Adaptive Human Behavior and Physiology最新文献

A key theoretical component of the behavioral immune system is its functional flexibility, where an individual’s reaction to pathogenic stimuli is designed to fluctuate based on individual costs and benefits. For example, those who perceive themselves to be more vulnerable to disease or are in poorer health should react more aversely to possible pathogenic agents because of the higher costs of infection. To test this hypothesis, we collected measures of current individual health (i.e., self-reported general health and self-perceived infectibility) and three domains of disgust in two studies: an in-person sample of United States university students and a global online sample of diverse ages. We also collected and assayed saliva samples for secretory immunoglobulin A (sIgA), provided by the university students. Results showed that lower sIgA and higher perceived infectibility independently predicted higher pathogen disgust. Poor self-reported general health was associated with higher pathogen disgust in the university sample, but not in the online sample. Finally, pathogen disgust mediated the effect of perceived infectibility on behavioral avoidance motivation. Overall, our findings support the functional flexibility of the behavioral immune system, such that those who are more vulnerable to disease are more likely to respond aversely to situations with high pathogen load; however, future research should consider other contextual factors which affect the strength of this relationship between individuals and populations.

Introduction

The cooperative breeding framework suggests that help from extended family members with childrearing is important adaptation for our species survival, and it is universal. However, the degree of alloparental help may vary between societies, families, and over time. We hypothesized that maternal and paternal effort, as well as alloparental care, would depend both upon resource availability (SES) and different mating opportunities for males and females in three countries: Brazil, Russia, and the USA.

Methods

We analyzed the intergenerational interactions between family members during childcare via Structural Equation Modeling (SEM) in R-software. Online samples were collected from Brazil (N = 538), Russia (N = 502), and the USA (N = 308).

Results and Discussion

The results of our study are consistent with previous research on life history (LHT) plasticity, which has shown a negative correlation between the perceived childhood SES and perceived parental effort. However, our models indicated a possible cultural difference in the estimates of poverty paths: in Brazilian and American samples, SES had a greater impact on paternal care than on maternal, while in Russia, poverty had a greater effect on mothers’ effort. This reversed effect size on maternal versus paternal effort in Russia may suggest that Russian mothers experience a trade-off between working outside the home and direct childcare, while Russian fathers may adopt a “faster” LHT strategy as they are the limited sex in the mating pool.

Our findings also demonstrate that the parental effort of both parents was positively associated, indicating their mutualistic relationship. We also found that according to the recollections of respondents’ maternal grandparents usually compensate the lack of paternal effort, but their help, as well as the help of paternal grandparents, was indifferent to the poverty cues.

Purpose

Early-life adversity (ELA) affects health by altering the hypothalamic–pituitary–adrenal (HPA) axis. Most studies show that ELA blunts HPA responsivity while others show the opposite. To explain this inconsistency, researchers investigate factors that alter associations between ELA and HPA responsivity. One factor could be conditions that participants encounter before exposure to stressors. Life-history theory suggests ELA alters HPA function by signalling high mortality. Similarly, death thoughts signal acute mortality. Research suggests that thinking about death induces behaviors typical of ELA subjects. We therefore tested whether death thoughts before acute stress mimics the effects of ELA on HPA responsivity.

Methods

One hundred twenty eight healthy young men were classified as high or low ELA based on retrospective self-report, and then primed with death thoughts (experimental group) or completed neutral questionnaires (control group). They then underwent a psychosocial stress task. Salivary cortisol was sampled repeatedly to assess HPA responsivity to stress.

Results

In the control group, higher ELA correlated with lower cortisol responsivity. In the experimental group, subjects with high ELA did not show altered cortisol responsivity, but low ELA participants displayed significantly blunted responsivity in response to death thoughts. Thus, low ELA participants primed with death thoughts resembled high ELA participants not exposed to death thoughts.

Conclusion

Our findings suggest that subtle death cues present in the testing environment may confound associations between ELA and HPA function and should be controlled for in future studies. We discuss how life-history theory could explain how both long-term (ELA) and acute (mortality salience) experiences alter HPA function.

