Adaptive Human Behavior and Physiology最新文献

Health perceptions are thought to play an important role in human mate preferences. Although many studies have investigated potential relationships between health ratings of faces and facial symmetry, prototypicality, and sexual dimorphism, findings have been mixed across studies. Consequently, we tested for potential relationships between health ratings of faces and the symmetry, prototypicality, and sexual dimorphism of those faces’ shapes. When these three shape characteristics were considered in separate regression models, we observed significant positive relationships between health ratings and both shape symmetry and prototypicality. By contrast, health ratings and sexual dimorphism were not significantly correlated in these analyses. However, in analyses in which symmetry, prototypicality, and sexual dimorphism were entered simultaneously as predictors in a single model, prototypicality, but not symmetry, was significantly correlated with health ratings. Moreover, sexual dimorphism predicted health ratings of female, but not male, faces in these analyses. Collectively, these results suggest that the relationship between symmetry and health ratings is, at least partly, driven by the effect of prototypicality on health perceptions and highlight the importance of considering multiple aspects of face shape when investigating factors that predict perceived health.

Objectives

Body size and shape are sexually dimorphic in humans, with men being characterized with larger upper bodies, while women typically having broader pelvises. Such sexually dimorphic traits, quantified as shoulder to hip ratio (SHR) in men and waist to hip ratio (WHR) in women, serve as cues of an individual’s genetic fitness, reproductive potential, health, and resource holding power, and, thereby, functioning as attractiveness cues to the opposite sex.

Methods

In the current study, we investigated men’s and women’s preference for the opposite sex body shape (WHR in women and SHR in men) in samples from Iran, Norway, Poland, and Russia. Women rated their preference for men’s SHR (1.20 to 1.50) and men rated their preference for women’s WHR (0.55 − 0.85).

Results and Conclusion

Our results showed that Iranian and Norwegian men preferred less feminine WHRs in women compared to Polish and Russian men. Moreover, Iranian women preferred less masculine SHRs in men than women from other countries. Altogether, the current research showed that there are variations in men’s preferences for women’s WHR and women’s preferences for men’s SHR among these countries.

Objectives

Decision-making is often driven and guided by the evaluation of action effects and external cues on action outcomes, which are essential to optimize behavior in an adaptive manner. This work aimed at investigating decision-makers’ sensitivity to external cues (including positive and negative reinforcement) and their flexibility in using feedback to decide whether to stay or change the course of their choices. We also explored the neurofunctional correlates of individuals’ ability to re-assess their decisions in response to feedback, and its possible association with general decision-making styles.

Methods

A realistic decision-making task set in a professional context was devised and administered in addition to the General Decision Making Style (GDMS) inventory. During the task, neurofunctional correlates of affective regulation, cognitive engagement, and information-processing load were non-invasively measured via wearable EEG.

Results

Participants showed a tendency to maintain their decisions following positive reinforcement, or when no explicit feedback was provided. Surprisingly, some of them tended to stay with their decisions also following negative feedback. We observed lower cognitive effort, as marked by lower prefrontal beta power, following positive feedback. Finally, we reported negative correlations between GDMS Dependent style scores and task scores in the positive feedback and no-feedback conditions, along with a positive correlation between GDMS Spontaneous style scores and task scores in the no-feedback condition.

Conclusions

Our findings have implications for understanding adaptive and maladaptive decision-making in contexts in which feedback serves as a compass to orient one’s own performance and prevent the so-called cognitive inertia.

Objective

Decades of research suggest a small, but significant positive association between testosterone (T) and measures of aggression and mating psychology/behavior. More recently, researchers have developed single-dose pharmacological challenge paradigms to test the causal role of T in modulating such processes.

Methods

We summarize and synthesize research from single-dose T administration studies. We first summarize the literature showing effects of T on neural and physiological functioning. Next, we investigate T’s effects on aggressive behavior and mating psychology in humans.

Results

Evidence indicates that a single dose of T can have relatively rapid effects on aggression and mating psychology/behavior. However, such effects are often complex and moderated by personality, genetics, and social-contextual factors.

Conclusion

Popular media discourse suggests that T is straightforwardly intertwined with aggression and sexual behavior. Our review indicates that there is a kernel of truth to T’s links to these complex phenotypic outcomes. However, more work will be necessary to establish the role that psychological, genetic, and social-contextual factors play in moderating associations of T with aggression and sexual behavior.

Objectives

We argue that research in the psychological sciences testing evolutionarily informed questions could benefit considerably from more frequent use of techniques common in behavior genetics.

Methods

We review some of the reasons why data and analytical strategies in behavior genetics confer certain advantages over more traditional forms of data analysis. In particular, we focus on the wide availability of secondary data, the generalizability of data, the capacity of certain designs to bolster causal inference capabilities, and the overall adaptability of the research designs to a wide array of empirical questions.

Results

Not only do we show how the use of sibling designs can be of methodological assistance, but we also demonstrate how they can play a role in refining theories informed by evolution. In order to give a more concrete vision of what this can look like, we offer a type of case study using prior work which has already taken advantage of behavior genetic tools.

