geographic origins to faces of European, East Asian and African origin. We did not find a strong own-race bias in attractiveness judgments, but neither were the data consistent with familiarity, suggesting an important role for other factors determining the patterns of assortative mating observed.
Binocular Symmetry/Asymmetry of Scleral Redness as a Cue for Sadness, Healthiness, and Attractiveness in Humans
Authors: Provine Robert R. , Cabrera Marcello O. , Nave-Blodgett Jessica
Published: July 2015

Among primates, only humans have the white sclerae that provide the ground necessary to display their own color and that of the overlying conjunctiva. Scleral color, primarily redness, provides cues of socially and biologically significant information about an individual. The present study examines the effect of the asymmetry of binocular scleral redness on perceived sadness, healthiness, and attractiveness by contrasting ratings of images of individuals who had one, both, or neither sclera reddened by digital editing. Building upon previous research, this study further defines the details of the scleral color display and contributes to the more general issue of facial and body symmetry, predictors of phenotypic condition and genotypic quality that are of interest to evolutionary theorists. Individuals with binocular and monocular redness were rated as sadder, less healthy, and less attractive than those with untinted control sclerae, with ratings corresponding to the degree of redness or whiteness. Bilaterally symmetrical (binocular) scleral redness or whiteness provided anchorage points for ratings, with ratings for bilaterally asymmetrical (monocular) redness or whiteness falling between them; there was no unique effect of asymmetry.
Is Beauty in the Eye of the Beholder but Ugliness Culturally Universal? Facial Preferences of Polish and Yali (Papua) People
Authors: Sorokowski Piotr , Kościński Krzysztof , Sorokowska Agnieszka
Published: July 2015

Previous studies suggest that human facial attractiveness is culturally universal. As they were conducted among Western populations and populations strongly influenced by the Western culture, it is not obvious if the preferences would also be the same in populations isolated from this culture. It is also not certain if the agreement would be the same in the case of attractive and unattractive faces. In the presented study participated 103 people from the Yali tribe (Papua, Indonesia) and 99 Poles. Their task was to choose the most attractive and unattractive face of the opposite sex from a set of 4 pictures (one attractive, one unattractive and two average faces of Polish people chosen in a pre-test). We showed significant cross-cultural differences in attractiveness preferences and similarities in choices of unattractive faces. We speculate that across cultures unattractiveness could be assessed on the basis of the same cues to health and biological quality. Attractiveness criteria seem to be more complex, specific to each population, and dependent on the population's ecological conditions and morphological characteristics.
Digit Ratio (2D:4D), Aggression, and Testosterone in Men Exposed to an Aggressive Video Stimulus
Authors: Kilduff Liam P. , Hopp Renato N. , Cook Christian J. , Crewther Blair T. , Manning John T.
Published: July 2015

The relative lengths of the 2nd and 4th digits (2D:4D) is a negative biomarker for prenatal testosterone, and low 2D:4D may be associated with aggression. However, the evidence for a 2D:4D-aggression association is mixed. Here we test the hypothesis that 2D:4D is robustly linked to aggression in “challenge” situations in which testosterone is increased. Participants were exposed to an aggressive video and a control video. Aggression was measured after each video and salivary free testosterone levels before and after each video. Compared to the control video, the aggressive video was associated with raised aggression responses and a marginally significant increase in testosterone. Left 2D:4D was negatively correlated with aggression after the aggressive video and the strength of the correlation was higher in those participants who showed the greatest increases in testosterone. Left 2D:4D was also negatively correlated to the difference between aggression scores in the aggressive and control conditions. The control video did not influence testosterone concentrations and there were no associations between 2D:4D and aggression. We conclude that 2D:4D moderates the impact of an aggressive stimulus on aggression, such that an increase in testosterone resulting from a “challenge” is associated with a negative correlation between 2D:4D and aggression.
Changes in Women's Attractiveness Perception of Masculine Men's Dances across the Ovulatory Cycle: Preliminary Data
Authors: Cappelle Tessa , Fink Bernhard
Published: July 2015

