Evolutionary Psychology最新文献

In this article, we examine the relations between extreme environmental harshness during childhood and personal fertility ideals in African students. The study is informed by biological models of predictive adaptive responses (PAR) for individual reproductive schedules in the context of life history theory (LHT). Following theoretical models of external and internal environmental cues, we tested whether war and starvation during childhood differentially predict African students' personal fertility ideals in terms of their desired number of children and their desired age of first parenthood. The data were collected in eight different countries from sub-Saharan Africa with an overall sample size of N = 392. Standardized effect estimates were obtained using a Bayesian approach. The results suggest that war and starvation are predictive of the desired number of children, but not of the desired age of first parenthood. Moreover, the effect estimates varied considerably between females and males, indicating possible interactions between the two independent variables depending on the students' sex. Furthermore, we found a small negative correlation between the desired number of children and the desired age of first parenthood, providing only weak support for a clustering of the two variables on a slow-fast continuum. The results are discussed in light of current models of individual life histories in humans.

Evidence is abundant that evolution by selection has produced sex differences in the design of adaptations to solve the problems surrounding reproduction. A prime example is the design of human jealousy, which research suggests is triggered by distinct evoking acts that are specific challenges for women and men in their exclusive reproductive bond. It follows that jealousy would be directed toward driving away interlopers who could potentially threaten the bond with the romantic partner or increase mate retention efforts in response to sex-specific threats. To explore this possibility, we use as a methodological innovation an economic game for the evocation of jealousy. With a modified dictator game, we showed men and women in a committed relationship, conditions in which the partner or an intrasexual rival allocates money to (investing condition), or obtains money from (receiving condition), the partner or an opposite sex third party that they recently met. A sample of 56 heterosexual couples (n = 112) participated in a laboratory setting. Our results show the different scenarios of this dictator game exerted the expected evocation of jealousy (controlling individual differences), with women being more jealous by the partner's allocation of resources to a rival, and men reporting slightly more jealousy by their partner receiving money from a rival. We discuss the implications of this method to advance the comprehension of the adaptive function of sex differences in jealousy, the use of economic games, and possible modifications to improve the similarity of the game to a real assessment of actual male jealousy.

Recent research has examined digital dating abuse through an evolutionary lens, finding people who report intrasexual competitiveness engage in digital dating abuse. Here, we replicated this finding and extended the literature by examining the role of the Big Five personality traits in the perpetration of digital dating abuse, which, to our knowledge, has not been examined in relation to digital dating abuse (n=280). This paper reports findings showing intrasexual competitiveness positively predicts the perpetration of digitaldating abuse; whereby high intrasexual competition is related to high levels of digital dating abuse. Agreeableness was a negative predictor of digital dating abuse; whereby high agreeableness was related to low perpetration of digital dating abuse. Our findings extend the literature exploring digital dating abuse through an evolutionary lens.

We were interested in how people in a romantic relationship would perceive the intelligence of their partners who have high or low trait anger. Specifically, we referred to the tension between compassion (low anger) and competence (high intelligence) in mate choice. Some evolutionary theories suggest that mating might be considered a bargaining process between these two higher-order attributes. Our study involved 148 heterosexual couples in romantic relationships. We measured the relationship between relationship satisfaction, trait anger, objective intelligence, self-assessed intelligence, and subjectively assessed partners' intelligence. We found that angrier men were less satisfied in their romantic relationship than those men who were less angry, and their partners were also less satisfied in the relationship. Additionally, women perceived angrier men as less intelligent, an effect that remained after controlling for men's objective intelligence. Lastly, we found that women's perception of their partner's intelligence mediated the link between men's anger and relationship satisfaction for both sexes. Our findings suggest that both anger and intelligence play important roles in romantic relationship functioning, consistent with evolutionary theories that emphasize the value of competence (i.e., intelligence) and compassion (i.e., low anger) in romantic partners. Furthermore, our study highlights the importance of women's perception of their partner's intelligence in determining the quality of the relationship.

Jealousy may have evolved to motivate adaptive compensatory behavior in response to threats to a valued relationship. This suggests that jealousy follows a temporal sequence: A perceived relational threat induces state feelings of jealousy which in turn motivates compensatory behavior, such as mate retention effort. Yet to date, tests of this mediation model have been limited to cross-sectional data. This study is the first to experimentally test this theoretical model. Men and women (N = 222) who were currently in committed romantic relationships were primed with an imagined partner infidelity (versus control) scenario. Participants then completed measures of state jealousy and intended mate retention behavior. Results found that those primed with the infidelity threat scenario experienced an increase in state jealousy, which in turn predicted more intended benefit-provisioning and cost-inflicting mate retention. Findings suggest that jealousy mediated the relationship between infidelity threat and intended mate retention behavior, supporting the evolutionary account of state jealousy.

