bluuebunny/crossref_metadata_2025 huggingface dataset:
An Implicit Theory of Self-Esteem: The Consequences of Perceived Self-Esteem for Romantic Desirability
Authors: Zeigler-Hill Virgil , Myers Erin M.
Published: July 2015

The provision of information appears to be an important property of self-esteem as evidenced by previous research concerning the status-tracking and status-signaling models of self-esteem. The present studies examine whether there is an implicit theory of self-esteem that leads individuals to assume targets with higher levels of self-esteem possess more desirable characteristics than those with lower levels of self-esteem. Across 6 studies, targets with ostensibly higher levels of self-esteem were generally rated as more attractive and as more desirable relationship partners than those with lower levels of self-esteem. It is important to note, however, that this general trend did not consistently emerge for female targets. Rather, female targets with high self-esteem were often evaluated less positively than those with more moderate levels of self-esteem. The present findings are discussed in the context of an extended informational model of self-esteem consisting of both the status-tracking and status-signaling properties of self-esteem.
Surveillance Cues Enhance Moral Condemnation
Authors: Bourrat Pierrick , Baumard Nicolas , McKay Ryan
Published: July 2015

Humans pay close attention to the reputational consequences of their actions. Recent experiments indicate that even very subtle cues that one is being observed can affect cooperative behaviors. Expressing our opinions about the morality of certain acts is a key means of advertising our cooperative dispositions. Here, we investigated how subtle cues of being watched would affect moral judgments. We predicted that participants exposed to such cues would affirm their endorsement of prevailing moral norms by expressing greater disapproval of moral transgressions. Participants read brief accounts of two moral violations and rated the moral acceptability of each violation. Violations were more strongly condemned in a condition where participants were exposed to surveillance cues (an image of eyes interposed between the description of the violation and the associated rating scale) than in a control condition (in which the interposed image was of flowers). We discuss the role that public declarations play in the interpersonal evaluation of cooperative dispositions.
Conceptualizing the Autism Spectrum in Terms of Natural Selection and Behavioral Ecology: The Solitary Forager Hypothesis
Authors: Reser Jared Edward
Published: July 2015

This article reviews etiological and comparative evidence supporting the hypothesis that some genes associated with the autism spectrum were naturally selected and represent the adaptive benefits of being cognitively suited for solitary foraging. People on the autism spectrum are conceptualized here as ecologically competent individuals that could have been adept at learning and implementing hunting and gathering skills in the ancestral environment. Upon independence from their mothers, individuals on the autism spectrum may have been psychologically predisposed toward a different life-history strategy, common among mammals and even some primates, to hunt and gather primarily on their own. Many of the behavioral and cognitive tendencies that autistic individuals exhibit are viewed here as adaptations that would have complemented a solitary lifestyle. For example, the obsessive, repetitive and systemizing tendencies in autism, which can be mistakenly applied toward activities such as block stacking today, may have been focused by hunger and thirst toward successful food procurement in the ancestral past. Both solitary mammals and autistic individuals are low on measures of gregariousness, socialization, direct gazing, eye contact, facial expression, facial recognition, emotional engagement, affiliative need and other social behaviors. The evolution of the neurological tendencies in solitary species that predispose them toward being introverted and reclusive may hold important clues for the evolution of the autism spectrum and the natural selection of autism genes. Solitary animals are thought to eschew unnecessary social contact as part of a foraging strategy often due to scarcity and wide dispersal of food in their native environments. It is thought that the human ancestral environment was often nutritionally sparse as well, and this may have driven human parties to periodically disband. Inconsistencies in group size must have led to inconsistencies in the manner in which natural selection fashioned the social minds of humans, which in turn may well be responsible for the large variation in social abilities seen in human populations. This article emphasizes that individuals on the autism spectrum may have only been partially solitary, that natural selection may have only favored subclinical autistic traits and that the most severe cases of autism may be due to assortative mating.
Is the Social Brain Theory Applicable to Human Individual Differences? Relationship between Sociability Personality Dimension and Brain Size
Authors: Horváth Klára , Martos János , Mihalik Béla , Bódizs Róbert
Published: July 2015

Our study intends to examine whether the social brain theory is applicable to human individual differences. According to the social brain theory primates have larger brains as it could be expected from their body sizes due to the adaptation to a more complex social life. Regarding humans there were few studies about the relationship between theory of mind and frontal and temporal brain lobes. We hypothesized that these brain lobes, as well as the whole cerebrum and neocortex are in connection with the Sociability personality dimension that is associated with individuals' social lives. Our findings support this hypothesis as Sociability correlated positively with the examined brain structures if we control the effects of body size differences and age. These results suggest that the social brain theory can be extended to human interindividual differences and they have some implications to personality psychology too.
Children's Risky Play from an Evolutionary Perspective: The Anti-Phobic Effects of Thrilling Experiences
Authors: Sandseter Ellen Beate Hansen , Kennair Leif Edward Ottesen
Published: July 2015

