Madison Clarke, Tyler Bonnell, Rosemary Blersch, Christina Nord, Chloé Vilette, Christopher Young, Peter Henzi, Louise Barrett
{"title":"Social induction and the developmental trajectory of participation in intergroup conflict by vervet monkeys.","authors":"Madison Clarke, Tyler Bonnell, Rosemary Blersch, Christina Nord, Chloé Vilette, Christopher Young, Peter Henzi, Louise Barrett","doi":"10.1017/ehs.2025.7","DOIUrl":"10.1017/ehs.2025.7","url":null,"abstract":"<p><p>We assess the proposition that intergroup conflict (IGC) in non-human primates offers a useful comparison for studies of human IGC and its links to parochial altruism and prosociality. That is, for non-linguistic animals, social network integration and maternal influence promote juvenile engagement in IGC and can serve as the initial grounding for sociocultural processes that drive human cooperation. Using longitudinal data from three cohorts of non-adult vervet monkeys (<i>Chlorocebus pygerythrus</i>), we show that non-adults are sensitive to personal (age) and situational risk (participant numbers). The frequency and intensity of participation, although modulated by rank and temperament, both mirrors maternal participation and reflects non-adult centrality in the grooming network. The possibility of social induction is corroborated by the distribution of grooming during IGC, with non-adults being more likely to be groomed if they were female, higher-ranking and participants themselves. Mothers were more likely to groom younger offspring participants of either sex, whereas other adults targeted higher-ranking female participants. Although we caution against a facile alignment of these outcomes to human culturally mediated induction, there is merit in considering how the embodied act of participation and the resultant social give-and-take might serve as the basis for a unified comparative investigation of prosociality.</p>","PeriodicalId":36414,"journal":{"name":"Evolutionary Human Sciences","volume":"7 ","pages":"e9"},"PeriodicalIF":2.2,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11949634/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143755033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Liqiong Zhou, Yuan Chen, Erhao Ge, Aijie Zhang, Yasi Zhang, Juan Du, Ruth Mace, Yiqiang Zhan
{"title":"Having a monk in the family and all-cause mortality: a seven-year prospective cohort study.","authors":"Liqiong Zhou, Yuan Chen, Erhao Ge, Aijie Zhang, Yasi Zhang, Juan Du, Ruth Mace, Yiqiang Zhan","doi":"10.1017/ehs.2025.1","DOIUrl":"10.1017/ehs.2025.1","url":null,"abstract":"<p><p>Religious celibate monks at the household level possibly reduce all-cause mortality risk among non-monk older Tibetans. This study aims to investigate the association between having a celibate monk in a family and the all-cause mortality of non-monk household members in a Tibetan population. Baseline interviews were conducted for 713 agropastoral Amdo Tibetans aged ≥50 years residing in the eastern Tibetan Plateau from 2016 to 2017. The Cox mixed-effects regression model was used to estimate the association between having a celibate monk in a household and the mortality risk of other non-monk household members. Potential confounders included age, sex, household size, educational attainment, household wealth (measured as the number of yaks), marital status, and annual expenditure. During a median follow-up of 7 years, 54 deaths were identified. The results showed that people living in households with celibate monks had a lower risk of all-cause mortality (hazard ratio: 0.31, 95% confidence interval: 0.14, 0.67) as compared with those living in households without celibate monks. The results remained robust after controlling for confounders, suggesting that religious celibate monks at the household level were associated with lower all-cause mortality among non-monk older household members.</p>","PeriodicalId":36414,"journal":{"name":"Evolutionary Human Sciences","volume":"7 ","pages":"e8"},"PeriodicalIF":2.2,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11884931/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143574128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Social comfort and attractiveness perception: impact of prosthetics, physical disability and comfort distance on interpersonal interactions.","authors":"Farid Pazhoohi, Samantha Wing, Alan Kingstone","doi":"10.1017/ehs.2025.5","DOIUrl":"10.1017/ehs.2025.5","url":null,"abstract":"<p><p>Derived from the disease-avoidance model is the hypothesis that people may direct negative cognitive and behavioural responses towards individuals with physical disfiguring conditions, including physical disabilities. According to the behavioral immune system, physical disability-a non-contagious physical disfigurement-may falsely activate cognitive disease-avoidance processes, resulting in prejudicial or negative responses toward individuals with physical disabilities. For the first time this hypothesis is put to the test by investigating whether ratings of attractiveness and comfort for a social interaction vary systematically with physical disability (Studies 1 and 2). In addition, we tested whether these ratings were associated with individual differences in pathogen disgust and perceived vulnerability to disease. In Study 3 we overcame possible methodological limitations by employing a virtual reality (VR) environment. A fourth study was conducted to extend the first two studies by using a more diverse set of avatars. Results from Studies 1 and 2 indicated that disability did not significantly impact comfort ratings for social interactions, although non-disabled stimuli were rated as more attractive. However, Study 3 showed that in a VR environment, participants preferred closer proximity to non-disabled avatars over disabled ones, a preference not mitigated by the presence of prosthetics. Study 4 replicated these findings with varied 2D avatars, showing that disability significantly affected both comfort and attractiveness ratings, with non-disabled avatars rated highest, followed by those with prosthetics, and finally disabled avatars. Despite these findings, the expected relationship between comfort ratings and individual differences in pathogen disgust or perceived infectability did not emerge, challenging the behavioural immune system proposal. The discomfort associated with physical disability may be more related to social stigma or preconceived notions than to an innate disease-avoidance response.