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Individual variation and the source-sink group dynamics of extra-group paternity in a social mammal.Behavioral Ecology : Official Journal... 2019Movement of individuals, or their genes, can influence eco-evolutionary processes in structured populations. We have limited understanding of the extent to which spatial...
Movement of individuals, or their genes, can influence eco-evolutionary processes in structured populations. We have limited understanding of the extent to which spatial behavior varies among groups and individuals within populations. Here, we use genetic pedigree reconstruction in a long-term study of European badgers () to characterize the extent of extra-group paternity, occurring as a consequence of breeding excursions, and to test hypothesized drivers of variation at multiple levels. We jointly estimate parentage and paternity distance (PD; distance between a cub's natal and its father's social group), and test whether population density and sex ratio influence mean annual PD. We also model cub-level PD and extra-group paternity (EGP) to test for variation among social groups and parental individuals. Mean PD varied among years but was not explained by population density or sex ratio. However, cub-level analysis shows strong effects of social group, and parental identities, with some parental individuals being consistently more likely to produce cubs with extra-group partners. Group effects were partially explained by local sex ratio. There was also a strong negative correlation between maternal and paternal social group effects on cub paternity distance, indicating source-sink dynamics. Our analyses of paternity distance and EGP indicate variation in extra-group mating at multiple levels-among years, social groups and individuals. The latter in particular is a phenomenon seldom documented and suggests that gene flow among groups may be disproportionately mediated by a nonrandom subset of adults, emphasizing the importance of the individual in driving eco-evolutionary dynamics.
PubMed: 30971858
DOI: 10.1093/beheco/ary164 -
The American Naturalist Feb 2014Conflicts of interest over resources or reproduction among individuals in a social group have long been considered to result in automatic and universal costs to group...
Conflicts of interest over resources or reproduction among individuals in a social group have long been considered to result in automatic and universal costs to group living. However, exploring how social conflict varies with group size has produced mixed empirical results. Here we develop a model that generates alternative predictions for how social conflict should vary with group size depending on the type of benefits gained from being in a social group. We show that a positive relationship between social conflict and group size is favored when groups form primarily for the benefits of sociality but not when groups form mainly for accessing group-defended resources. Thus, increased social conflict in animal societies should not be viewed as an automatic cost of larger social groups. Instead, studying the relationship between social conflict and the types of grouping benefits will be crucial for understanding the evolution of complex societies.
Topics: Animals; Behavior, Animal; Conflict, Psychological; Game Theory; Models, Biological; Population Density; Social Behavior
PubMed: 24464203
DOI: 10.1086/674378 -
Current Biology : CB Mar 2011Discriminating among individuals is a critical social behavior in humans and many other animals and is often required for offspring and mate recognition, territorial or...
Discriminating among individuals is a critical social behavior in humans and many other animals and is often required for offspring and mate recognition, territorial or coalitional behaviors, signaler reliability assessment, and social hierarchies. Being individually discriminated is more difficult in larger groups, and large group size may select for increased individuality-signature information-in social signals, to facilitate discrimination. Small-scale studies suggest that more social species have greater individuality in their social signals, such as contact calls. However, this relationship has not been evaluated in a broader-scale evolutionary context or in social signals other than contact calls. It is not yet known whether social group size may be viewed as a general evolutionary driver of individuality. Here we show a strong positive evolutionary link between social group size in sciurid rodents and individuality in their social alarm calls. Social group size explained over 88% of the variation in vocal individuality in phylogenetic independent contrasts. Species living in larger groups, but not in more complex groups, had more signature information in their calls. Our results suggest that social group size may promote the evolution of individual signatures and that the sociality-individuality relationship may be a general phenomenon in nature.
Topics: Animal Communication; Animals; Biological Evolution; Discrimination, Psychological; Group Structure; Individuality; Phylogeny; Principal Component Analysis; Sciuridae; Sound Spectrography; Species Specificity
PubMed: 21333537
DOI: 10.1016/j.cub.2011.01.051 -
Cognitive Psychology Jun 2018Although it is well known that action observation triggers an imitative response, not much is known about how these responses develop as a function of group size....
