Lordosis in Humans

Despite progress in attractiveness research, we have yet to identify many fitness-relevant cues in the human phenotype or humans' psychology for responding to them. Here, we test hypotheses about psychological systems that may have evolved to process distinct cues in the female lumbar region. The Fetal Load Hypothesis proposes a male preference for a morphological cue: lumbar curvature. The Lordosis Detection Hypothesis posits context-dependent male attraction to a movement: lordosis behavior. In two studies (Study 1 N: 102, Study 2 N: 231), we presented men with animated female characters that varied in their lumbar curvature and back arching (i.e., lordosis behavior). Irrespective of mating context, men's attraction increased as lumbar curvature approached the hypothesized optimum. By contrast, men experienced greater attraction to lordosis behavior in short-term than long-term mating contexts. These findings support both the Lordosis Detection and Fetal Load Hypotheses. Discussion focuses on the meaning of human lordosis and the importance of dynamic stimuli in attractiveness research.

The role of developmental caregiving programming in modulating our affiliation tendency and the vulnerability to social anxiety and eating disorders

Attachment is the evolutionarily-established process through which humans create bonds with others to receive care from them. The phenomenon is as essential to our physical survival as it is to our psychological development. An increasing number of studies demonstrates that in sensitive periods during the early years of life, our brain circuitry is programmed in the interactions with our caregivers, with the imprinting of information over multiple attachment dimensions. Adopting a basic brain-computer analogy, we can think of this knowledge as the psycho-social firmware of our mind. According to a recently proposed extension of the classical three-dimensional view, one attachment dimension - somaticity - concerns the caregiver's task of reflecting and confirming the child's (internal) states - such as sensations, emotions, and representations - to support the child's ability to identify and define those entities autonomously. Relying on multidisciplinary evidence - from neuroscientific, developmental, evolutionary, and clinical sources - we suggest that somaticity (H1) has the adaptive function to modulate our tendency to comply and affiliate with a reference group but also (H2) increases the vulnerability to developing Social Anxiety (SA) and Eating Disorders (EDs). We evaluate H1-H2, (1) indicating the evolutionary role of somaticity in modulating our affiliation tendency to optimize the ancestral threat-opportunity balance coming from infectious diseases and (2) showing the deep connection between SA-EDs and the features most closely related to somaticity - interoception and parenting style. Finally, we discuss three relevant implications of H1-H2: (A) Bringing into research focus the adaptive role of our firmware knowledge system versus the hardware (neural substrate) and software (higher cognition) ones. (B) Complementing the well-grounded Objectification and Allocentric Lock Theories, allowing us to integrate multiple levels of explanation on the etiology of psychopathology. (C) Suggesting the design of new psychological treatments. While not aiming to prove H1-H2, our analysis supports them and encourages their direct testing.

On the evolution of epigenetics via exaptation: A developmental systems perspective

Evolution and development are interrelated processes influenced by genomic, epigenetic, and environmental factors. Epigenetic processes serve critical roles in development and operate as intermediaries that connect the genome to the rest of the world. Therefore, it is of interest to consider the evolution of epigenetic processes. The developmental systems perspective offers a distinctive, coherent, integrative way to understand the relationships between evolution, epigenetics, development, and the effects of experienced contexts. By adopting this perspective, this paper draws attention to the role of exaptation in the evolution of epigenetics in the RNA world and addresses the role of epigenetics in the later evolution of developmental processes such as cellular differentiation, learning, and memory. In so doing, the paper considers the appearance and functions of epigenetics in evolutionary history-sketching a pathway by which epigenetic processes might have evolved via exaptation and then contributed to the later development and evolution of phenotypes.

Romantic love evolved by co-opting mother-infant bonding

For 25 years, the predominant evolutionary theory of romantic love has been Fisher's theory of independent emotion systems. That theory suggests that sex drive, romantic attraction (romantic love), and attachment are associated with distinct neurobiological and endocrinological systems which evolved independently of each other. Psychological and neurobiological evidence, however, suggest that a competing theory requires attention. A theory of co-opting mother-infant bonding sometime in the recent evolutionary history of humans may partially account for the evolution of romantic love. I present a case for this theory and a new approach to the science of romantic love drawing on human psychological, neurobiological, and (neuro)endocrinological studies as well as animal studies. The hope is that this theoretical review, along with other publications, will generate debate in the literature about the merits of the theory of co-opting mother-infant bonding and a new evolutionary approach to the science of romantic love.

Nocturnal selective pressures on the evolution of human musicality as a missing piece of the adaptationist puzzle

Human musicality exhibits the necessary hallmarks for biological adaptations. Evolutionary explanations focus on recurrent adaptive problems that human musicality possibly solved in ancestral environments, such as mate selection and competition, social bonding/cohesion and social grooming, perceptual and motor skill development, conflict reduction, safe time-passing, transgenerational communication, mood regulation and synchronization, and credible signaling of coalition and territorial/predator defense. Although not mutually exclusive, these different hypotheses are still not conceptually integrated nor clearly derived from independent principles. I propose The Nocturnal Evolution of Human Musicality and Performativity Theory in which the night-time is the missing piece of the adaptationist puzzle of human musicality and performing arts. The expansion of nocturnal activities throughout human evolution, which is tied to tree-to-ground sleep transition and habitual use of fire, might help (i) explain the evolution of musicality from independent principles, (ii) explain various seemingly unrelated music features and functions, and (iii) integrate many ancestral adaptive values proposed. The expansion into the nocturnal niche posed recurrent ancestral adaptive challenges/opportunities: lack of luminosity, regrouping to cook before sleep, imminent dangerousness, low temperatures, peak tiredness, and concealment of identity. These crucial night-time features might have selected evening-oriented individuals who were prone to acoustic communication, more alert and imaginative, gregarious, risk-taking and novelty-seeking, prone to anxiety modulation, hedonistic, promiscuous, and disinhibited. Those night-time selected dispositions may have converged and enhanced protomusicality into human musicality by facilitating it to assume many survival- and reproduction-enhancing roles (social cohesion and coordination, signaling of coalitions, territorial defense, antipredatorial defense, knowledge transference, safe passage of time, children lullabies, and sexual selection) that are correspondent to the co-occurring night-time adaptive challenges/opportunities. The nocturnal dynamic may help explain musical features (sound, loudness, repetitiveness, call and response, song, elaboration/virtuosity, and duetting/chorusing). Across vertebrates, acoustic communication mostly occurs in nocturnal species. The eveningness chronotype is common among musicians and composers. Adolescents, who are the most evening-oriented humans, enjoy more music. Contemporary tribal nocturnal activities around the campfire involve eating, singing/dancing, storytelling, and rituals. I discuss the nocturnal integration of musicality's many roles and conclude that musicality is probably a multifunctional mental adaptation that evolved along with the night-time adaptive landscape.