This theoretical article views children's risky play from an evolutionary perspective, addressing specific evolutionary functions and especially the anti-phobic effects of risky play. According to the non-associative theory, a contemporary approach to the etiology of anxiety, children develop fears of certain stimuli (e.g., heights and strangers) that protect them from situations they are not mature enough to cope with, naturally through infancy. Risky play is a set of motivated behaviors that both provide the child with an exhilarating positive emotion and expose the child to the stimuli they previously have feared. As the child's coping skills improve, these situations and stimuli may be mastered and no longer be feared. Thus fear caused by maturational and age relevant natural inhibition is reduced as the child experiences a motivating thrilling activation, while learning to master age adequate challenges. It is concluded that risky play may have evolved due to this anti-phobic effect in normal child development, and it is suggested that we may observe an increased neuroticism or psychopathology in society if children are hindered from partaking in age adequate risky play.
Is There a Sensitive Period in Human Incest Avoidance?
Authors: Luo Liqun
Published: July 2015

Many studies support the proposition that early cosocialization with opposite-sex children has the effect of inhibiting later mutual sexual attraction, but the existence of a period in the life cycle in which individuals are sensitive to the effect of early cosocialization has been a matter of controversy. Drawing on earlier traditional psychological research, and on more recent work guided by parental investment theory, we hypothesized that only for maternal perinatal association (MPA)-absent males a less-than-around-three-years age difference with the sister can predict stronger aversion to sibling incest. The results corroborated the hypothesis. The results can be interpreted as support for the existence of a sensitive period as well as for the potent role of MPA. Cross-cultural comparative studies were called on to further test the hypothesis.
Predicting Preferences for Sex Acts: Which Traits Matter Most, and Why?
Authors: Peterson Ashley , Geher Glenn , Kaufman Scott Barry
Published: July 2015

Several dispositional traits have been examined in mating contexts by evolutionary psychologists. Such traits include life history strategy, sociosexuality, and the Big Five. Recently, scholars have examined the validity and predictive utility of mating intelligence, a new construct designed to capture the cognitive processes that underlie mating psychology. The current research employed a battery of dispositional traits that include all these constructs in an effort to predict preferences for different kinds of sex acts. Sexual acts vary wildly, and the ability to predict this variability may well hold an important key to underlying sexual strategies. A sample of 607 young adults (144 males and 463 females) completed measures of each of these traits as well as a measure of preference for specific sex acts (along with providing information on their sexual orientation). The traits predicted variability in preference for sex acts – with mating intelligence being the most predictive (for instance, mating intelligence was positively related to preference for vaginal intercourse across the sexes). Sex differences emerged (e.g., males show a stronger preference for anal sex than do females). Discussion focuses on (a) sex differences in preference for sex acts along with (b) why the trait variables predicted preferences in sex acts.
Songs as a Medium for Embedded Reproductive Messages
Authors: Hobbs Dawn R. , Gallup Gordon G.
Published: July 2015

Research shows that sensational news stories as well as popular romance novels often feature themes related to important topics in evolutionary psychology. In the first of four studies described in this paper we examined the song lyrics from three Billboard charts: Country, Pop, and R&B. A content analysis of the lyrics revealed 18 reproductive themes that read like an outline for a course in evolutionary psychology. Approximately 92% of the 174 songs that made it into the Top Ten in 2009 contained one or more reproductive messages, with an average of 10.49 reproductive phrases per song. Although differences in the frequency of different themes between charts were found, further analyses showed that the most popular/bestselling songs contained significantly more reproductive messages. An analysis of the lyrics of opera arias and art songs also revealed evidence for many of the same embedded reproductive messages extending back more than 400 years.
Parent-Offspring Conflict over Mating: Testing the Tradeoffs Hypothesis
Authors: Apostolou Menelaos
Published: July 2015

The difference in genetic relatedness between parents and offspring results into traits such as beauty being more beneficial in a spouse than in an in-law. As a consequence, mate and in-law preferences do not overlap, and each party tends to prefer more the traits that give it more benefits. This paper tests the hypothesis that this divergence in preferences interacts with the tradeoffs nature of mating to give rise to parent-offspring conflict over mating. In particular, using a design where mate choice is constrained by a budget, three hypotheses are tested: First, asymmetries between in-law and mate preferences result in asymmetrical compromises in the choice of an in-law and a spouse. Second, the hypothesis is tested that when choice is constrained, disagreement spreads to traits where there is no divergence between in-law and mate preferences. Finally, it is hypothesized that there is a negative relationship between mate value and parent-offspring conflict over mating. Evidence from two independent studies in two different countries provides support for all three hypotheses.
Prenatal Influences on Sexual Orientation: Digit Ratio (2D:4D) and Number of Older Siblings
Authors: Kangassalo Katariina , Pölkki Mari , Rantala Markus J.
Published: July 2015