Women's preferences for putative cues of genetic quality in men's voices, faces, bodies, and behavioral displays are stronger during the fertile phase of the ovulatory cycle. Here we show that ovulatory cycle-related changes in women's attractiveness perceptions of male features are also found with dance movements, especially those perceived as highly masculine. Dance movements of 79 British men were recorded with an optical motion-capture system whilst dancing to a basic rhythm. Virtual humanoid characters (avatars) were created and converted into 15-second video clips and rated by 37 women on masculinity. Another 23 women judged the attractiveness of the 10 dancers who scored highest and those 10 who scored lowest on masculinity once in days of high fertility and once in days of low fertility of their ovulatory cycle. High-masculine dancers were judged higher on attractiveness around ovulation than on other cycle days, whilst no such perceptual difference was found for low-masculine dancers. We suggest that women may gain fitness benefits from evolved preferences for masculinity cues they obtain from male dance movements.
Evolutionary Relevance Facilitates Visual Information Processing
Authors: Jackson Russell E. , Calvillo Dustin P.
Published: July 2015

Visual search of the environment is a fundamental human behavior that perceptual load affects powerfully. Previously investigated means for overcoming the inhibitions of high perceptual load, however, generalize poorly to real-world human behavior. We hypothesized that humans would process evolutionarily relevant stimuli more efficiently than evolutionarily novel stimuli, and evolutionary relevance would mitigate the repercussions of high perceptual load during visual search. Animacy is a significant component to evolutionary relevance of visual stimuli because perceiving animate entities is time-sensitive in ways that pose significant evolutionary consequences. Participants completing a visual search task located evolutionarily relevant and animate objects fastest and with the least impact of high perceptual load. Evolutionarily novel and inanimate objects were located slowest and with the highest impact of perceptual load. Evolutionary relevance may importantly affect everyday visual information processing.
Taking Control of Aggression: Perceptions of Aggression Suppress the Link between Perceptions of Facial Masculinity and Attractiveness
Authors: Geniole Shawn N. , McCormick Cheryl M.
Published: July 2015

Women's preferences for masculine-looking male faces are inconsistent across studies, with some studies finding a positive relationship between masculinity and attractiveness and others finding a negative relationship or no association. One possible reason for this inconsistency is that the perception of masculinity is also associated with perceptions of aggression, which may be viewed as particularly costly to women (aggressive individuals are more likely to experience injury or death). Based on the proposal that women's preference for masculinity is in conflict with their aversion for aggression in male faces, we hypothesized that the bivariate associations between perceptions of masculinity and attractiveness would be weak or negative, but would be positive and significantly stronger after controlling statistically for perceptions of aggression. Across three studies involving three sets of faces ( n = 25, 54, 24) and five sets of raters ( n = 29, 30, 26, 16, 10), this hypothesis was supported with the average correlation between perceptions of masculinity and attractiveness ( r = −.09) reversing in direction and substantially increasing in magnitude after perceptions of aggression were controlled statistically ( r = .35). Perceived masculinity may thus involve both attractive and unattractive components, and women's preferences for masculinity may involve weighing its relative costs and benefits.
Judgments of Dominance from the Face Track Physical Strength
Authors: Toscano Hugo , Schubert Thomas W. , Sell Aaron N.
Published: July 2015

It is commonly assumed that judgments of dominance from faces partly rely on implicit judgments of bodily strength. In two studies, we demonstrate such a relation for both computer-generated and natural photos of male faces. We find support when aggregating data across participants, when analyzing with hierarchical models, and also when strength and dominance are judged by different raters. Moreover, we identify common predictors that underlie perceptions of both strength and dominance: brow height, eye length, chin length, and the widths of the nose and mouth.
Gaze Properties of Women Judging the Attractiveness of Masculine and Feminine Male Faces
Authors: Burriss Robert P. , Marcinkowska Urszula M. , Lyons Minna T.
Published: July 2015

Most studies of female facial masculinity preference have relied upon self-reported preference, with participants selecting or rating the attractiveness of faces that differ in masculinity. However, researchers have not established a consensus as to whether women's general preference is for male faces that are masculine or feminine, and several studies have indicated that women prefer neither. We investigated women's preferences for male facial masculinity using standard two-alternative forced choice (2AFC) preference trials, paired with eye tracking measures, to determine whether conscious and non-conscious measures of preference yield similar results. We found that women expressed a preference for, gazed longer at, and fixated more frequently on feminized male faces. We also found effects of relationship status, relationship context (whether faced are judged for attractiveness as a long- or short-term partner), and hormonal contraceptive use. These results support previous findings that women express a preference for feminized over masculinized male faces, demonstrate that non-conscious measures of preference for this trait echo consciously expressed preferences, and suggest that certain aspects of the preference decision-making process may be better captured by eye tracking than by 2AFC preference trials.
Current Hormonal Contraceptive Use Predicts Female Extra-Pair and Dyadic Sexual Behavior: Evidence Based on Czech National Survey Data
Authors: Klapilová Kateřina , Cobey Kelly D. , Wells Timothy , Roberts S. Craig , Weiss Petr , Havlíček Jan
Published: July 2015