Conclusions

Because of the efforts to situate psychological science in the context of evolutionary biology, the field has undergone considerable intellectual growth. We suggest that by simply making more frequent use of tools in behavior genetics, the fields of psychology might further accelerate the progress that is already well underway.

Purpose

Adrenal androgens like dehydroepiandrosterone (DHEA) are important to numerous aspects of health and psychosocial stress physiology. DHEA is responsive to stress, and previous studies have shown chronic stress can be associated with a reduction in DHEA. However, the large majority of this work has been conducted in resource-rich, industrialized societies, with few studies examining how adrenal androgens respond to stressors in environments with persistent resource related concerns. Here we examine the relationships between androgens and chronic psychosocial stress in a sample of Himba pastoralists, in order to determine the relationship between DHEA and stress in a resource-limited environment.

Methods

We assayed DHEA and testosterone in 122 afternoon saliva samples from 46 Himba women aged 18–66, median age 30. Women also completed a chronic psychosocial stress survey, which included social, health, and resource related stressors reported over the past thirty days.

Results

DHEA concentrations show a curvilinear relationship with age, peaking in the mid-30s; testosterone was relatively flat across the life course. DHEA, but not testosterone, was negatively associated with chronic stress scores. In a comparison of question types, resource-related stressors showed the strongest relationship with DHEA.

Conclusion

Our results support findings from previous studies conducted in industrialized societies, showing that chronic stress is associated with a reduction in DHEA concentrations. In contrast, salivary testosterone appears unrelated to chronic stress. Given the associations between DHEA and other aspects of health, better understanding of drivers of DHEA variability can elucidate linkages between stressors and health outcomes.

Purpose

Sexual attraction to males or females is perhaps the largest behavioral sex difference across animal species. Experiments in laboratory mammals show that prenatal androgens mediate this sex difference, but ethical considerations preclude such experimentation in humans. Multiple lines of converging correlational evidence are therefore needed to demonstrate such mediation in humans.

Methods

We review available data linking human sexual orientation to endocrine action, including research on endocrine disorders and biomarkers of early sex hormones. We also perform a meta-analysis across 13 studies comprising 56,804 individuals to investigate a possible link between non-heterosexuality and polycystic ovary syndrome (PCOS), an endocrine condition associated with elevated androgens in females.

Results and conclusions

We find converging evidence that prenatal gonadal hormones influence the development of human sexual orientation and orchestrate its sexual differentiation primarily by regulating patterns of gene expression in the developing brain. Evidence is particularly strong that androgens increase sexual attraction to females. In our meta-analysis, PCOS was more common in non-heterosexual females (r = 0.18, p < 0.001). Some evidence also indicates that estrogens increase sexual attraction to males. We discuss why data may be less clear regarding variation in sexual orientation among males, including the possible existence of subgroups characterized by distinct biological pathways that contribute to same-sex sexual orientation. Moving forward, we propose that multiple measures and/or markers be considered together to better characterize early hormonal action on human sexual orientation.

Men’s beardedness is a sexually dimorphic trait that has played a role in both inter- and intra-sexual selection. It has been suggested that women may prefer bearded men because it may be a cue to men’s underlying physiology and immune function. Beardedness has also been implicated in perceptions of men’s aggressiveness and dominance. In the current research, we explored preferences for men’s beardedness among Iranian and Hispanic women and whether those preferences were moderated by trait pathogen proneness. In Study 1, Hispanic women were recruited and asked to choose the beard profile, from clean-shaven to very long, on a variety of traits (i.e., attractiveness, masculinity, fighting ability, reliable partner, and suitable father). Women more frequently chose light and moderate-length beard types across all outcome measures, and their self-reported levels of disgust was associated with higher preferences for clean-shaven profiles. In Study 2, Hispanic and Iranian women were recruited and asked to rate the beard profiles across the measures. Compared to Iranian women, Hispanic women demonstrated a stronger preference for bearded men. Further, there were cultural differences in self-reported measures of disgust and their preferences for beards in men. The findings from the current study highlight the unique preferences across populations for bearded profiles in men, and they suggest that they may be associated with pathogen trait levels.

Objectives and Method

Anecdotal reports indicate more severe psychological distress following technological catastrophes in comparison to natural disasters. Previous research also suggests a more negative evaluation of the outcomes of disasters if they are manmade. On the other hand, evolutionary neuroscience shows differential neural processing of ancient and modern threats. Building upon this literature, we probed valence and arousal ratings of stimuli depicting natural and technological disasters in several standardized affective stimuli datasets used in neuroscience and psychological research.

Results

Our results show that while technological disasters are rated as slightly less arousing than natural disasters they are rated as significantly more unpleasant.

Conclusion

It seems the evolutionary age of disasters is one of the factors that affect emotional experiences evoked by these threats and can impact our evaluations of catastrophes. We discuss how evolutionary psychology might explain our findings and help us to better understand the biological and learned roots of our biases in risk perception.