Prenatal androgen levels are suggested to influence sexual orientation in both sexes. The 2D:4D digit ratio has been found to associate with sexual orientation, but published findings have often been contradictory, which may partly be due to the large ethnic diversity between and within studied populations. In men, number of older brothers has been found to correlate positively with homosexuality. This phenomenon has been explained with a maternal immune reaction, which is provoked only by male fetuses and which gets stronger after each pregnancy. Here we assessed the relationship of sexual orientation to 2D:4D ratios and number of older siblings in Finland, where the population is found to be genetically relatively homogeneous. As in many previous studies, heterosexual men had lower 2D:4D than non-heterosexual men, which supports the notion that non-heterosexual men experience higher androgen levels in utero than population norms. Contrary to previous reports, non-heterosexual women had higher 2D:4D than heterosexual women. Non-heterosexual men had more older brothers and older sisters than heterosexual men. The greater number of older sisters in non-heterosexual men indicates that there are other factors that contribute to the higher birth order of homosexual men than the maternal immunization.
Acute Stress Eliminates Female Advantage in Detection of Ambiguous Negative Affect
Authors: DeDora Daniel J. , Carlson Joshua M. , Mujica-Parodi Lilianne R.
Published: July 2015

The human stress response evolved to maximize an individual's probability of survival when threatened. The present study addressed whether physical danger modulates perception of an unrelated ambiguous threat and, if so, to what extent this response is sex-specific. The authors utilized a first-time tandem skydive as a stressor, which had been previously validated as producing a highly-controlled, genuinely stressful environment. In a counter-balanced within-subjects design, participants wore a virtual reality helmet to complete an emotion-identification task during the plane's ascent (stress condition) and in the laboratory (control condition). Participants were presented static male faces morphed between 20–80% aggression, which gradually emerged from degraded images. Using a binary forced-choice design, participants identified each ambiguous face as aggressive or neutral. Results showed that participants characterized emotion more rapidly under stress versus control conditions. Unexpectedly, the results also show that while women were more sensitive to affect ambiguity than men under control conditions, they exhibited a marked decrease in sensitivity equivalent to men while under stress.
Friends with Benefits: The Evolved Psychology of Same- and Opposite-Sex Friendship
Authors: Lewis David M.G. , Conroy-Beam Daniel , Al-Shawaf Laith , Raja Annia , DeKay Todd , Buss David M.
Published: July 2015

During human evolution, men and women faced distinct adaptive problems, including pregnancy, hunting, childcare, and warfare. Due to these sex-linked adaptive problems, natural selection would have favored psychological mechanisms that oriented men and women toward forming friendships with individuals possessing characteristics valuable for solving these problems. The current study explored sex-differentiated friend preferences and the psychological design features of same- and opposite-sex friendship in two tasks. In Task 1, participants ( N = 121) categorized their same-sex friends (SSFs) and opposite-sex friends (OSFs) according to the functions these friends serve in their lives. In Task 2, participants designed their ideal SSFs and OSFs using limited budgets that forced them to make trade-offs between the characteristics they desire in their friends. In Task 1, men, more than women, reported maintaining SSFs for functions related to athleticism and status enhancement and OSFs for mating opportunities. In Task 2, both sexes prioritized agreeableness and dependability in their ideal SSFs, but men prioritized physical attractiveness in their OSFs, whereas women prioritized economic resources and physical prowess. These findings suggest that friend preferences may have evolved to solve ancestrally sex-linked adaptive problems, and that opposite-sex friendship may directly or indirectly serve mating functions.
The Effect of Individual Differences and Manipulated Life Expectancies on the Willingness to Engage in Sexual Coercion
Authors: Dunkel Curtis S. , Mathes Eugene
Published: July 2015

The role of the individual difference variables of mate value, short-term and long-term mating preferences, and life history strategy along with the manipulated variable of life expectancy were used to predict differences in the willingness to engage in sexually coercive behaviors. Short-term preferences and long-term preferences were correlated with the willingness to engage in sexual coercion at all life expectancies. Life history strategy was correlated with the willingness to engage in sexual coercion at only the shortest and longest life expectancies. Most importantly short-term and long-term mating preferences interacted with life expectancy to predict the willingness to engage in sexually coercive behaviors. Short life expectancies increased willingness in individuals with high short-term and low long-term preferences. The results are discussed in terms of the varying theories of sexual coercion with emphasis put on a life history approach.
On the Evolution of Sport
Authors: Lombardo Michael P.
Published: July 2015

