Parasite stress and pathogen avoidance relate to distinct dimensions of political ideology across 30 nations.

People who are more avoidant of pathogens are more politically conservative, as are nations with greater parasite stress. In the current research, we test two prominent hypotheses that have been proposed as explanations for these relationships. The first, which is an intragroup account, holds that these relationships between pathogens and politics are based on motivations to adhere to local norms, which are sometimes shaped by cultural evolution to have pathogen-neutralizing properties. The second, which is an intergroup account, holds that these same relationships are based on motivations to avoid contact with outgroups, who might pose greater infectious disease threats than ingroup members. Results from a study surveying 11,501 participants across 30 nations are more consistent with the intragroup account than with the intergroup account. National parasite stress relates to traditionalism (an aspect of conservatism especially related to adherence to group norms) but not to social dominance orientation (SDO; an aspect of conservatism especially related to endorsements of intergroup barriers and negativity toward ethnic and racial outgroups). Further, individual differences in pathogen-avoidance motives (i.e., disgust sensitivity) relate more strongly to traditionalism than to SDO within the 30 nations.

Why (and When) Straight Women Trust Gay Men: Ulterior Mating Motives and Female Competition.

Previous findings indicate that heterosexual women experience a greater sense of comfort and trust in their friendships with gay men than in their friendships with heterosexual individuals. In the present studies, we tested a hypothesis that not only explains why women exhibit increased trust in gay men but also yields novel predictions about when (i.e., in what contexts) this phenomenon is likely to occur. Specifically, we propose that gay men's lack of motives to mate with women or to compete with them for mates enhances women's trust in gay men and openness to befriend them. Study 1 demonstrated that women placed greater trust in a gay man's mating-but not non-mating (e.g., career) advice-than in the same advice given by heterosexual individuals. Study 2 showed that women perceived a gay man to be more sincere in scenarios relevant to sexual and competitive mating deception. In Study 3, exposing women to a visualization of increased mating competition enhanced their trust in gay men; when mating competition was salient, women's trust in mating information from a gay man was amplified. Study 4 showed that women who perceived higher levels of mating competition were more open to befriending gay men. Together, these converging findings support our central hypothesis, which not only provides a distal explanation for the trust that straight women place in gay men, but also provides novel insights into previously unidentified contexts that facilitate the formation and strengthening of this unique bond.

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.

Mating strategy, disgust, and food neophobia.

Food neophobia and disgust are commonly thought to be linked, but this hypothesis is typically implicitly assumed rather than directly tested. Evidence for the connection has been based on conceptually and empirically unsound measures of disgust, unpublished research, and indirect findings. This study (N = 283) provides the first direct evidence of a relationship between trait-level food neophobia and trait-level pathogen disgust. Unexpectedly, we also found that food neophobia varies as a function of sexual disgust and is linked to mating strategy. Using an evolutionary framework, we propose a novel hypothesis that may account for these previously undiscovered findings: the food neophilia as mating display hypothesis. Our discussion centers on future research directions for discriminatively testing this novel hypothesis.

Cognitive and neuroscientific perspectives of healthy ageing.

With dementia incidence projected to escalate significantly within the next 25 years, the United Nations declared 2021-2030 the Decade of Healthy Ageing, emphasising cognition as a crucial element. As a leading discipline in cognition and ageing research, psychology is well-equipped to offer insights for translational research, clinical practice, and policy-making. In this comprehensive review, we discuss the current state of knowledge on age-related changes in cognition and psychological health. We discuss cognitive changes during ageing, including (a) heterogeneity in the rate, trajectory, and characteristics of decline experienced by older adults, (b) the role of cognitive reserve in age-related cognitive decline, and (c) the potential for cognitive training to slow this decline. We also examine ageing and cognition through multiple theoretical perspectives. We highlight critical unresolved issues, such as the disparate implications of subjective versus objective measures of cognitive decline and the insufficient evaluation of cognitive training programs. We suggest future research directions, and emphasise interdisciplinary collaboration to create a more comprehensive understanding of the factors that modulate cognitive ageing.