Data from 1155 Czech women (493 using oral contraception, 662 non-users), obtained from the Czech National Survey of Sexual Behavior, were used to investigate evolutionary-based hypotheses concerning the predictive value of current oral contraceptive (OC) use on extra-pair and dyadic (in-pair) sexual behavior of coupled women. Specifically, the aim was to determine whether current OC use was associated with lower extra-pair and higher in-pair sexual interest and behavior, because OC use suppresses cyclical shifts in mating psychology that occur in normally cycling women. Zero-inflated Poisson (ZIP) regression and negative binomial models were used to test associations between OC use and these sexual measures, controlling for other relevant predictors (e.g., age, parity, in-pair sexual satisfaction, relationship length). The overall incidence of having had an extra-pair partner or one-night stand in the previous year was not related to current OC use (the majority of the sample had not). However, among the women who had engaged in extra-pair sexual behavior, OC users had fewer one-night stands than non-users, and tended to have fewer partners, than non-users. OC users also had more frequent dyadic intercourse than non-users, potentially indicating higher commitment to their current relationship. These results suggest that suppression of fertility through OC use may alter important aspects of female sexual behavior, with potential implications for relationship functioning and stability.
Parental Choice: Exploring in-Law Preferences and Their Contingencies in the Greek-Cypriot Culture
Authors: Apostolou Menelaos
Published: July 2015

Despite the fact that parents exercise considerable influence over their children's choice of a mate, little is known of their preferences for daughters- and sons-in-law, particularly in a post-industrial context. This research aims to close the gap in our knowledge by making a taxonomic contribution on the qualities desired in an in-law. In particular, parents have rated the desirability of 88 traits in a prospective daughter-in-law and a son-in-law; using principal components analysis, these traits have been classified into 11 broader in-law preferences. On the basis of this classification, four hypotheses were tested: First, parents ascribe different weights to different traits; second, parental preferences are contingent upon the sex of the in-law (i.e., certain traits are valued differently in a son- and in a daughter-in-law); third, parents have a preference for assortative mating (i.e., they want their prospective in-laws and their families to be similar to them); and fourth, in-law preferences are independent of the sex of the parent (i.e., mothers and fathers are in agreement with respect to what qualities they seek in a spouse for their children). The results from two independent studies provide support for the first three hypotheses, but little support for the fourth hypothesis.
Psychometrics and Life History Strategy: The Structure and Validity of the High K Strategy Scale
Authors: Copping Lee T. , Campbell Anne , Muncer Steven
Published: July 2015

In this paper, we critically review the conceptualization and implementation of psychological measures of life history strategy associated with Differential K theory. The High K Strategy Scale (HKSS: Giosan, 2006 ) was distributed to a large British sample ( n = 809) with the aim of assessing its factor structure and construct validity in relation to theoretically relevant life history variables: age of puberty, age of first sexual encounter, and number of sexual partners. Exploratory and confirmatory factor analyses indicated that the HKSS in its current form did not show an adequate statistical fit to the data. Modifications to improve fit indicated four correlated factors (personal capital, environmental stability, environmental security, and social capital). Later puberty in women was positively associated with measures of the environment and personal capital. Among men, contrary to Differential K predictions but in line with female mate preferences, earlier sexual debut and more sexual partners were positively associated with more favorable environments and higher personal and social capital. We raise concerns about the use of psychometric indicators of lifestyle and personality as proxies for life history strategy when they have not been validated against objective measures derived from contemporary life history theory and when their status as causes, mediators, or correlates has not been investigated.
An Introduction to Evolutionary Developmental Psychology
Authors: Machluf Karin , Liddle James R. , Bjorklund David F.
Published: July 2015

Evolutionary developmental psychology represents a synthesis of modern evolutionary theory and developmental psychology. Here we introduce the special issue on evolutionary developmental psychology by briefly discussing the history of this field and then summarizing the variety of topics that are covered. In this special issue, leading researchers provide a collection of theoretical and empirical articles that highlight recent findings and propose promising areas for future research.
Social Defense: An Evolutionary-Developmental Model of Children's Strategies for Coping with Threat in the Peer Group
Authors: Martin Meredith J. , Davies Patrick T. , MacNeill Leigha A.
Published: July 2015