Sex/gender differences in cognitive abilities

Sex/gender differences in cognitive sciences are riddled by conflicting perspectives. At the center of debates are clinical, social, and political perspectives. Front and center, evolutionary and biological perspectives have often focused on 'nature' arguments, while feminist and constructivist views have often focused on 'nurture arguments regarding cognitive sex differences. In the current narrative review, we provide a comprehensive overview regarding the origins and historical advancement of these debates while providing a summary of the results in the field of sexually polymorphic cognition. In so doing, we attempt to highlight the importance of using transdisciplinary perspectives which help bridge disciplines together to provide a refined understanding the specific factors that drive sex differences a gender diversity in cognitive abilities. To summarize, biological sex (e.g., birth-assigned sex, sex hormones), socio-cultural gender (gender identity, gender roles), and sexual orientation each uniquely shape the cognitive abilities reviewed. To date, however, few studies integrate these sex and gender factors together to better understand individual differences in cognitive functioning. This has potential benefits if a broader understanding of sex and gender factors are systematically measured when researching and treating numerous conditions where cognition is altered.

No Support for Two Hypotheses About the Communicative Functions of Displaying Disgust: Evidence From Turkey, Norway, Germany, and Croatia

In recent years, researchers have discovered much about how disgust works, its neural basis, its relationship with immune function, its connection with mating, and some of its antecedents and consequents. Despite these advances in our understanding, an under-explored area is how disgust may be used to serve a communicative function, including how individuals might strategically downplay or exaggerate the disgust display in front of different audiences. Here, we generated two hypotheses about potential communicative functions of disgust, and tested these hypotheses in four countries (Turkey, Croatia, Germany, and Norway). We found no evidence in support of either hypothesis in any country. Discussion focuses on the likely falsity of the two central hypotheses, alternative interpretations of our findings, and directions for future research.

Articulatory effects on perceptions of men's status and attractiveness

Research on heterosexual mating has demonstrated that acoustic parameters (e.g., pitch) of men's voices influence their attractiveness to women and appearance of status and formidability to other men. However, little is known about how men's tendency to clearly articulate their speech influences these important social perceptions. In the current study, we used a repeated-measures design to investigate how men's articulatory clarity or conformity influenced women's (N = 45) evaluations of men's attractiveness for both short- and long-term relationships, and men's (N = 46) evaluations of physical formidability and prestige. Results largely supported our hypotheses: men who enunciated phonemes more distinctly were more attractive to women for long-term relationships than short-term relationships and were perceived by other men to have higher prestige than physical dominance. These findings suggest that aspects of articulatory behavior that influence perceptions of prestige and long-term mating attractiveness may indicate an early social history characterized by high socioeconomic status, likely owing to crystallization of articulatory patterns during the critical period of language development. These articulatory patterns may also be honest signals of condition or disposition owing to the nature of complex, multicomponent traits, which deserve further empirical attention.

The sexual selection of creativity: A nomological approach

Cultural innovations, such as tools and other technical articles useful for survival, imply that creativity is an outcome of evolution. However, the existence of purely ornamental items obfuscates the functional value of creativity. What is the functional or adaptive value of aesthetic and intellectual ornaments? Recent evidence shows a connection between ornamental creativity, an individual's attractiveness, and their reproductive success. However, this association is not sufficient for establishing that creativity in humans evolved by sexual selection. In this critical review, we synthesize findings from many disciplines about the mechanisms, ontogeny, phylogeny, and the function of creativity in sexual selection. Existing research indicates that creativity has the characteristics expected of a trait evolved by sexual selection: genetic basis, sexual dimorphism, wider variety in males, influence of sex hormones, dysfunctional expressions, an advantage in mating in humans and other animals, and psychological modules adapted to mating contexts. Future studies should investigate mixed findings in the existing literature, such as creativity not being found particularly attractive in a non-WEIRD society. Moreover, we identified remaining knowledge gaps and recommend that further research should be undertaken in the following areas: sexual and reproductive correlates of creativity in non-WEIRD societies, relationship between androgens, development, and creative expression, as well as the impact of ornamental, technical and everyday creativity on attractiveness. Evolutionary research should analyze whether being an evolved signal of genetic quality is the only way in which creativity becomes sexually selected and therefore passed on from generation to generation. This review has gone a long way toward integrating and enhancing our understanding of ornamental creativity as a possible sexual selected psychological trait.