</p>","PeriodicalId":36414,"journal":{"name":"Evolutionary Human Sciences","volume":"7 ","pages":"e7"},"PeriodicalIF":2.2,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11949636/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143755029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexander M Ishungisa, Joseph A Kilgallen, Elisha Mabula, Charlotte O Brand, Mark Urassa, David W Lawson
{"title":"Prestige and gender role ideology: a study of young Tanzanian men.","authors":"Alexander M Ishungisa, Joseph A Kilgallen, Elisha Mabula, Charlotte O Brand, Mark Urassa, David W Lawson","doi":"10.1017/ehs.2025.4","DOIUrl":"10.1017/ehs.2025.4","url":null,"abstract":"<p><p>With the objective of informing theoretical accounts of social learning and gendered conflict, we explore the role of prestige in the formation of men's beliefs about gender in a semi-rural but fast urbanizing community in north-western Tanzania. Using focus groups and participant observation, we contrast the extent to which young men view elders and men from the neighbouring city as prestigious, and the beliefs they ascribe to each category. Elders were viewed as prestigious because of their age and position as preservers and teachers of societal norms. Their prestige was culturally mandated, as evidenced by customs bestowing respect. In contrast, only subcategories of city men were deemed prestigious dependent on individual achievement. Prestige was difficult to distinguish from dominance, as both elders and city men can exert penalties on those with differing views. Elders were viewed as mostly, but not always, unsupportive of women's empowerment, whereas city men were viewed as mostly, but not always, supportive of women's empowerment. We conclude that urbanization shifts the distribution of prestige, exposing individuals to novel sources of social influence. However, future studies should be wary not to oversimplify elders as upholders of patriarchal beliefs and city men as universally supportive of women's empowerment.</p>","PeriodicalId":36414,"journal":{"name":"Evolutionary Human Sciences","volume":"7 ","pages":"e10"},"PeriodicalIF":2.2,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11949630/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143754991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Affixation patterns in native language and sequence processing by statistical learning mechanisms.","authors":"Mikhail Ordin","doi":"10.1017/ehs.2025.6","DOIUrl":"10.1017/ehs.2025.6","url":null,"abstract":"<p><p>The suffixing bias (the tendency to exploit suffixes more often than prefixes to express grammatical meanings) in world's languages was identified a century ago, yet we still lack a clear account for why it emerged, namely, whether the bias emerged because general cognitive mechanisms shape languages to be more easily processed by available cognitive machinery, or the bias is speech-specific and is determined by domain-specific mechanisms. We used statistical learning (SL) experiments to compare processing of suffixed and prefixed sequences on linguistic and non-linguistic material. SL is not speech-specific, and we observed the suffixing preference only on linguistic material, suggesting its language-specific origin. Moreover, morphological properties of native languages (existence of grammatical prefixes) modulate suffixing preferences in SL experiments only on linguistic material, suggesting limited cross-domain transfer.</p>","PeriodicalId":36414,"journal":{"name":"Evolutionary Human Sciences","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7617444/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143543786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The cover of randomness: validating implicit methods for the study of sensitive topics.","authors":"Charles Efferson, Sonja Vogt","doi":"10.1017/ehs.2024.48","DOIUrl":"10.1017/ehs.2024.48","url":null,"abstract":"<p><p>We review the methods we developed to study female genital cutting in Sudan and sex-selective abortion in Armenia. These methods were untested at the time of our original research, and here we compare the distinct but overlapping approaches we used to validate our methods for each of the two countries. Additionally, we repeat a number of analyses, including those related to validation, with previously unpublished data from Sudan. All results replicate previous findings. Replicating previous results is encouraging, but we nonetheless argue that validation for Armenia is more convincing than for Sudan. Specifically, even if female genital cutting and the preferential abortion of females are equally sensitive as research topics, son bias is inherently easier to study than cutting because biological sex determination is a random process with no natural analogue in the case of cutting. This randomness provides a kind of cover for research participants who are son-biased but want to create the impression that they are not. This cover, in turn, allows the researcher to resolve any trade-off between methods that produce explicit granular data and methods that produce untraceable, highly aggregated data in favour of methods producing the explicit and granular.