Red color signals dominance in both animals and humans. This study investigated whether a red background color influences the perception of dominance in human faces and geometric shapes. The facial stimuli consisted of computer-generated faces, quantitatively morphed into nine levels of dominance, ranging from less dominant to more dominant. This included East-Asian female faces in Experiment 1 and male faces in Experiment 2. The face stimuli were presented against three background colors: red, green, and gray. Participants were instructed to categorize the faces as either obedient or dominant by pressing the corresponding labeled keys. The results showed that faces were more likely to be perceived as dominant when presented against a red background than against green or gray backgrounds, for both female and male faces. Additionally, two questionnaire surveys showed that the perception of dominance also increased for shapes presented against a red background. However the effect of red diminished in the absence of the actual perception of the color red. These results suggest that the perception of dominance in both human faces and objects is enhanced by the presence of red, possibly due to evolutionary factors related to the perception of red.

Until relatively recently, the study of victimization has been largely outside the purview of behavioral geneticists and evolutionary psychologists. Recent victimology research, however, has shown that genetic and evolutionary forces are connected to the risk of victimization. The current study expands on these findings by examining whether genetic influences differentially explain victimization in males and females. To do so, we use a sample of sibling pairs drawn from the National Longitudinal Study of Adolescent to Adult Health (Add Health; N = 4,244). The analyses revealed no significant quantitative sex differences in the etiology of adult victimization. However, the results of this study do highlight the importance of accounting for genetic factors when studying the etiology of specific types of adult victimization. We conclude by discussing the implications of the current study for future research.

Morphological femininity depends mainly on estrogen levels at puberty and is perceived as a cue of a woman's biological condition. Due to the immunostimulant properties of estradiol, estradiol-dependent feminine traits are expected to be positively related to immunity. However, heightened immunity in women may increase the risk of autoimmune disease, thus the relationship between femininity and immune quality may be complex. This study aimed to assess the relationship between morphological femininity and both the occurrence and severity of Hashimoto thyroiditis (HT) in women of reproductive age. Moreover, 95 women with HT and 84 without HT (all between 20 and 37 years) participated in the study. Morphological femininity was assessed based on somatic measurements of sexually dimorphic traits (2D:4D ratio, WHR, breast size, facial sexual dimorphism). The occurrence and severity of HT were assessed by serum TPOAb levels. The results showed that only the 2D:4D ratio of the right hand was higher in the HT group, indicating higher femininity in these women. However, there was also a positive relationship between facial femininity and TPOAb level in women with HT, indicating a higher severity of the disease. The results suggest that prenatal and pubertal exposure to estrogens may increase the probability or severity of autoimmune diseases in adulthood, but the relationship is tentative.

An overrepresentation of stepchildren as victims of filicide has been explained as a consequence of 'discriminative parental solicitude'. The idea being that Darwinian selection has favoured parental love and concern only for biological children, and when such parental feelings are absent, as in stepparents, conflicts with a child could easier escalate to lethal violence. An alternative explanation for this overrepresentation of stepchildren is that risk factors for filicide, such as criminal behaviour and mental health problems, are more prevalent in stepparents. This study focused on paternal filicide in Sweden and investigated (i) if stepchildren are overrepresented as victims of filicide compared with biological children, (ii) if filicides are committed in a context that implies a 'conflict with the child victim' and (iii) if stepfathers and biological fathers differ in characteristics associated with filicide risk. The analyses showed that stepchildren were overrepresented as victims compared with children of fathers in families with two biological parents and this overrepresentation was even higher in young children. Children of single biological fathers and children of non-residential biological fathers were also overrepresented as victims of filicide. Less than 20 percent of the filicides were committed in the context of a 'conflict with the child' and in these cases only stepchildren were overrepresented as victims. In the population at large, both stepfathers and single biological fathers had higher rates of mental health problems, violent criminality and illegal possession of drugs compared with fathers in families with two biological parents.

Previous studies have found a high degree of assortative mating for educational attainment (r = .56). However, this can be confounded by cohort effects or country effects, where certain nations may have more pronounced assortative mating than others. In addition, method variance regarding how educational attainment is measured may also result in heterogeneity of effect sizes. Effect sizes were gathered from various datasets and from academic literature, resulting in a large collection of effect sizes (k = 1498, n = 9,159,098), spanning 84 different countries. Assortative mating for educational attainment was stronger than what previous literature suggested (r = .66, [.64, .68]), largely due to the fact that assortative mating for educational attainment is stronger when latent methods are used. The strongest predictors of assortative mating for education between countries were individualism (r = -.61, p < .001) and HDI (r = -.56, p < .001). Assortative mating over time was found to vary by region. Capitalist Europe experienced an increase in assortative mating for education, while Communist Europe experienced a decrease. The United States had a non-linear trend in assortative mating for educational attainment, as it decreased from 1875 to 1926, increased from 1926 to 1945, decreased from 1945 to 1958, increased from 1958 to 1977, and decreased from 1977 onwards.