Why do family firms dismiss their family CEOs? A perspective on kinship ties

Existing studies have suggested that nonfamily CEOs are more likely to be fired from family firms, while we focus on why family CEOs are also fired from family firms. Using data from 455 listed Chinese family firms, we find that family CEOs with affinity ties are more likely to be dismissed as they are not genetically related to the family. The difference becomes greater when firm performance is poor or family ownership is high. These findings elaborate that business-owing family is not a group with aligned interests, that is, family members with different family identities are treated differently within family. Besides, existing studies have emphasized that the preservation of socioemotional wealth in family firms can affect firms' operations, while this study further proposes that the preservation of socioemotional wealth can also have an impact on the business-owning families themselves.

Regional culture: The role of the invisible hand in shaping local family firms’ top management team

Research on family businesses has focused on the differences between family and non-family firms regarding the top management team (TMT), while this study further explores the difference within family firms from different regional culture based on the perspective of socio-emotional wealth (SEW) and evolutionary psychology. Using a sample comprised of all 625 family firms listed on the Small & Medium Enterprise Board and Growth Enterprise Board in Shenzhen Stock Exchange, this study finds that in regions of strong clan culture, family members are more willing to be involved in a family business and accept lower economic rewards. Particularly, when financial risk is high, these relationships mentioned above become more significant. Based on the results, this study proves that regional culture can affect the characteristics of top management teams in family firms, explains the heterogeneity of family firms’ decision-making from a culture-based perspective and extends existing research on family business from the level of “family firm vs. non-family firm” to that of “family firms affected by different regional cultures”.

Empowerment Mitigates Gender Differences in Tertius Iungens Brokering

Tertius iungens brokering that brings together people who might not otherwise meet is crucial for organizational effectiveness. But we know little about whether and why women and men differ in their propensity to engage in this brokering. Our paper focuses on the origins and mitigation of gender differences in the propensity to bring people together. In study 1, we showed that the Totterdell et al. [Totterdell P, Holman D, Hukin A (2008) Social networkers: Measuring and examining individual differences in propensity to connect with others. Soc. Networks 30(4):283–296] propensity-to-join-others scale that we used in study 2 and the Obstfeld [Obstfeld D (2005) Social networks, the tertius iungens orientation, and involvement in innovation. Admin. Sci. Quart. 50(1):100–130] tertius iungens scale overlapped not only conceptually, but also empirically, and that these measures of tertius iungens were distinct from mediation- and separation-brokering propensities [Grosser TJ, Obstfeld D, Labianca G, Borgatti SP (2019) Measuring mediation and separation brokerage orientations: A further step toward studying the social network brokerage process. Acad. Management Discoveries 5(2):114–136]. In study 2, we used a natural experiment to examine the tertius iungens brokering propensities of 876 identical and 625 fraternal same-sex twins. We found that brokering propensity was lower for women than for men, although the propensity toward sociability in terms of making friends and acquaintances was lower for men. We also found that for women, relative to men, tertius iungens brokering propensity was largely affected by environmental influences, such as the experience of stereotyping and discrimination, rather than representing an inherited disposition. Moreover, the differences between men and women with respect to brokering were mitigated for empowered samples, such as well-educated or entrepreneurial individuals. Our research asks new questions about how environmental pressures and empowerment affect social networking. Gender differences in brokering may be amenable to mitigation through empowering practices that include education and entrepreneurial experience.

Clinical effectiveness of an integrative psychotherapy technique for the treatment of trauma: A phase I investigation of Heart Assisted Therapy

There is a need for more effective clinical interventions to assist individuals in healing from lingering negative and traumatic experiences. Furthermore, healing from such experiences and coping with residual symptoms are conceptionally separate yet important outcomes in psychotherapy. This report describes a Phase I investigation that evaluates an innovative integrative psychotherapy technique that promotes healing in addition to providing a method of coping while treatment is in progress. 43 patients were treated by 2 separate psychologists using Heart Assisted Therapy (HAT) in their private practices. There was a total of 81 specific upsetting and/or traumatic life events treated. All patients completed a standardized form to rate their degree of distress before and after HAT for each life event. Follow-up data were also collected ranging from 3 months to over 18 months post-treatment. Data analysis revealed the average number of HAT sessions for a treated incident was 3 - 4. The mean distress level was 7.55 before HAT and 0.00 after HAT for an exploratory study (n=13; p < .0000001), and 8.31 before HAT and 0.02 after HAT for a confirmatory study (n = 30; p < .0000001). These improvements were replicated across therapists, gender, and veteran status. The combined findings suggest that the integrative Heart Assisted Therapy model has important practical as well as theoretical significance. Future Phase II and Phase III studies can be performed to confirm the large magnitude of the patients perceived clinical effects and evaluate potential moderating variables such as expectancy.

The Evolution of Playfulness, Play and Play-Like Phenomena in Relation to Sexual Selection

By conceptualizing Sexual Selection, Darwin showed a way to analyze intra-specific individual differences within an evolutionary perspective. Interestingly, Sexual Selection is often used to investigate the origins of sports, arts, humor, religion and other phenomena that, in several languages, are simply called "play." Despite their manifested differences, these phenomena rely on shared psychological processes, including playfulness. Further, in such behaviors there is usually considerable individual variability, including sex differences, and positive relationship with mating success. However, Sexual Selection is rarely applied in the study of play, with exception to what is concerned as infant training behavior for adult sex roles. We offer an integrated grounding of playful phenomena aligning evolutionary propositions based on sexual selection, which might stimulate further exploration of playfulness within evolutionary perspective.

What is the expected human childhood? Insights from evolutionary anthropology

In psychological research, there are often assumptions about the conditions that children expect to encounter during their development. These assumptions shape prevailing ideas about the experiences that children are capable of adjusting to, and whether their responses are viewed as impairments or adaptations. Specifically, the expected childhood is often depicted as nurturing and safe, and characterized by high levels of caregiver investment. Here, we synthesize evidence from history, anthropology, and primatology to challenge this view. We integrate the findings of systematic reviews, meta-analyses, and cross-cultural investigations on three forms of threat (infanticide, violent conflict, and predation) and three forms of deprivation (social, cognitive, and nutritional) that children have faced throughout human evolution. Our results show that mean levels of threat and deprivation were higher than is typical in industrialized societies, and that our species has experienced much variation in the levels of these adversities across space and time. These conditions likely favored a high degree of phenotypic plasticity, or the ability to tailor development to different conditions. This body of evidence has implications for recognizing developmental adaptations to adversity, for cultural variation in responses to adverse experiences, and for definitions of adversity and deprivation as deviation from the expected human childhood.