Navigating the ubiquitous conflict, competition, and complex group dynamics of the peer group is a pivotal developmental task of childhood. Difficulty negotiating these challenges represents a substantial source of risk for psychopathology. Evolutionary developmental psychology offers a unique perspective with the potential to reorganize the way we think about the role of peer relationships in shaping how children cope with the everyday challenges of establishing a social niche. To address this gap, we utilize the ethological reformulation of the emotional security theory as a guide to developing an evolutionary framework for advancing an understanding of the defense strategies children use to manage antagonistic peer relationships and protect themselves from interpersonal threat ( Davies and Sturge-Apple, 2007 ). In this way, we hope to illustrate the value of an evolutionary developmental lens in generating unique theoretical insight and novel research directions into the role of peer relationships in the development of psychopathology.
An Evolutionary Model of the Environmental Conditions that Shape the Development of Prosociality
Authors: O'Brien Daniel Tumminelli
Published: July 2015

The current review presents a model for how prosocial development is driven by sociocognitive mechanisms that have been shaped by natural selection to translate critical environmental factors into locally adaptive levels of prosociality. This is done through a synthesis of two existing literatures. Evolutionary developmental psychologists have demonstrated a biological basis for the emergence of prosocial behavior early in youth, and work based on social learning theory has explored how social experiences can influence prosociality across development. The model forwarded organizes this latter literature in a way that is specific to how the biological mechanisms underpinning prosociality have evolved. This consists of two main psychological mechanisms. 1) A domain-specific program that is responsive to environmental factors that determine the relative success of different levels of prosociality. It uses the local prevalence of prosocial others (i.e., support) and expectations for prosocial behavior (i.e., structure) to guide prosocial development. 2) The domain-general process of cultural learning, by which youth adopt local social norms based on the examples of others. Implications and hypotheses are articulated for both the sociocognitive structure of the individual and the role of social contexts.
Does Playing Pay? The Fitness-Effect of Free Play during Childhood
Authors: Greve Werner , Thomsen Tamara , Dehio Cornelia
Published: July 2015

Evolutionary developmental psychology claims that the sequences and processes of human development, in fact the mere fact of ontogeny itself, have to be viewed as evolutionary products. However, although the functional benefits of childish behavior (child playing) for cognitive and emotional development have been shown repeatedly, claiming evolutionary adaptiveness of playing in childhood suggests that childish play supports evolutionary success in mature stages of development. This hypothesis is tested in a study with N = 134 adults (93 females; age range 20–66 years). Participants were asked to recollect their play experiences during childhood in detail, and to report their current developmental status with respect to several aspects of social success. Results show that the opportunity for and the promotion of free play in childhood significantly predict some indicators of social success. Additional analyses strive to explore mediating processes for this relationship. In particular, the mediating role of individual adaptivity (flexibility of goal adjustment) is investigated. Results suggest that freely playing in childhood promotes developmental resources, in particular individual adaptivity in adulthood, which, in turn, promote developmental success.
Misrepresentations of Evolutionary Psychology in Sex and Gender Textbooks
Authors: Winegard Benjamin M. , Winegard Bo M. , Deaner Robert O.
Published: July 2015

Evolutionary psychology has provoked controversy, especially when applied to human sex differences. We hypothesize that this is partly due to misunderstandings of evolutionary psychology that are perpetuated by undergraduate sex and gender textbooks. As an initial test of this hypothesis, we develop a catalog of eight types of errors and document their occurrence in 15 widely used sex and gender textbooks. Consistent with our hypothesis, of the 12 textbooks that discussed evolutionary psychology, all contained at least one error, and the median number of errors was five. The most common types of errors were “Straw Man,” “Biological Determinism,” and “Species Selection.” We conclude by suggesting improvements to undergraduate sex and gender textbooks.
Art as an Indicator of Male Fitness: Does Prenatal Testosterone Influence Artistic Ability?
Authors: Crocchiola Danae
Published: July 2015