Sports have received little attention from evolutionary biologists. I argue that sport began as a way for men to develop the skills needed in primitive hunting and warfare, then developed to act primarily as a lek where athletes display and male spectators evaluate the qualities of potential allies and rivals. This hypothesis predicts that (1) the most popular modern male sports require the skills needed for success in male-male physical competition and primitive hunting and warfare; (2) champion male athletes obtain high status and thereby reproductive opportunities in ways that parallel those gained by successful primitive hunters and warriors; (3) men pay closer attention than do women to male sports so they can evaluate potential allies and rivals; and (4) male sports became culturally more important when opportunities to evaluate potential allies and rivals declined as both the survival importance of hunting and the proportion of men who experience combat decreased. The characteristics of primitive and modern sports are more consistent with these predictions than those generated by intersexual sexual selection theories of sport.
Evolutionary Psychology is Compatible with Equity Feminism, but Not with Gender Feminism: A Reply to
Authors: Kuhle Barry X.
Published: July 2015

I comment on Eagly and Wood's biosocial constructionist evolutionary theory (2011; DOI: 10.1007/s11199-011-9949-9). Although this gender feminist theory allows for evolved physical differences between men and women and evolved psychological similarities for men and women, it fails to consider evolutionary accounts of psychological sex differences. I hypothesize that gender feminists' reluctance to acknowledge that evolution has left different fingerprints on men's and women's bodies and brains stems from two common misunderstandings of evolutionary psychology: the myth of immutability and the naturalistic fallacy. I conclude that although evolutionary psychology is eminently compatible with equity feminism, evolutionary psychology and feminist psychology will conflict as long as the latter adheres to gender feminism and its unwillingness to acknowledge the evidence for evolved psychological sex differences. Gender feminism's dualistic view of evolution hinders the search for and understanding of the proximate and ultimate causes of inequality. Feminist psychology needs to evolve by embracing equity feminism, which has no a priori stance on the origin or existence of differences between the sexes.
Female Facial Appearance and Health
Authors: Gray Alan W. , Boothroyd Lynda G.
Published: July 2015

The current study addressed whether rated femininity, attractiveness, and health in female faces are associated with numerous indices of self-reported health history (number of colds/stomach bugs/frequency of antibiotic use) in a sample of 105 females. It was predicted that all three rating variables would correlate negatively with bouts of illness (with the exception of rates of stomach infections), on the assumption that aspects of facial appearance signal mate quality. The results showed partial support for this prediction, in that there was a general trend for both facial femininity and attractiveness to correlate negatively with the reported number of colds in the preceding twelve months and with the frequency of antibiotic use in the last three years and the last twelve months. Rated facial femininity (as documented in September) was also associated with days of flu experienced in the period spanning the November-December months. However, rated health did not correlate with any of the health indices (albeit one marginal result with antibiotic use in the last twelve months). The results lend support to previous findings linking facial femininity to health and suggest that facial femininity may be linked to some aspects of disease resistance but not others.
Sex Differences in In-Group Cooperation Vary Dynamically with Competitive Conditions and Outcomes
Authors: Bailey Drew H. , Winegard Benjamin , Oxford Jon , Geary David C.
Published: July 2015

Men's but not women's investment in a public goods game varied dynamically with the presence or absence of a perceived out-group. Three hundred fifty-four (167 male) young adults participated in multiple iterations of a public goods game under intergroup and individual competition conditions. Participants received feedback about whether their investments in the group were sufficient to earn a bonus to be shared among all in-group members. Results for the first trial confirm previous research in which men's but not women's investments were higher when there was a competing out-group. We extended these findings by showing that men's investment in the in-group varied dynamically by condition depending on the outcome of the previous trial: In the group condition, men, but not women, decreased spending following a win (i.e., earning an in-group bonus). In the individual condition, men, but not women, increased spending following a win. We hypothesize that these patterns reflect a male bias to calibrate their level of in-group investment such that they sacrifice only what is necessary for their group to successfully compete against a rival group.
Automatic Attention towards Face or Body as a Function of Mating Motivation
Authors: Lu Hui Jing , Chang Lei
Published: July 2015

Because women's faces and bodies carry different cues of reproductive value, men may attend to different perceptual cues as functions of their long-term versus short-term mating motivations. We tested this hypothesis in three experiments on 135 male and 132 female participants. When influenced by short-term rather than long-term mating motivations, men's attention was captured by (Study 1), was shifted to (Study 2), and was distracted by (Study 3) the waist/hip area rather than the face on photographs of attractive women. Similar effects were not found among the female participants in response to photographs of attractive men. These results support the evolutionary view that, similar to the attentional selectivity found in other domains of life, male perceptual attention has evolved to selectively capture and hold reproductive information about the opposite sex as a function of short-term versus long-term mating goals.
Between-Sex Differences in Romantic Jealousy: Substance or Spin? A Qualitative Analysis
Authors: Fussell Nicola J. , Stollery Brian T.
Published: July 2015