Human spatial memory is biased towards high-calorie foods: a cross-cultural online experiment

Background

Human memory appears to prioritise locations of high-calorie foods, likely as an adaptation for foraging within fluctuating ancestral food environments. Importantly, this “high-calorie bias” in human spatial memory seems to yield consequences for individual eating behaviour in modern food-abundant settings. However, as studies have mainly been conducted in European (Dutch) populations to date, we investigated whether the existence of the cognitive bias can be reasonably generalised across countries that vary on culturally-relevant domains, such as that of the USA and Japan. Furthermore, we investigated whether sociodemographic factors moderate the expression of the high-calorie spatial memory bias in different populations.

Methods

In a cross-cultural online experiment, we measured the food location memory of diverse participants from the USA (N = 72; 44.4% Male; 54 ± 15.99 years) and Japan (N = 74; 56.8% Male; 50.85 ± 17.32 years), using a validated computer-based spatial memory task with standardised images of high-calorie and low-calorie foods. To directly compare the magnitude of the high-calorie spatial memory bias in a broader cultural scope, we also included data from a previous online experiment that identically tested the food spatial memory of a Dutch sample (N = 405; 56.7% Male; 47.57 ± 17.48 years).

Results

In the US sample, individuals more accurately recalled (i.e. had lower pointing errors for) locations of high-calorie foods versus that of low-calorie alternatives (Mean difference = -99.23 pixels, 95% CI = [-197.19, -1.28]) – regardless of one’s hedonic preferences, familiarity with foods, and encoding times. Likewise, individuals in the Japanese sample displayed an enhanced memory for locations of high-calorie (savoury-tasting) foods (Mean difference = -40.41 pixels, 95% CI = [-76.14, -4.68]), while controlling for the same set of potential confounders. The magnitude of the high-calorie bias in spatial memory was similar across populations (i.e. the USA, Japan, and the Netherlands), as well as across diverse sociodemographic groups within a population.

Conclusions

Our results demonstrate that the high-calorie bias in spatial memory transcends sociocultural boundaries. Since the cognitive bias may negatively impact on our dietary decisions, it would be wise to invest in strategies that intervene on our seemingly universal ability to efficiently locate calorie-rich foods.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-022-01252-w.

Why Evolutionary Psychology Should Abandon Modularity

A debate surrounding modularity-the notion that the mind may be exclusively composed of distinct systems or modules-has held philosophers and psychologists captive for nearly 40 years. Concern about this thesis-which has come to be known as the massive modularity debate-serves as the primary grounds for skepticism of evolutionary psychology's claims about the mind. In this article we argue that the entirety of this debate, and the very notion of massive modularity itself, is ill-posed and confused. In particular, it is based on a confusion about the level of analysis (or reduction) at which one is approaching the mind. Here we provide a framework for clarifying at what level of analysis one is approaching the mind and explain how a systemic failure to distinguish between different levels of analysis has led to profound misunderstandings of not only evolutionary psychology but also of the entire cognitivist enterprise of approaching the mind at the level of the mechanism. We furthermore suggest that confusions between different levels of analysis are endemic throughout the psychological sciences-extending well beyond issues of modularity and evolutionary psychology. Therefore, researchers in all areas should take preventive measures to avoid this confusion in the future.

Why Do People (Not) Engage in Social Distancing? Proximate and Ultimate Analyses of Norm-Following During the COVID-19 Pandemic

COVID-19 has had a profound negative effect on many aspects of human life. While pharmacological solutions are being developed and implemented, the onus of mitigating the impact of the virus falls, in part, on individual citizens and their adherence to public health guidelines. However, promoting adherence to these guidelines has proven challenging. There is a pressing need to understand the factors that influence people's adherence to these guidelines in order to improve public compliance. To this end, the current study investigated whether people's perceptions of others' adherence predict their own adherence. We also investigated whether any influence of perceived social norms was mediated by perceptions of the moral wrongness of non-adherence, anticipated shame for non-adherence, or perceptions of disease severity. One hundred fifty-two Australians participated in our study between June 6, 2020 and August 21, 2020. Findings from this preliminary investigation suggest that (1) people match their behavior to perceived social norms, and (2) this is driven, at least in part, by people using others' behavior as a cue to the severity of disease threat. Such findings provide insight into the proximate and ultimate bases of norm-following behavior, and shed preliminary light on public health-related behavior in the context of a pandemic. Although further research is needed, the results of this study-which suggest that people use others' behavior as a cue to how serious the pandemic is and as a guide for their own behavior-could have important implications for public health organizations, social movements, and political leaders and the role they play in the fight against epidemics and pandemics.