In his groundbreaking research, Geoffrey Miller (1999) suggests that artistic and creative displays are male-predominant behaviors and can be considered to be the result of an evolutionary advantage. The outcomes of several surveys conducted on jazz and rock musicians, contemporary painters, English writers ( Miller, 1999 ), and scientists ( Kanazawa, 2000 ) seem to be consistent with the Millerian hypothesis, showing a predominance of men carrying out these activities, with an output peak corresponding to the most fertile male period and a progressive decline in late maturity. One way to evaluate the sex-related hypothesis of artistic and cultural displays, considered as sexual indicators of male fitness, is to focus on sexually dimorphic traits. One of them, within our species, is the 2nd to 4th digit length (2D:4D), which is a marker for prenatal testosterone levels. This study combines the Millerian theories on sexual dimorphism in cultural displays with the digit ratio, using it as an indicator of androgen exposure in utero. If androgenic levels are positively correlated with artistic exhibition, both female and male artists should show low 2D:4D ratios. In this experiment we tested the association between 2D:4D and artistic ability by comparing the digit ratios of 50 artists (25 men and 25 women) to the digit ratios of 50 non-artists (25 men and 25 women). Both male and female artists had significantly lower 2D:4D ratios (indicating high testosterone) than male and female controls. These results support the hypothesis that art may represent a sexually selected, typically masculine behavior that advertises the carrier's good genes within a courtship context.
Covert Sexual Signaling: Human Flirtation and Implications for other Social Species
Authors: Gersick Andrew , Kurzban Robert
Published: July 2015

According to signaling theory and a large body of supporting evidence, males across many taxa produce courtship signals that honestly advertise their quality. The cost of producing or performing these signals maintains signal honesty, such that females are typically able to choose the best males by selecting those that produce the loudest, brightest, longest, or otherwise highest-intensity signals, using signal strength as a measure of quality. Set against this background, human flirting behavior, characterized by its frequent subtlety or covertness, is mysterious. Here we propose that the explanation for subtle and ambiguous signals in human courtship lies in socially imposed costs that (a) vary with social context and (b) are amplified by the unusual ways in which language makes all interactions potentially public. Flirting is a class of courtship signaling that conveys the signaler's intentions and desirability to the intended receiver while minimizing the costs that would accompany an overt courtship attempt. This proposal explains humans' taxonomically unusual courtship displays and generates a number of novel predictions for both humans and non-human social animals. Individuals who are courting should vary the intensity of their signals to suit the level of risk attached to the particular social configuration, and receivers may assess this flexible matching of signal to context as an indicator of the signaler's broader behavioral flexibility and social intelligence.
The Self-Regulation Effect of Fertility Status on Inbreeding Aversion: When Fertile, Disgust Increases more in Response to Descriptions of One's Own than of Others' Inbreeding
Authors: Antfolk Jan , Lieberman Debra , Albrecht Anna , Santtila Pekka
Published: July 2015

The ovulatory shift modulates emotions related to female sexuality. Because fertility status only affects the individual's own opportunity cost, the adaptive value of this shift is expected to stem from self-regulation. To test this assumption we asked women to contemplate various inbreeding descriptions: 1) they themselves having sex with male relatives; 2) their sister having sex with their common male relatives; and 3) an unrelated woman having sex with her male relatives (in 1, but not 2 and 3, negative fitness consequences are affected by the participant's fertility). We dichotomized the dependent variable disgust (ceiling vs. non-ceiling) and analyzed the interaction between fertility status and description type. The ovulatory shift was stronger in descriptions where they themselves were described as engaging in inbreeding. A smaller increase was also found in reactions to others engaging in inbreeding. We explain the latter effect as due to self-reflection.
Infidelity and Kin Selection: Does Cheating Seem as Bad when it's “All in the Family”?
Authors: Kostic Bogdan , Yadon Carly A.
Published: July 2015

The current study explored people's perceptions of how they would feel if their partners cheated on them by having sex with their relatives, such as if a man's wife had sex with his brother. Kin selection theory suggests that in such situations, victims of infidelity might feel slightly better if their partners had sex with biological relatives (compared to sex with nonrelatives) because some of the victims' genes could still get passed on through their relatives. In two experiments, participants reported how they would feel in various scenarios involving their partners having sex with participants' relatives and nonrelatives. As expected, participants generally reported being very disapproving of a partner's hypothetical infidelity with both their relatives and nonrelatives. However, contrary to predictions generated by kin selection theory, participants tended to report that they would feel worse if their partners had sex with their relatives. We propose several explanations for the current findings and discuss their implications for kin selection theory.
Sick in the Head? Pathogen Concerns Bias Implicit Perceptions of Mental Illness
Authors: Lund Erik M. , Boggero Ian A.
Published: July 2015