</p>","PeriodicalId":36414,"journal":{"name":"Evolutionary Human Sciences","volume":"7 ","pages":"e6"},"PeriodicalIF":2.2,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11896713/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143617471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"When to stop social learning from a predecessor in an information-foraging task.","authors":"Hidezo Suganuma, Aoi Naito, Kentaro Katahira, Tatsuya Kameda","doi":"10.1017/ehs.2024.29","DOIUrl":"10.1017/ehs.2024.29","url":null,"abstract":"<p><p>Striking a balance between individual and social learning is one of the key capabilities that support adaptation under uncertainty. Although intergenerational transmission of information is ubiquitous, little is known about when and how newcomers switch from learning loyally from preceding models to exploring independently. Using a behavioural experiment, we investigated how social information available from a preceding demonstrator affects the timing of becoming independent and individual performance thereafter. Participants worked on a 30-armed bandit task for 100 trials. For the first 15 trials, participants simply observed the choices of a demonstrator who had accumulated more knowledge about the environment and passively received rewards from the demonstrator's choices. Thereafter, participants could switch to making independent choices at any time. We had three conditions differing in the social information available from the demonstrator: choice only, reward only or both. Results showed that both participants' strategies about when to stop observational learning and their behavioural patterns after independence depended on the available social information. Participants generally failed to make the best use of previously observed social information in their subsequent independent choices, suggesting the importance of direct communication beyond passive observation for better intergenerational transmission under uncertainty. Implications for cultural evolution are discussed.</p>","PeriodicalId":36414,"journal":{"name":"Evolutionary Human Sciences","volume":"7 ","pages":"e2"},"PeriodicalIF":2.2,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11810515/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143400233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A season for indulgence.","authors":"Ruth Mace","doi":"10.1017/ehs.2024.49","DOIUrl":"https://doi.org/10.1017/ehs.2024.49","url":null,"abstract":"","PeriodicalId":36414,"journal":{"name":"Evolutionary Human Sciences","volume":"7 ","pages":"e1"},"PeriodicalIF":2.2,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11810506/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143400202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Perceived inequality and variability in the expression of parochial altruism.","authors":"Cody T Ross, Anne C Pisor","doi":"10.1017/ehs.2024.43","DOIUrl":"10.1017/ehs.2024.43","url":null,"abstract":"<p><p>It is commonly argued that humans have generalised predispositions for within-group favouritism and between-group animus (i.e. that humans are <i>parochially altruistic</i>), leading to higher levels of internal conflict in societies with greater diversity. Other research, however, has questioned both the ubiquity of parochial altruism and the role of diversity <i>per se</i> in causing social discord. Here, we use ethnographic, social network and experimental economic game data to explore this topic in two multi-ethnic Colombian communities. We examine the extent to which Afrocolombian and Emberá residents express parochial altruism, finding appreciable variability between communities, and across individuals within communities. When present, parochial altruism appears to be driven by divergent perceptions of group-based economic need, not group identity <i>per se</i>. Our results suggest that diversity may be less likely to cause social discord than past work has suggested, as long as group-based inequalities in wealth, well-being and representation - that can destabilise positive inter-group relationships - are minimised.</p>","PeriodicalId":36414,"journal":{"name":"Evolutionary Human Sciences","volume":"7 ","pages":"e3"},"PeriodicalIF":2.2,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11810521/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143400219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The evolution of similarity-biased social learning.","authors":"Paul E Smaldino, Alejandro Pérez Velilla","doi":"10.1017/ehs.2024.46","DOIUrl":"10.1017/ehs.2024.46","url":null,"abstract":"<p><p>Humans often learn preferentially from ingroup members who share a social identity affiliation, while ignoring or rejecting information when it comes from someone perceived to be from an outgroup. This sort of bias has well-known negative consequences - exacerbating cultural divides, polarization, and conflict - while reducing the information available to learners. Why does it persist? Using evolutionary simulations, we demonstrate that similarity-biased social learning (also called parochial social learning) is adaptive when (1) individual learning is error-prone and (2) sufficient diversity inhibits the efficacy of social learning that ignores identity signals, as long as (3) those signals are sufficiently reliable indicators of adaptive behaviour. We further show that our results are robust to considerations of other social learning strategies, focusing on conformist and pay-off-biased transmission. We conclude by discussing the consequences of our analyses for understanding diversity in the modern world.</p>","PeriodicalId":36414,"journal":{"name":"Evolutionary Human Sciences","volume":"7 ","pages":"e4"},"PeriodicalIF":2.2,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11859121/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143504505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}