An influential evolutionary account of romantic jealousy proposes that natural selection shaped a specific sexually-dimorphic psychological mechanism in response to relationship threat. However, this account has faced considerable theoretical and methodological criticism and it remains unclear whether putative sex differences in romantic jealousy actually exist and, if they do, whether they are consistent with its predictions. Given the multidimensional nature of romantic jealousy, the current study employed a qualitative design to examine these issues. We report the results of sixteen semi-structured interviews that were conducted with heterosexual men and women with the purpose of exploring the emotions, cognitions and behaviors that formed their subjective, lived experience in response to relationship threat. Interpretative phenomenological analysis revealed four super-ordinate themes (“threat appraisal”, “emotional episodes”, “sex-specific threat” and “forgive and forget”) and unequivocal sex differences in romantic jealousy consistent with the evolutionary account. Self-esteem, particularly when conceptualized as an index of mate value, emerged as an important proximal mediator for both sexes. However, specific outcomes were dependent upon domains central to the individual's self concept that were primarily sex-specific. The findings are integrated within the context of existing self-esteem and evolutionary theory and future directions for romantic jealousy research are suggested.
Sleep-Wake State Tradeoffs, Impulsivity and Life History Theory
Authors: Miller Alissa A. , Rucas Stacey L.
Published: July 2015

Evolutionary ecological theory predicts that sleep-wake state tradeoffs may be related to local environmental conditions and should therefore correlate to alterations in behavioral life history strategies. It was predicted that firefighters who slept more and reported better quality sleep on average would exhibit lower impulsivity inclinations related to slower life history trajectories. UPPS impulsivity scores and self-reported sleep averages were analyzed and indicated a negative association between sleep variables and urgency and a positive association with premeditation. Perseverance, and in some cases premeditation, however, disclosed an unpredicted marginally significant positive association between increased and emergency nighttime waking-related sleep deprivation. Sensation seeking was not associated with sleep variables, but was strongly associated with number of biological children. This research contributes to understanding the implications of human sleep across ecological and behavioral contexts and implies further research is necessary for constructing evolutionarily oriented measures of impulsivity inclination and its meaning in the context of life history strategies.
The Lurking Snake in the Grass: Interference of Snake Stimuli in Visually Taxing Conditions
Authors: Soares Sandra Cristina
Published: July 2015

Based on evolutionary considerations, it was hypothesized that humans have been shaped to easily spot snakes in visually cluttered scenes that might otherwise hide camouflaged snakes. This hypothesis was tested in a visual search experiment in which I assessed automatic attention capture to evolutionarily-relevant distractor stimuli (snakes), in comparison with another animal which is also feared but where this fear has a disputed evolutionary origin (spiders), and neutral stimuli (mushrooms). Sixty participants were engaged in a task that involved the detection of a target (a bird) among pictures of fruits. Unexpectedly, on some trials, a snake, a spider, or a mushroom replaced one of the fruits. The question of interest was whether the distracting stimuli slowed the reaction times for finding the target (the bird) to different degrees. Perceptual load of the task was manipulated by increments in the set size (6 or 12 items) on different trials. The findings showed that snake stimuli were processed preferentially, particularly under conditions where attentional resources were depleted, which reinforced the role of this evolutionarily-relevant stimulus in accessing the visual system ( Isbell, 2009 ).
Human Nonindependent Mate Choice: Is Model Female Attractiveness Everything?
Authors: Vakirtzis Antonios , Roberts S. Craig
Published: July 2015

Following two decades of research on non-human animals, there has recently been increased interest in human nonindependent mate choice, namely the ways in which choosing women incorporate information about a man's past or present romantic partners (‘model females’) into their own assessment of the male. Experimental studies using static facial images have generally found that men receive higher desirability ratings from female raters when presented with attractive (compared to unattractive) model females. This phenomenon has a straightforward evolutionary explanation: the fact that female mate value is more dependent on physical attractiveness compared to male mate value. Furthermore, due to assortative mating for attractiveness, men who are paired with attractive women are more likely to be of high mate value themselves. Here, we also examine the possible relevance of model female cues other than attractiveness (personality and behavioral traits) by presenting video recordings of model females to a set of female raters. The results confirm that the model female's attractiveness is the primary cue. Contrary to some earlier findings in the human and nonhuman literature, we found no evidence that female raters prefer partners of slightly older model females. We conclude by suggesting some promising variations on the present experimental design.
Different Cues of Personality and Health from the Face and Gait of Women
Authors: Kramer Robin S. S. , Gottwald Victoria M. , Dixon Thomas A. M. , Ward Robert
Published: July 2015