Are Emotions Natural Kinds After All? Rethinking the Issue of Response Coherence

The synchronized co-activation of multiple responses-motivational, behavioral, and physiological-has been taken as a defining feature of emotion. Such response coherence has been observed inconsistently however, and this has led some to view emotion programs as lacking biological reality. Yet, response coherence is not always expected or desirable if an emotion program is to carry out its adaptive function. Rather, the hallmark of emotion is the capacity to orchestrate multiple mechanisms adaptively-responses will co-activate in stereotypical fashion or not depending on how the emotion orchestrator interacts with the situation. Nevertheless, might responses cohere in the general case where input variables are specified minimally? Here we focus on shame as a case study. We measure participants' responses regarding each of 27 socially devalued actions and personal characteristics. We observe internal and external coherence: The intensities of felt shame and of various motivations of shame (hiding, lying, destroying evidence, and threatening witnesses) vary in proportion (i) to one another, and (ii) to the degree to which audiences devalue the disgraced individual-the threat shame defends against. These responses cohere both within and between the United States and India. Further, alternative explanations involving the low-level variable of arousal do not seem to account for these results, suggesting that coherence is imparted by a shame system. These findings indicate that coherence can be observed at multiple levels and raise the possibility that emotion programs orchestrate responses, even in those situations where coherence is low.

Pandemic Leadership: Sex Differences and Their Evolutionary-Developmental Origins

The COVID-19 pandemic has caused a global societal, economic, and social upheaval unseen in living memory. There have been substantial cross-national differences in the kinds of policies implemented by political decision-makers to prevent the spread of the virus, to test the population, and to manage infected patients. Among other factors, these policies vary with politicians' sex: early findings indicate that, on average, female leaders seem more focused on minimizing direct human suffering caused by the SARS-CoV-2 virus, while male leaders implement riskier short-term decisions, possibly aiming to minimize economic disruptions. These sex differences are consistent with broader findings in psychology, reflecting women's stronger empathy, higher pathogen disgust, health concern, care-taking orientation, and dislike for the suffering of other people-as well as men's higher risk-taking, Machiavellianism, psychopathy, narcissism, and focus on financial indicators of success and status. This review article contextualizes sex differences in pandemic leadership in an evolutionary framework. Evolution by natural selection is the only known process in nature that organizes organisms into higher degrees of functional order, or counteracts the unavoidable disorder that would otherwise ensue, and is therefore essential for explaining the origins of human sex differences. Differential sexual selection and parental investment between males and females, together with the sexual differentiation of the mammalian brain, drive sex differences in cognition and behavioral dispositions, underlying men's and women's leadership styles and decision-making during a global pandemic. According to the sexually dimorphic leadership specialization hypothesis, general psychobehavioral sex differences have been exapted during human evolution to create sexually dimorphic leadership styles. They may be facultatively co-opted by societies and/or followers when facing different kinds of ecological and/or sociopolitical threats, such as disease outbreaks or intergroup aggression. Early evidence indicates that against the invisible viral foe that can bring nations to their knees, the strategic circumspection of empathic feminine health "worriers" may bring more effective and humanitarian outcomes than the devil-may-care incaution of masculine risk-taking "warriors".

The correct way to test the hypothesis that racial categorization is a byproduct of an evolved alliance-tracking capacity

The project of identifying the cognitive mechanisms or information-processing functions that cause people to categorize others by their race is one of the longest-standing and socially-impactful scientific issues in all of the behavioral sciences. This paper addresses a critical issue with one of the few hypotheses in this area that has thus far been successful-the alliance hypothesis of race-which had predicted a set of experimental circumstances that appeared to selectively target and modify people's implicit categorization of others by their race. Here, we will show why the evidence put forward in favor of this hypothesis was not in fact evidence in support of the hypothesis, contrary to common understanding. We will then provide the necessary and crucial tests of the hypothesis in the context of conflictual alliances, determining if the predictions of the alliance hypothesis of racial categorization in fact hold up to experimental scrutiny. When adequately tested, we find that indeed categorization by race is selectively reduced when crossed with membership in antagonistic alliances-the very pattern predicted by the alliance hypothesis. This finding provides direct experimental evidence that the human mind treats race as proxy for alliance membership, implying that racial categorization does not reflect attention to physical features per se, but rather to social relationships.

An Experimental Examination of Demand-Side Preferences for Female and Male National Leaders

Females constitute a far smaller proportion of political leaders than their proportion in the general population. Leading demand- and supply side explanations for this phenomenon account for some of the variance but leave a great deal unexplained. In an effort to account for additional variance, this research evaluates the issue informed by the biological theory of evolution by natural selection, a foundational explanation for the diversity and function of living organisms. It experimentally assesses how varying types of inter- and intragroup threat-a recurring ancestral problem-affect demand for female and male national leaders. This work analyzes data collected from individuals (N = 826) in the U.S. during the 2012 Cooperative Congressional Election Study. The results suggest the predominant preference for male over female leaders in some contexts may be the non-adaptive and non-functional but lingering outcome of an adaptive preference for physically formidable allies that was shaped by natural selection in ancestral environments.

Individuals with Psychopathic Traits and Poor Attitudes towards Animals Can Recognise Infant Features But Give Them Reduced Attentional Priority

Simple Summary

Certain facial characteristics in companion animals are perceived by humans as being ‘cute’. This includes having large eyes, a round head and a small nose and mouth. These characteristics, which are shared with human infants, trigger care-giving responses in humans. Despite this, however, companion animal abuse occurs. The aim of this research was to better understand cognitive processes of people with pro-social personality traits and positive attitudes towards animals compared to those with anti-social personality traits and negative attitudes towards animals. This was done by assessing participants’ ability to detect cues of cuteness in animal and human infant faces (study 1) and by assessing attention to cuteness cues via an eye-tracking task (study 2). Findings indicate that the ability to detect cuteness cues is widespread, regardless of personality or attitudes. However, individuals with anti-social personality traits and negative attitudes towards animals chose to pay less attention to ‘cute’ stimuli in the eye-tracking task. This proof of concept study is an initial step in determining how individuals ‘at risk’ of committing animal abuse process information on infant features in animals.