Objectives: A bibliometric analysis by Zagaria (2024) claimed that research in Evolutionary Psychology (EP) lags behind research grounded in the Standard Social Science Model (SSSM) in prevalence and growth rate, questioning EP’s status as a scientific revolution. This commentary aims to re-evaluate Zagaria’s findings and conclusions. We raise two major concerns about his analysis. First, Zagaria’s EP syntax excluded key EP terms like fitness, psychological adaptation, and parental investment, while the SSSM syntax included homonyms (e.g., culture) not always relevant to SSSM (e.g., tissue culture in medicine). Second, the analysis included non-scientific journals from fields like gender studies, skewing results since EP is not intended to influence non-scientific fields like dance therapy or tourism studies. Focusing on high-impact psychology journals would better reflect EP’s influence. Methods: We revised the SSSM syntax to “cultural” and updated the EP syntax by adding “inclusive fitness,” “parental investment,” and “psychological adaptation.” Our analysis also used year-by-year data and 5- and 10-year rolling averages to assess trends more accurately. Results: Our analysis found that growth in EP and SSSM research is comparable over time, and the ratio of SSSM to EP papers was overstated by at least 23%. Conclusion: We highlight metrics that should be weighted more heavily than publication quantity, such as effect magnitude, universality, and replicability. By these metrics, EP is arguably outperforming the SSSM and embodies elements of the Kuhnian scientific revolution discussed by Zagaria (2024). This commentary offers a more optimistic vision for EP’s current status and future direction.

Purpose

Differences in choices provide a window into the variety of human preferences and behaviors. Most non-trivial decisions recruit multiple regions of the brain with activity that shows substantial variation across individuals and also depends on personality traits and attitudes.

Methods

The present study measured nine physiologic factors and collected 15 types of psychological data while participants made decisions in standard tasks measuring risk aversion, patience, altruism, cooperation, generosity, trust, and trustworthiness. Robust predictors were defined as those that were statistically significant in both forward and backward stepwise regressions using all the collected independent variables.

Results

The analysis showed that multiple measures of physiologic stress decrease cooperative behaviors while testosterone consistently increased antisocial behaviors. In addition, cognitive abilities robustly increased patience but decreased cooperation, while those more satisfied with their lives were more trustworthy. Participants scoring high on the personality trait of imagination were shown to be less altruistic and generous, while neuroticism increased prosociality.

Conclusion

This study identified key drivers of behaviors that should be measured in decision-making experiments in order to capture the multiple factors that affect choices. We conclude with suggestions on how to establish causal relationships between the identified factors and decisions.

Purpose

Attracting and maintaining a romantic partner requires considerable effort. In the current study, we aimed to test the hypothesis that fear of singlehood is a primary factor driving individuals to allocate scarce resources in the mating domain.

Methods

We conducted a close-ended survey with a sample of 990 Greek and Turkish-speaking participants.

Results

We found that that a stronger fear of singlehood was associated with higher mating effort. Moreover, voluntarily single participants experienced lower fear of singlehood compared to other categories of singles and individuals in intimate relationships. Additionally, higher self-esteem was associated with lower fear of singlehood. We also identified a significant indirect effect of relationship status and self-esteem on mating effort through fear of singlehood. Specifically, involuntarily single individuals tended to exert more mating effort due to heightened fear of singlehood compared to those in other relationship status categories. Furthermore, higher self-esteem was associated with reduced mating effort, as it was associated with lower fear of singlehood. These findings held true across both the Greek and Turkish samples.

Conclusion

Relationship status and self-esteem play a role in mating effort through fear of singlehood.

Purpose

This study examines the impact of first-person versus third-person mental visualizations of self on prosocial behavior, building on research that links perspective-taking to differences in moral judgments, agency, and self-awareness. A first-person perspective of self typically enhances feelings of agency, personal responsibility, and empathy, which has been hypothesized to lead to greater helping. However, a third-person perspective of self may heighten self-awareness, potentially leading to a greater focus on reputation management and consequently, helping.

Methods

In two preregistered experiments we test the impact of perspective taking of self on altruistic behavior. Experiment One (n = 599) manipulates generalized perspective taking of self during memory recall and assesses its effect on the amount of time individuals engage in a charitable activity. Experiment Two (n = 271) extends this investigation to explore how targeted perspective taking of self while visualizing a future volunteer activity influences intention to volunteer and actual volunteering.

Results

Across both experiments we found no evidence of an effect of perspective taking on altruistic behavior.

Conclusion

Our results contrast with previous research suggesting that differences in mental visualizations of self influence prosocial behaviors. These findings underscore the complexity of this research area and call for a deeper examination of the theoretical frameworks and methodology used in studies.