Redundant cues for attractiveness in humans have been identified, but the idea of multiple systems displaying different socially-relevant traits has yet to be extensively examined. We compared the accuracy with which observers could identify socially-relevant information of female targets, both from static images of their faces, and from point-light displays of their gait. Perception of extraversion was at chance. However, agreeableness and sociosexuality were more accurately perceived from the face than gait, while physical health showed the opposite pattern. This double dissociation suggests different information can be carried in different modalities. In addition, partial correlation analyses suggested that even when both modalities allowed accurate trait identification, the information content was different. Our results demonstrate that cues of different socially-relevant traits are communicated more effectively through different modalities, and these modality-specific cues contain distinctive information, supporting a “multiple messages” hypothesis.
Birth Weight Predicts Scores on the ADHD Self-Report Scale and Attitudes towards Casual Sex in College Men: A Short-Term Life History Strategy?
Authors: Frederick Michael J.
Published: July 2015

Early development can have long-term effects on physiology and behavior. While severe disturbances predictably lead to dysfunction, recent work in humans and animals has led to a growing appreciation for the more subtle ways in which early conditions can modulate behavioral tendencies later in life. Life history theory predicts that early cues signaling a stressful or suboptimal environment might lead an organism to adopt a strategy favoring short-term gains and early reproduction. Fifty college men reported their birth weight, completed the Attention-Deficit/Hyperactivity Disorder (ADHD) Self-Report Scale, and answered a series of questions about their sexual history and attitudes towards short-term sexual encounters. Lower birth weights were associated with higher scores on the ADHD scale ( r = −.352; p ≤ .05) and more favorable attitudes towards casual sex ( r = −.456; p ≤ 0.001). There was a significant interaction between birth weight and casual sex favorability in predicting number of sexual partners ( F1,4 6 = 4.994; p ≤ .05). This suggests that, although men who are smaller at birth may otherwise be at a disadvantage in reproductive terms, they may offset their reduced fitness by being more willing to engage in casual sex.
Smiles as Signals of Lower Status in Football Players and Fashion Models: Evidence That Smiles are Associated with Lower Dominance and Lower Prestige
Authors: Ketelaar Timothy , Koenig Bryan L. , Gambacorta Daniel , Dolgov Igor , Hor Daniel , Zarzosa Jennifer , Luna-Nevarez Cuauhtémoc , Klungle Micki , Wells Lee
Published: July 2015

Across four studies, the current paper demonstrates that smiles are associated with lower social status. Moreover, the association between smiles and lower status appears in the psychology of observers and generalizes across two forms of status: prestige and dominance. In the first study, faces of fashion models representing less prestigious apparel brands were found to be more similar to a canonical smile display than the faces of models representing more prestigious apparel brands. In a second study, after being experimentally primed with either high or low prestige fashion narratives, participants in the low prestige condition were more likely to perceive smiles in a series of photographs depicting smiling and non-smiling faces. A third study of football player photographs revealed that the faces of less dominant (smaller) football players were more similar to the canonical smile display than the faces of their physically larger counterparts. Using the same football player photographs, a fourth study found that smiling was a more reliable indicator of perceived status-relevant personality traits than perceptions of the football players' physical sizes inferred from the photographs.
What Have You Done for Me Lately? Friendship-Selection in the Shadow of the Dark Triad Traits
Authors: Jonason Peter K. , Schmitt David P.
Published: July 2015

The current studies examined how the Dark Triad personality traits (i.e., Machiavellianism, narcissism, and psychopathy) facilitate the strategic structuring of an individual's social environment in terms of same- and opposite-sex friends. In one study using normative questions ( N = 267) and another using a budget-allocation task ( N = 114), we found that the Dark Triad traits were associated with choosing friends for strategic purposes and to create a volatile environment. Narcissistic individuals reported relatively more reasons to form friendships, such as shared interests, makes me feel good, and intelligence. Women high in narcissism chose same-sex friends who were attractive and women high on Machiavellianism chose same-sex friends who have social status. Men high on psychopathy devalued traits associated with good social relationships in favor of friends who could facilitate their mating efforts and to offset risks incurred in their life history strategy. Results are discussed using the selection-manipulation-evocation framework for explaining how personality traits interact with social environments and integrated with findings from evolutionary biology.
From One Extreme to the Other: Negative Evaluation Anxiety and Disordered Eating as Candidates for the Extreme Female Brain
Authors: Bremser Jennifer A. , Gallup Gordon G.
Published: July 2015

