Evolutionary Psychology最新文献

We explore the self-reported propensity for virtue signaling of environmentalism and community-minded messages. Evolutionary psychologists have not paid much attention to virtue signaling, although it has implications for social relationships, in-group/out-group dynamics, status, mate choice, and kinship. We tested three hypotheses regarding sex differences in samples (N = 20,423) obtained in 2020 from Canada, Japan, and the USA. First, across all samples, we hypothesized that both sexes use environmentalism and community-mindedness to engage in virtue signaling, which was supported. Second, we hypothesized that conspicuous ethical consumption, as a form of virtue signaling, is performed more by women than by men, which was not supported. Contrary to our prediction, men reported higher engagement in conspicuous ethical consumption, suggesting that status motives may have a strong role in their virtue signaling behaviors. Third, we hypothesized that known sex differences in the Big Five personality traits are linked to virtue signaling. That is, typically, women are reported to score higher than men in neuroticism, extroversion, agreeableness, and conscientiousness, while men score higher on openness than women. Our findings partially support this pattern. Last, we report on intercultural differences. We close with a discussion of the usefulness of studying virtue signaling from an evolutionary perspective.

Across four experiments, participants were asked to process unrelated common nouns after listening to pleasantness processing instructions, survival processing instructions, or story processing instructions. In Experiment 1, participants were provided with a list of words and were asked to list various ways that the words were pleasant or unpleasant, list ways that the words could help them survive in an ancestral grasslands scenario, or use the words in the list to create a short story. In Experiment 2, participants were asked to perform similar tasks, but rather than being provided with a word list at the start of the experiment, words were presented one at a time at a fixed rate. In Experiment 3, participants were asked to rate words as they were presented one at a time regarding their perceived pleasantness, their relevance to an ancestral survival scenario, or the ease with which they could be included in a short story. In Experiment 4, a combined survival-story condition was included along with survival, story, and pleasantness processing instructions to determine whether combining story and survival processing produces an additive effect on recall performance. Across all four experiments, after a brief delay, the story processing condition produced either enhanced or comparable incidental recall performance to the survival processing scenario, and both of those conditions produced enhanced recall performance relative to the pleasantness processing scenario. These results suggest that processing information in the context of a story, like survival processing, may represent one of the best deep processing tasks identified to date.

We tested the adaptive hypothesis of psychopathy in human and computer Prisoner Dilemma (PD) matches. From a cohort of 448 male undergraduates who completed the Levenson Self-Report Psychopathy Scale (LSRP), 31 high psychopathic (PP) and 29 low PP students, sampled from upper and lower quartiles of the cohort, played a 40-round PD match in which real money was at stake. The human matches were of three kinds: Low PP versus Low PP, Low PP versus High PP, and High PP versus High PP. In computer simulations, the empirical defection probabilities from High and Low PP human players were entered in a three-player round-robin match with tit-for-tat (TFT) or a less cooperative variant. The strategies proliferated or dwindled in subsequent generations in proportion to their winnings and the matches continued until two players became extinct. In the human matches, High PP players had higher earnings in matches with Low PP and lower earnings in matches with other High PP players. In the computer matches, TFT drove both Low PP and High PP to extinction. However, High PP drove both Low PP and a less cooperative variant of TFT to extinction. Our experiments showed that PP traits may proliferate in two ways. People with low psychopathy engage in selfish behaviors also and people with high psychopathy are capable of cooperation and deter defection by means of harsh punishment. The broader significance of the in silico experiment is that randomness in social encounters may allow behavioral expressions of psychopathy to thrive over an altruistic and reciprocal strategy such as TFT.

The mnemonic effects of animacy and threat were explored with photographic stimuli. After studying labeled photographs of animate and inanimate items that were either threatening or nonthreatening, participants recalled significantly more animate items than inanimate items and more threatening items than nonthreatening items. However, a recognition test of the photographs showed higher accuracy for inanimate photographs. Eyetracking technology was utilized in the second experiment to determine if participants' eye movements are affected by the animacy or threat status of stimuli and whether the pattern of eye movements were similar to the pattern of memory results. The free recall patterns followed the typical effects of animacy and threat, but a reverse animacy effect was again found in photograph recognition. Further, eyetracking measures revealed patterns similar to those of the free recall data, with more fixations and more time spent viewing animate items and threatening items. The data present a dichotomy between memory for the specific details of the studied stimuli (i.e., the details of the studied photographs) and memory for the more general semantic information of the studied stimuli (i.e., the ability to recall more animate items than inanimate items). The results of the eyetracking show that animate items and threatening items are more likely to capture visual attention of participants when compared to inanimate items and nonthreatening items, which could be at least partly responsible for the increased memory for these item types in recall memory, but not necessarily recognition memory.

The Behavioral Immune System (BIS) drives disgust-based avoidance, but its response to immunological changes during pregnancy is understudied. The Compensatory Prophylaxis Hypothesis (CPH) predicts heightened disease-avoidant social behavior in early pregnancy due to immunosuppression. We examined whether first-trimester women show reduced willingness to engage with outgroup members or individuals displaying infection signs compared to later pregnancy stages and postpartum. We also assessed moderation by perceived vulnerability to disease (PVD) and perceived COVID-19 threat. Data were collected in Poland during the COVID-19 pandemic via online surveys in two studies. In the cross-sectional Study 1 (N = 425, age 18-46, M = 29.64, SD = 5.37), pregnant participants at different stages of pregnancy assessed their willingness to engage in social contact with individuals displaying or not displaying infection cues shown in photographs, and then completed measures of PVD and Perceived Threat of COVID-19. The longitudinal Study 2 (N = 112, age 22-41, M = 30.14, SD = 4.05) employed the same procedure, administered four times-during the first, second, and third trimesters, and postpartum. Findings did not support CPH. Social avoidance was unrelated to the pregnancy stage but significantly associated with PVD and COVID-19 threat. Results underscore the situational and individual flexibility of BIS responses.