Abstract

Infant features are physical traits that are characteristic of human infants and include facial features such as large and low-lying eyes, and a small nose and mouth. Animals possessing high levels of infant features elicit care-giving responses in humans. Despite this, animal cruelty is a common occurrence. The aim of this research was to determine whether the ability to recognise and/or attend to infant features is linked to subclinical psychopathic traits and attitudes towards animals. Using a community sample, participants (n = 387) completed a cuteness forced-choice task. Self-reported psychopathy and attitude towards animals were not related to the participants’ ability to detect cues of cuteness in human infants and animals. In a second study, participants (n = 142) were screened for low versus high primary psychopathy and low versus high animal attitude scores. A Psychopathy-Attitude Composite score was created and a subset of participants (n = 50) from the upper and lower quartiles completed a free-viewing eye-tracking task where ‘Cute’, ‘Neutral, ‘Monetary’ and ‘Control’ images were presented in pairs. Higher levels of psychopathic traits and an anti-animal welfare attitude were associated with decreased attention to ‘Cute’ images in terms of decreased dwell time, mean fixation duration and mean fixation count, measures of voluntary attention. There were a number of interactions between Psychopathy-Attitude Composite classification and attention to each image category in terms of dwell time, first fixation duration, mean fixation duration and fixation count. These findings support the theory that individuals with psychopathic traits recognise facial cues of vulnerability but choose to give them reduced attentional priority. This may have implications for animal welfare.

Evolutionary Mismatch in Mating

Evolutionary mismatch concepts are being fruitfully employed in a number of research domains, including medicine, health, and human cognition and behavior to generate novel hypotheses and better understand existing findings. We contend that research on human mating will benefit from explicitly addressing both the evolutionary mismatch of the people we study and the evolutionary mismatch of people conducting the research. We identified nine mismatch characteristics important to the study of human mating and reviewed the literature related to each of these characteristics. Many of the people we study are: exposed to social media, in temporary relationships, relocatable, autonomous in their mating decisions, nulliparous, in groups that are socially segmented, in an educational setting, confronted with lots of options, and young. We applied mismatch concepts to each characteristic to illustrate the importance of incorporating mismatch into this research area. Our aim in this paper is not to identify all potential mismatch effects in mating research, nor to challenge or disqualify existing data. Rather, we demonstrate principled ways of thinking about evolutionary mismatch in order to propel progress in mating research. We show how attending to the potential effects of mismatch can help us refine our theoretical and methodological approaches and deepen our understanding of existing patterns in the empirical record. We conclude with specific recommendations about how to include consideration of evolutionary mismatch into research on human mating.

Eating Disorders: An Evolutionary Psychoneuroimmunological Approach

Eating disorders are evolutionarily novel conditions. They lead to some of the highest mortality rates of all psychiatric disorders. Several evolutionary hypotheses have been proposed for eating disorders, but only the intrasexual competition hypothesis is extensively supported by evidence. We present the mismatch hypothesis as a necessary extension to the current theoretical framework of eating disorders. This hypothesis explains the evolutionarily novel adaptive metaproblem that has arisen when mating motives conflict with the large-scale and easy availability of hyper-rewarding but obesogenic foods. This situation is exacerbated particularly in those contemporary environments that are characterized by sedentary lifestyles, ever-present junk foods, caloric surplus and the ubiquity of social comparisons that take place via social media. Our psychoneuroimmunological model connects ultimate-level causation with proximate mechanisms by showing how the adaptive metaproblem between mating motives and food rewards leads to chronic stress and, further, to disordered eating. Chronic stress causes neuroinflammation, which increases susceptibility to OCD-like behaviors that typically co-occur with eating disorders. Chronic stress upregulates the serotonergic system and causes dysphoric mood in anorexia nervosa patients. Dieting, however, reduces serotonin levels and dysphoric mood, leading to a vicious serotonergic-homeostatic stress/starvation cycle whereby cortisol and neuroinflammation increase through stringent dieting. Our psychoneuroimmunological model indicates that between-individual and within-individual variation in eating disorders partially arises from (co)variation in gut microbiota and stress responsivity, which influence neuroinflammation and the serotonergic system. We review the advances that have been made in recent years in understanding how to best treat eating disorders, outlining directions for future clinical research. Current evidence indicates that eating disorder treatments should aim to reduce the chronic stress, neuroinflammation, stress responsivity and gut dysbiosis that fuel the disorders. Connecting ultimate causes with proximate mechanisms and treating biopsychosocial causes rather than manifest symptoms is expected to bring more effective and sophisticated long-term interventions for the millions of people who suffer from eating disorders.

Investigating the interchangeability and clinical utility of MVPT-3 and MVPT-4 for 7-10 year children with and without specific learning disabilities

The aim of our study was to determine the sensitivity and specificity levels of MVPT-3 and MVPT-4 in 7-10 year children with specific learning disabilities (SLD) and to compare the clinical usability of these assessment tools. This study was designed as a case-controlled study. 96 ( study group = 48, control group = 48) 7-10 year children were included. The study occurred three stages. In the first place, MVPT-3 and MVPT-4 tests were examined with reference to the Core Outcome Set(COS) evaluation criteria. In the second step, the similarities and differences of MVPT-3 and MVPT-4 tests observed in clinical practices were examined by taking the feedback of experts. In the last step, in order to examine the sensitivity and specificity levels of the tests, assessments were performed in two groups with 1-week intervals. According to the COS results; MVPT-3 test was examined better than MVPT-4 test under cross-cultural validity title. The sensitivity and specificity of the MVPT-3 test were 0.68 and 0.77, and the sensitivity and specificity of MVPT-4 test were 0.50 and 0.87 respectively. This study will help clinicians working on children aged 7-10 to decide the type of test they will use to evaluate visual perception processes.