Simon Baron-Cohen pioneered the idea that different brain types evolved to process information in gender specific ways. Here we expand this approach to looking at eating disorders as a byproduct of the extreme female brain. The incidence of eating disorders is higher among females, and recent findings show that hormones may play a role in eating disorders. We present new evidence from four studies that both an empathizing bias and hyper-mentalizing (as measures of the extreme female brain; EFB) are related to disordered eating and negative evaluation anxiety in women. We also advance the novel hypothesis that concerns about animal welfare (a unique expression of the EFB) may account for the relationship between vegetarianism and eating disorders.
The Impact of Premature Childbirth on Parental Bonding
Authors: Hoffenkamp Hannah N. , Tooten Anneke , Hall Ruby A.S. , Croon Marcel A. , Braeken Johan , Winkel Frans Willem , Vingerhoets Ad J.J.M. , van Bakel Hedwig J.A.
Published: July 2015

The development of an affectionate parent-infant bond is essential for a newborn infant's survival and development. However, from evolutionary theory it can be derived that parental bonding is not an automatic process, but dependent on infants' cues to reproductive potential and parents' access to resources. The purpose of the present study was to examine the process of bonding in a sample of Dutch mothers ( n = 200) and fathers ( n = 193) of full-term ( n = 69), moderately premature ( n = 68), and very premature infants ( n = 63). During the first month postpartum parents completed the Pictorial Representation of Attachment Measure (PRAM) and Postpartum Bonding Questionnaire (PBQ). Longitudinal analyses revealed that mothers' PRAM scores decreased after moderately preterm delivery, whereas decreases in PRAM scores occurred in both parents after very preterm delivery. As lower PRAM scores represent stronger feelings of parent-infant connectedness, our findings suggest a higher degree of bonding after premature childbirth. Results of the PBQ analysis were in line with PRAM outcomes, as parents of preterm infants reported less bonding problems compared to parents of full-terms. These findings support the hypothesis that in affluent countries with adequate resources, bonding in parents of preterm infants on average may be higher than in parents of full-term infants.
Redness Enhances Perceived Aggression, Dominance and Attractiveness in Men's Faces
Authors: Stephen Ian D. , Oldham Francesca H. , Perrett David I. , Barton Robert A.
Published: July 2015

In a range of non-human primate, bird and fish species, the intensity of red coloration in males is associated with social dominance, testosterone levels and mate selection. In humans too, skin redness is associated with health, but it is not known whether – as in non-human species – it is also associated with dominance and links to attractiveness have not been thoroughly investigated. Here we allow female participants to manipulate the CIELab a* value (red-green axis) of skin to maximize the perceived aggression, dominance and attractiveness of photographs of men's faces, and make two findings. First, participants increased a* (increasing redness) to enhance each attribute, suggesting that facial redness is perceived as conveying similar information about a male's qualities in humans as it does in non-human species. Second, there were significant differences between trial types: the highest levels of red were associated with aggression, an intermediate level with dominance, and the least with attractiveness. These differences may reflect a trade-off between the benefits of selecting a healthy, dominant partner and the negative consequences of aggression.
Body Image and Body Type Preferences in St. Kitts, Caribbean: A Cross-Cultural Comparison with U.S. Samples regarding Attitudes towards Muscularity, Body Fat, and Breast Size
Authors: Gray Peter B. , Frederick David A.
Published: July 2015

We investigated body image in St. Kitts, a Caribbean island where tourism, international media, and relatively high levels of body fat are common. Participants were men and women recruited from St. Kitts ( n = 39) and, for comparison, U.S. samples from universities ( n = 618) and the Internet ( n = 438). Participants were shown computer generated images varying in apparent body fat level and muscularity or breast size and they indicated their body type preferences and attitudes. Overall, there were only modest differences in body type preferences between St. Kitts and the Internet sample, with the St. Kitts participants being somewhat more likely to value heavier women. Notably, however, men and women from St. Kitts were more likely to idealize smaller breasts than participants in the U.S. samples. Attitudes regarding muscularity were generally similar across samples. This study provides one of the few investigations of body preferences in the Caribbean.
Men Smelling Women: Null Effects of Exposure to Ovulatory Sweat on Men's Testosterone
Authors: Roney James R. , Simmons Zachary L.
Published: July 2015

Males of many species, humans included, exhibit rapid testosterone increases after exposure to conspecific females. Female chemical stimuli are sufficient to trigger these responses in many nonhuman species, which raises the possibility of similar effects in humans. Recently, Miller and Maner (2010) reported that smelling T-shirts worn by women near ovulation can trigger testosterone responses in men; however, men were aware that they were smelling women's scents, and thus mental imagery associated with that knowledge may have contributed to the hormone responses. Here, we collected axillary sweat samples from women on days near ovulation. In a crossover design, men who were not explicitly aware of the specific stimuli smelled the sweat samples in one session and water samples in a second session. There were no differences in testosterone responses across the experimental conditions. Our null findings suggest that the relevant chemical signal is not found in axillary sweat, and/or that knowledge of the stimulus source is necessary for hormone responses. These results thus suggest boundary conditions for the effects reported in Miller and Maner (2010) , and recommend further research to define the precise circumstances under which men's testosterone may respond to chemosensory cues from women.
Immediate Survival Focus: Synthesizing Life History Theory and Dual Process Models to Explain Substance Use
Authors: Richardson George B. , Hardesty Patrick
Published: July 2015