Evolutionary theorizing predicts that parenthood is associated with higher hedonic wellbeing (experiencing more positive and fewer negative emotions), higher eudaimonic wellbeing (experiencing greater meaning in life), and greater life satisfaction. To test this hypothesis, we analyzed a dataset comprising 5,556 participants drawn from 10 different nations. We found a small positive effect of parenthood on eudaimonic wellbeing, which was more pronounced for women. Conversely, we found virtually no differences between parents and nonparents across all measured dimensions of hedonic wellbeing and life satisfaction. Furthermore, for most dimensions, we did not detect significant interactions between parenthood status and sex, age, or relationship status. Additionally, participants with children reported lower relationship satisfaction than those without children; however, the observed difference was small. Our results contrast with evolutionary predictions, as well as empirical findings showing that parents perceive their children as sources of positive emotions and life purpose, creating a paradox for which we offer a possible resolution.

Ornamentation is a widespread feature of human material culture, yet its preference varies across societies. We tested the hypothesis that variation in ornamentation preference correlates with socioecological factors, comparing 215 parent-child dyads from three societies differing in WEIRD characteristics: Scotland, Pakistan, and Papua New Guinea. We found that less WEIRD societies exhibit stronger preferences for ornamentation, consistent with adaptive socioecological influences on aesthetic valuation. Moreover, a decline in ornamentation preference with age was observed only in the Western sample, suggesting cultural suppression of ornamentation across development. These findings support the view that children's aesthetic preferences may more closely reflect evolved, foundational biases toward ornamentation, which are subsequently modulated by cultural context. Investigating such developmental trajectories is crucial to understanding the biological basis and evolutionary origins of human aesthetic preferences.

Lanthanides have emerged as important metal cofactors for biological processes. Lanthanide-associated metabolisms are well-studied in leaf symbiont methylotrophic bacteria, which utilize reduced one-carbon compounds such as methanol for growth. Yet, the importance of lanthanides in plant-microbe interactions and on microbial physiology and colonization in plants remains poorly understood. To investigate this, 344 pink-pigmented facultative methylotrophs were isolated from soybean leaves by selecting for bacteria capable of methanol oxidation with lanthanide cofactors, but none were obligately lanthanide-dependent. Phylogenetic analyses revealed that all strains were nearly identical to each other and are part of the extorquens clade of Methylobacterium, despite variability in genome and plasmid sizes. Strain-specific identification was enabled by the higher resolution provided with rpoB compared to 16S rRNA as marker genes. Despite the low strain-level diversity, the metabolic capabilities of the collection diverged greatly. Strains encoding identical lanthanide-dependent alcohol dehydrogenases displayed significantly different growth rates and/or final ODs from each other on alcohols in the presence and absence of lanthanides. Several strains also lacked well-characterized lanthanide-associated genes thought to be important for phyllosphere colonization. Additionally, 3% of our isolates were capable of growth on sugars and 23% were capable of growth on aromatic acids, substantially expanding the range of substrates utilized by Methylobacterium extorquens in the phyllosphere. Our findings suggest that the expansion of metabolic capabilities, as well as differential usage of lanthanides and their influence on metabolism, among closely related strains point to evolution of niche partitioning strategies to promote colonization of the phyllosphere.

Human life history (LH) variation stems from developmental phenotypic responses to childhood environments. As with other psychological constructs, LH variation can be assessed by asking questions that are statistically linked to the underlying LH traits. This study introduces the fast-slow scale (FSS), a 35-item questionnaire designed to measure fast-slow LH strategies in adults. The FSS asks questions about trade-offs involving energy, resources, and time, as well as trade-off questions concerning the life domains of sexuality, sociality, and cognitive style. Two validation studies based on community samples totaling 1,491 participants support the internal structural and the external nomological validity of the FSS.

Researchers have suggested that men with more masculine facial characteristics have stronger immune systems but are perceived to be less likely to invest resources in partners and offspring. How women resolve this putative trade-off between the costs and benefits of choosing a masculine mate have previously been reported to be associated with women's openness to uncommitted relationships (i.e., their sociosexuality) and self-perceived mate value. However, not all studies have reported these links and the methods used to assess masculinity preferences in studies reporting these patterns of results (forced-choice tests using stimuli in which masculinity was experimentally manipulated) have recently been criticized for having low ecological validity. Consequently, we tested whether sociosexuality or self-perceived mate value predicted women's masculinity preferences when masculinity preferences were assessed using ratings of individual natural (i.e., unmanipulated) male faces. Our analyses show no evidence that individual differences in women's sociosexuality or self-perceived mate value significantly predicted masculinity preferences. Thus, our results do not support the proposal that sociosexuality and/or self-perceived mate value are important sources of individual differences in women's preferences for male facial masculinity.