Evidence that the aesthetic preference for Hogarth's Line of Beauty is an evolutionary by-product.

In 1753, artist William Hogarth declared a specific S-shaped line to be the 'Line of Beauty' (LoB). Hogarth's assertion has had a profound impact on diverse fields over the past two and a half centuries. However, only one recent (2022) study has investigated whether Hogarth's assertion accurately captures humans' actual aesthetic preferences, and no research has explored why people find the LoB beautiful. We conducted two studies testing the hypothesis that the LoB's perceived beauty is an incidental by-product of cognitive systems that evolved to attend to fitness-relevant morphological features in people. In Study 1, we replicated the finding that female bodies whose lumbar curvature approximates the biomechanical optimum for dealing with the exigencies of pregnancy are rated as more attractive. In Study 2, we found that abstract lines extracted from these bodies were perceived as more beautiful than other lines. These results suggest that the preference for Hogarth's LoB is an incidental by-product of psychological mechanisms that evolved for other purposes. More broadly, these findings suggest that an evolutionary psychological approach - in particular the concept of evolutionary by-product - may be useful for understanding, explaining, and predicting people's aesthetic preferences for certain abstract symbols, which otherwise might seem arbitrary and inexplicable.

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.

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.

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.

Evolutionary psychology: A how-to guide.

Researchers in the social and behavioral sciences are increasingly using evolutionary insights to test novel hypotheses about human psychology. Because evolutionary perspectives are relatively new to psychology and most researchers do not receive formal training in this endeavor, there remains ambiguity about "best practices" for implementing evolutionary principles. This article provides researchers with a practical guide for using evolutionary perspectives in their research programs and for avoiding common pitfalls in doing so. We outline essential elements of an evolutionarily informed research program at 3 central phases: (a) generating testable hypotheses, (b) testing empirical predictions, and (c) interpreting results. We elaborate key conceptual tools, including task analysis, psychological mechanisms, design features, universality, and cost-benefit analysis. Researchers can use these tools to generate hypotheses about universal psychological mechanisms, social and cultural inputs that amplify or attenuate the activation of these mechanisms, and cross-culturally variable behavior that these mechanisms can produce. We hope that this guide inspires theoretically and methodologically rigorous research that more cogently integrates knowledge from the psychological and life sciences. (PsycINFO Database Record

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.

Friends with benefits: the evolved psychology of same- and opposite-sex friendship.

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.

Trade-offs, individual differences, and misunderstandings about evolutionary psychology.

Replies to comments on Evolutionary psychology: Controversies, questions, prospects, and limitations (see record 2010-02208-001) by Confer et al. The purpose of which was to clarify the logic of evolutionary psychology and clear up some of the more common misunderstandings about it. In this response, we address the key points raised by the commentators.

Evolutionary psychology. Controversies, questions, prospects, and limitations.

Evolutionary psychology has emerged over the past 15 years as a major theoretical perspective, generating an increasing volume of empirical studies and assuming a larger presence within psychological science. At the same time, it has generated critiques and remains controversial among some psychologists. Some of the controversy stems from hypotheses that go against traditional psychological theories; some from empirical findings that may have disturbing implications; some from misunderstandings about the logic of evolutionary psychology; and some from reasonable scientific concerns about its underlying framework. This article identifies some of the most common concerns and attempts to elucidate evolutionary psychology's stance pertaining to them. These include issues of testability and falsifiability; the domain specificity versus domain generality of psychological mechanisms; the role of novel environments as they interact with evolved psychological circuits; the role of genes in the conceptual structure of evolutionary psychology; the roles of learning, socialization, and culture in evolutionary psychology; and the practical value of applied evolutionary psychology. The article concludes with a discussion of the limitations of current evolutionary psychology.