Researchers have recently applied evolutionary life history theory to the understanding of behaviors often conceived of as prosocial or antisocial. In addition, researchers have applied cognitive science to the understanding of substance use and used dual process models, where explicit cognitive processes are modeled as relatively distinct from implicit cognitive processes, to explain and predict substance use behaviors. In this paper we synthesized these two theoretical perspectives to produce an adaptive and cognitive framework for explaining substance use. We contend that this framework provides new insights into the nature of substance use that may be valuable for both clinicians and researchers.
Inclusive Fitness Affects Both Prosocial and Antisocial Behavior: Target Gender and Insult Domain Moderate the Link between Genetic Relatedness and Aggression
Authors: Gesselman Amanda N. , Webster Gregory D.
Published: July 2015

Although prior research has examined the relationship between genetic relatedness and helping behavior (Burnstein, Crandall, and Kitayama, 1994), less is known about its role in aggressive responses to insults ( Fitzgerald and Ketterer, 2011 ). Drawing on inclusive fitness theory ( Hamilton, 1964 ) and the Kinship, Acceptance, and Rejection Model of Altruism and Aggression (KARMAA; Webster, 2008 ; Webster et al., 2012 ), we designed a 2 (participant gender) × 2 (target gender) × 2 (insult: status vs. reproductive) × 3 (relatedness: stranger vs. cousin vs. sibling) between-person experiment in which 489 participants (a) read vignettes in which a stranger, cousin, or sibling was insulted and (b) reported their emotional reaction and retaliation likelihood (six-item α= .91) in response to the insult. Consistent with theory and prior research, men were significantly more aggressive than women, and people were significantly more aggressive responding to insults against kin than non-kin. These findings support theoretically-derived, dynamic, and domain-specific links among insults, gender, relatedness, and aggression.
Evolutionary Psychology in the Modern World: Applications, Perspectives, and Strategies
Authors: Roberts S. Craig , van Vugt Mark , Dunbar Robin I. M.
Published: July 2015

An evolutionary approach is a powerful framework which can bring new perspectives on any aspect of human behavior, to inform and complement those from other disciplines, from psychology and anthropology to economics and politics. Here we argue that insights from evolutionary psychology may be increasingly applied to address practical issues and help alleviate social problems. We outline the promise of this endeavor, and some of the challenges it faces. In doing so, we draw parallels between an applied evolutionary psychology and recent developments in Darwinian medicine, which similarly has the potential to complement conventional approaches. Finally, we describe some promising new directions which are developed in the associated papers accompanying this article.
Does Theorizing on Reciprocal Altruism Apply to the Relationships of Individuals with a Spinal Cord Injury?
Authors: Buunk A.P. , Zurriaga Rosario , González Pilar
Published: July 2015

From the perspective of reciprocal altruism, we examined the role of reciprocity in the close relationships of people inflicted with a spinal cord injury (SCI) ( n = 70). We focused on the help receiver rather than on the help giver. Participants perceived more reciprocity in relationships with friends than in relationships with the partner and with family members. In these last relationships, perceptions of indebtedness were more prevalent than perceptions of deprivation. However, most negative feelings were evoked by a lack of reciprocity in partner relationships, followed by family relationships, and next by friendships. Moreover, depression was especially associated with a lack of perceived reciprocity in the relationships with family, and somewhat less with a lack of perceived reciprocity in the relationship with the partner. These results underline the importance of reciprocity in relationships, but suggest that reciprocity may be more, rather than less important in partner and family relationships.
An Evolutionary Perspective on Health Psychology: New Approaches and Applications
Authors: Tybur Joshua M. , Bryan Angela D. , Hooper Ann E. Caldwell
Published: July 2015

Although health psychologists' efforts to understand and promote health are most effective when guided by theory, health psychology has not taken full advantage of theoretical insights provided by evolutionary psychology. Here, we argue that evolutionary perspectives can fruitfully inform strategies for addressing some of the challenges facing health psychologists. Evolutionary psychology's emphasis on modular, functionally specialized psychological systems can inform approaches to understanding the myriad behaviors grouped under the umbrella of “health,” as can theoretical perspectives used by evolutionary anthropologists, biologists, and psychologists (e.g., Life History Theory). We detail some early investigations into evolutionary health psychology, and we provide suggestions for directions for future research.