Biases against the mentally ill are historically and cross-culturally pervasive, suggesting they may have an evolutionary basis. The prevailing view is that people seek to distance themselves from the mentally ill because they are perceived as dangerous, violent, and incompetent. However, because of similarities between sickness behaviors and symptoms of some mental disorders, it was hypothesized that mental illness stigma could be partially explained as a function of behavioral immune system biases designed to avoid potential sources of contagion. In two experiments, it was found that mental illness was implicitly associated more with disease than danger. In Experiment 1, this implicit association was exacerbated among people who have had their biological immune system activated by a recent illness. In Experiment 2, experimentally priming disease salience increased implicit association between mental illness and disease. Implications for the evolutionary origins of prejudice and the prevention of mental illness stigma are discussed.
Conceptualizing Time Preference: A Life-History Analysis
Authors: Copping Lee T. , Campbell Anne , Muncer Steven
Published: July 2015

Life-history theory (LHT) has drawn upon the concept of “time preference” as a psychological mechanism for the development of fast and slow strategies. However, the conceptual and empirical nature of this mechanism is ill-defined. This study compared four traits commonly used as measures of “time preference” (impulsivity, sensation seeking, future orientation and delay discounting) and evaluated their relationship to variables associated with life-history strategies (aggressive behavior and mating attitudes, biological sex, pubertal timing, victimization, and exposure to aggression in the environment). Results indicated that only sensation seeking consistently showed all the predicted associations, although impulsivity, future orientation, and delay discounting showed some significant associations. A unidimensional higher-order factor of “time preference” did not adequately fit the data and lacked structural invariance across age and sex, suggesting that personality traits associated with LHT do not represent a global trait. We discuss the use of personality traits as measures in LHT and suggest that greater caution and clarity is required when conceptualizing this construct in future work.
U.S. Masters Track Participation Reveals a Stable Sex Difference in Competitiveness
Authors: Deaner Robert O. , Addona Vittorio , Mead Michael P.
Published: July 2015

It is well established that men are more likely than women to engage in direct competition, but it is unclear if this reflects social structural conditions or evolved predispositions. These hypotheses can be addressed by quantifying competitiveness in sports and testing if the sex difference is decreasing over time in the U.S., a society where social roles have converged. Study 1 assessed participation and the occurrence of relatively fast performances by masters runners (40–74 years old) at recent road races and track meets. Fast performances occurred over 20 times more often at track meets than at road races. Women comprised 55% of finishers at roads races but only 15–28% of finishers at track meets. Thus, the sex difference in masters track participation can serve as a measure of the sex difference in competitiveness. Study 2 used data from national championship meets and yearly rankings lists to test whether the sex difference in masters track participation decreased from 1988–2012. The sex difference decreased overall, but there was no evidence of change since the late 1990s. Therefore, the sex difference in the willingness to engage in direct sports competition appears to reflect both social structural conditions and evolved predispositions.
Provision or Good Genes? Menstrual Cycle Shifts in Women's Preferences for Short-Term and Long-Term Mates' Altruistic Behavior
Authors: Oda Ryo , Okuda Akari , Takeda Mia , Hiraishi Kai
Published: July 2015

Men's altruism may have evolved, via female choice, as a signal of either their genetic quality or their willingness to allocate resources to offspring. The possibility that men display altruism to signal their genetic quality may be tested by examining women's preference for men's altruism across the stages of the menstrual cycle. Because women can maximize reproductive benefits by mating with men who have “good genes” on high-fertility versus low-fertility days, women should show a heightened preference for male altruism on high-fertility days compared to low-fertility days, and this heightened preference should be more apparent when women evaluate men for short-term sexual relationships than for long-term committed relationships. The possibility that men display altruism to signal their willingness to provision, as opposed to their genetic quality, may be tested by examining women's preference for men's altruism toward different recipients. More specifically, altruistic behavior toward family members may reflect a willingness to provide resources for kin and, hence, willingness to provision, whereas altruistic behavior toward strangers may function as an honest signal of genetic quality. In two samples of young women (TVs = 131 and 481), we found no differences between high- and low-fertility participants in preference for men's altruism, and women preferred men's altruism more in long-term than short-term relationships. The findings suggest that men's altruistic behavior functions as a signal of willingness to provide resources rather than genetic quality.