Get some respect - buy organic foods! When everyday consumer choices serve as prosocial status signaling

Status considerations have recently been linked to prosocial behaviors. This research shows that even everyday consumer behaviors such as favoring organic foods serve as prosocial status signaling. Key ideas from the continuum model of consumer impression formation and the theories of costly signaling and symbolic consumption are synthetized to make sense of this phenomenon. Two web-surveys (Ns = 187, 259) and a field study (N = 336) following experimental designs are conducted. This approach allows the analysis of both the more and less conscious reactions of consumers. Study 1 shows that the image of consumers favoring organic product versions is marked by characteristics consistent with prosocial status signaling. Study 2 replicates these findings with another sample and a wider range of products and demonstrate that observers' conservative values influence the image formed of organic food users. Study 3 establishes that similar image effects also emerge through a less conscious formation process and that they extend to how organic food users are socially treated. This research advances the current understanding concerning the interlinkages between organic food usage, prosocial status signaling, consumer impressions and reputation management. Substantively, the studies provide novel compelling empirical evidence for the ability of non-luxurious everyday consumer behaviors to qualify as prosocial status signaling. Conceptually, the integration of evolutionary and sociocultural perspectives represents a major contribution. More specifically, this research yields new understanding as regards the role of individual variation in sensing and interpreting status symbols.

Foundations of Arrogance: A Broad Survey and Framework for Research

We consider the topic of arrogance from a cross-disciplinary viewpoint. To stimulate further research, we suggest three types of arrogance (individual, comparative, and antagonistic) and six components contributing to them, each logically related to the next. The components progress from imperfect knowledge and abilities to an unrealistic assessment of them, an unwarranted attitude of superiority over other people, and related derisive behavior. Although each component presumably is present to some degree when the next one operates, causality might flow between components in either direction. The classification of components of arrogance should reduce miscommunication among researchers, as the relevant concepts and mechanisms span cognitive, motivational, social, and clinical domains and literatures. Arrogance is an important concept warranting further study for both theoretical and practical reasons, in both psychopathology and normal social interaction. Everyone seems to have qualities of arrogance to some degree, and we consider the importance of arrogance on a spectrum. We contend that humankind can benefit from a better understanding of the cognitive limitations and motivational biases that, operating together, appear to contribute to arrogance. We bring together information and questions that might lead to an invigorating increase in the rate and quality of cross-disciplinary research on arrogance.

Disease Threat and the Functional Flexibility of Ingroup Derogation

While the findings from previous studies directly relate the ingroup derogation phenomenon to the evolved response of the behavioral immune system, there are three major limitations in the previous studies on the functional flexibility of ingroup derogation. The present study further investigated the functional flexibility of ingroup derogation by conducting three behavioral experiments on Chinese participants. In Experiment 1, we tested whether exposing to situational disease primes leads to an exaggerated ingroup derogation attitude by adopting a more rigorous control. In Experiment 2, we manipulated the source of disease threats to test whether the ingroup derogation mechanism adjusts its response according to the specific perceived vulnerabilities to the disease threats posed by ingroup and outgroup members. In Experiment 3, we tested whether recent illness promotes the expression of ingroup derogation attitudes. Results of the three experiments consistently showed that, the Chinese participants adjusted their ingroup derogation attitudes according to the external environmental disease cues (Experiments 1 and 2) and the internal physiological disease cues (Experiment 3). The results also showed that the ingroup derogation mechanism was sensitive to the specific perceived vulnerabilities to the ingroup disease threat and the outgroup disease threat (Experiment 2). Taken together, these results support the evolutionary hypothesis of ingroup derogation and suggest that the ingroup derogation found in East Asian cultures could be accounted by a functionally flexible disease-avoidance mechanism.

A Life History Approach to the Female Sexual Orientation Spectrum: Evolution, Development, Causal Mechanisms, and Health

Women's capacity for sexual fluidity is at least as interesting a phenomenon from the point of view of evolutionary biology and behavioral endocrinology as exclusively homosexual orientation. Evolutionary hypotheses for female nonheterosexuality have failed to fully account for the existence of these different categories of nonheterosexual women, while also overlooking broader data on the causal mechanisms, physiology, ontogeny, and phylogeny of female nonheterosexuality. We review the evolutionary-developmental origins of various phenotypes in the female sexual orientation spectrum using the synergistic approach of Tinbergen's four questions. We also present femme-specific and butch-specific hypotheses at proximate and ultimate levels of analysis. This review article indicates that various nonheterosexual female phenotypes emerge from and contribute to hormonally mediated fast life history strategies. Life history theory provides a biobehavioral explanatory framework for nonheterosexual women's masculinized body morphology, psychological dispositions, and their elevated likelihood of experiencing violence, substance use, obesity, teenage pregnancy, and lower general health. This pattern of life outcomes can create a feedback loop of environmental unpredictability and harshness which destabilizes intrauterine hormonal conditions in mothers, leading to a greater likelihood of fast life history strategies, global health problems, and nonheterosexual preferences in female offspring. We further explore the potential of female nonheterosexuality to function as an alloparental buffer that enables masculinizing alleles to execute their characteristic fast life history strategies as they appear in the female and the male phenotype. Synthesizing life history theory with the female sexual orientation spectrum enriches existing scientific knowledge on the evolutionary-developmental mechanisms of human sex differences.

Evolutionary psychology meets socio-ecological psychology: the motivational psychologies of disease-avoidance and parental care

Specific features of ancestral ecologies had implications for the evolution of psychological mechanisms that regulate specific aspects of human cognition and behavior within contemporary ecologies. These mechanisms produce predictably different attitudes, judgments and behavioral dispositions under different circumstances. This article summarizes two illustrative programs of research-one that focuses on the evolved psychology of disease-avoidance and its many implications, and the other that focuses on the evolved psychology of parental care-giving and its many implications. These programs of research exemplify the generative utility of evolutionary psychological conceptual methods within the domain of socio-ecological psychology.

Smartphones and Close Relationships: The Case for an Evolutionary Mismatch

This article introduces and outlines the case for an evolutionary mismatch between smartphones and the social behaviors that help form and maintain close social relationships. As psychological adaptations that enhance human survival and inclusive fitness, self-disclosure and responsiveness evolved in the context of small kin networks to facilitate social bonds, promote trust, and enhance cooperation. These adaptations are central to the development of attachment bonds, and attachment theory is a middle-level evolutionary theory that provides a robust account of the ways human bonding provides for reproductive and inclusive fitness. Evolutionary mismatches operate when modern contexts cue ancestral adaptations in a manner that does not provide for their adaptive benefits. We argue that smartphones and their affordances, although highly beneficial in many circumstances, cue humans’ evolved needs for self-disclosure and responsiveness across broad virtual networks and, in turn, have the potential to undermine immediate interpersonal interactions. We review emerging evidence on the topic of technoference, which is defined as the ways in which smartphone use may interfere with or intrude into everyday social interactions. The article concludes with an empirical agenda for advancing the integrative study of smartphones, intimacy processes, and close relationships.

What we (should) talk about when we talk about fruitfulness

What are the relevant values to the appraisal of research programs? This question remains hotly debated, as philosophers have recently proposed many lists of values potentially relevant to scientific appraisal. Surprisingly, despite being mentioned in many lists, little attention has been paid to fruitfulness. It is unclear how fruitfulness should be explicated, and whether it has any substantial role in scientific appraisal. In this paper, I argue we should explicate fruitfulness as the capacity to develop of research programs. Moreover, I provide a novel strategy to assess and compare the fruitfulness of programs focused on their research questions and heuristics. To illustrate how this strategy would work, I will discuss a case study, namely the adaptationist program in evolutionary psychology.

A field guide for teaching evolution in the social sciences

The theory of evolution by natural selection has begun to revolutionize our understanding of perception, cognition, language, social behavior, and cultural practices. Despite the centrality of evolutionary theory to the social sciences, many students, teachers, and even scientists struggle to understand how natural selection works. Our goal is to provide a field guide for social scientists on teaching evolution, based on research in cognitive psychology, developmental psychology, and education. We synthesize what is known about the psychological obstacles to understanding evolution, methods for assessing evolution understanding, and pedagogical strategies for improving evolution understanding. We review what is known about teaching evolution about nonhuman species and then explore implications of these findings for the teaching of evolution about humans. By leveraging our knowledge of how to teach evolution in general, we hope to motivate and equip social scientists to begin teaching evolution in the context of their own field.

Depression subtyping based on evolutionary psychiatry: Proximate mechanisms and ultimate functions

Major depressive disorder constitutes one of the leading causes of disability worldwide. However, it is not a unitary disease-it is a heterogeneous syndrome, with patients differing remarkably in symptom profile, pathophysiology and treatment responsiveness. Previous attempts to subtype major depressive disorder have showed limited clinical applicability. We present a classification of major depressive disorder episodes based on the proximate mechanisms that led to the original mood change that caused the depressive episode. We identify discrete depression subtypes that are induced by: 1) infection, 2) long-term stress, 3) loneliness, 4) traumatic experience, 5) hierarchy conflict, 6) grief, 7) romantic rejection, 8) postpartum events, 9) the season, 10) chemicals, 11) somatic diseases and 12) starvation. We further examine the ultimate functions of these subtypes and show that not all types of mood changes that trigger depression are adaptive. Instead, some are clearly maladaptive and some are byproducts of other adaptations. In modern societies, low mood after adverse life events may turn into a pathological depressive state. Modern lifestyle increases susceptibility to inflammatory dysregulation and chronic stress, both of which increase the amount of proinflammatory cytokines in peripheral blood, leading to low mood and sickness behaviour. Proinflammatory cytokines may aggravate the previously adaptive short-term mood changes to a chronic maladaptive depressive state by preventing the normalization of mood after adverse life events. Subtyping depression enables an effective and intelligent long-term treatment of patients in each subtype by treating the underlying causes of depression.

The "appropriate" response to deprivation: Evolutionary and ethical dimensions

Pepper & Nettle use an evolutionary framework to argue that "temporal discounting" is an appropriate response to low socioeconomic status (SES), or deprivation. We suggest some conceptual refinements to their "appropriate-response" perspective, with the hope that it usefully informs future research on and public policy responses to the relationship between deprivation and temporal discounting.

Contemporary evolutionary psychology and the evolution of intelligence

Burkart et al.'s impressive synthesis will serve as a valuable resource for intelligence research. Despite its strengths, the target article falls short of offering compelling explanations for the evolution of intelligence. Here, we outline its shortcomings, illustrate how these can lead to misguided conclusions about the evolution of intelligence, and suggest ways to address the article's key questions.

Why Women Wear High Heels: Evolution, Lumbar Curvature, and Attractiveness

Despite the widespread use of high-heeled footwear in both developing and modernized societies, we lack an understanding of this behavioral phenomenon at both proximate and distal levels of explanation. The current manuscript advances and tests a novel, evolutionarily anchored hypothesis for why women wear high heels, and provides convergent support for this hypothesis across multiple methods. Using a recently discovered evolved mate preference, we hypothesized that high heels influence women's attractiveness via effects on their lumbar curvature. Independent studies that employed distinct methods, eliminated multiple confounds, and ruled out alternative explanations showed that when women wear high heels, their lumbar curvature increased and they were perceived as more attractive. Closer analysis revealed an even more precise pattern aligning with human evolved psychology: high-heeled footwear increased women's attractiveness only when wearing heels altered their lumbar curvature to be closer to an evolutionarily optimal angle. These findings illustrate how human evolved psychology can contribute to and intersect with aspects of cultural evolution, highlighting that the two are not independent or autonomous processes but rather are deeply intertwined.