Although it is well known that action observation triggers an imitative response, not much is known about how these responses develop as a function of group size. Research on social contagion suggests that imitative tendencies initially increase but then stabilize as groups become larger. However, these findings have mainly been explained in terms of interpretative processes. Across seven experiments (N = 322), the current study investigated the contribution of sensorimotor processes to social group contagion by looking at the relation between group size and automatic imitation in a task that involved minimal interpretation. The results of Experiments 1-2 revealed that automatic imitation increased with group size according to an asymptotic curve on congruent trials but a linear curve on incongruent trials. The results of Experiments 3-7 showed that the asymptote on congruent trials disappeared when no control was needed, namely in the absence of incongruent trials. This suggests that the asymptote in the relation between group size and automatic imitation can be explained in terms of strategic control mechanisms that aim to prevent unintended imitative responses. The findings of the current study are in close correspondence with previous research in the social domain and as such support the hypothesis that sensorimotor processes contribute to the relation between group size and social contagion.
Topics: Adult; Female; Group Processes; Humans; Imitative Behavior; Male; Psychomotor Performance; Social Conformity; Young Adult
PubMed: 29501776
DOI: 10.1016/j.cogpsych.2018.02.001 -
Cognitive Psychology Sep 2021Across three studies (N = 607), we examined people's use of a dichotomizing heuristic-the inference that characteristics belonging to one group do not apply to another...
Across three studies (N = 607), we examined people's use of a dichotomizing heuristic-the inference that characteristics belonging to one group do not apply to another group-when making judgments about novel social groups. Participants learned information about one group (e.g., "Zuttles like apples"), and then made inferences about another group (e.g., "Do Twiggums like apples or hate apples?"). Study 1 acted as a proof of concept: Eight-year-olds and adults (but not 5-year-olds) assumed that the two groups would have opposite characteristics. Learning about the group as a generic whole versus as specific individuals boosted the use of the heuristic. Study 2 and Study 3 (sample sizes, methods, and analyses pre-registered), examined whether the presence or absence of several factors affected the activation and scope of the dichotomizing heuristic in adults. Whereas learning about or treating the groups as separate was necessary for activating dichotomous thinking, intergroup conflict and featuring only two (versus many) groups was not required. Moreover, the heuristic occurred when participants made both binary and scaled decisions. Once triggered, adults applied this cognitive shortcut widely-not only to benign (e.g., liking apples) and novel characteristics (e.g., liking modies), but also to evaluative traits signaling the morals or virtues of a social group (e.g., meanness or intelligence). Adults did not, however, extend the heuristic to the edges of improbability: They failed to dichotomize when doing so would attribute highly unusual preferences (e.g., disliking having fun). Taken together, these studies indicate the presence of a dichotomizing heuristic with broad implications for how people make social group inferences.
Topics: Adult; Child, Preschool; Emotions; Heuristics; Humans; Intelligence; Judgment; Learning
PubMed: 34330016
DOI: 10.1016/j.cogpsych.2021.101408 -
Journal of Personality and Social... Oct 2020Evidence of group bias based on race, ethnicity, nationality, and language emerges early in the life span. Although understanding the initial acquisition of group bias...
Evidence of group bias based on race, ethnicity, nationality, and language emerges early in the life span. Although understanding the initial acquisition of group bias has critical theoretical and practical implications, precisely how group biases are acquired has been understudied. In two preregistered experiments, we tested the hypothesis that generalized social group biases can be acquired through exposure to positive nonverbal signals directed toward a novel adult from one group and more negative nonverbal signals directed toward a novel adult from another group. We sought to determine whether children would acquire global nonverbal signal-consistent social group biases that extended beyond their explicit social preferences, by measuring children's preferences, imitation, and behavioral intentions. Supporting our preregistered hypotheses, preschool-age participants favored small and large groups whose member received positive nonverbal signals, relative to groups whose member received more negative nonverbal signals. We also replicated prior work indicating that children will acquire individual target biases from the observation of biased nonverbal signals. Here we make the case that generalized social group biases can be rapidly and unintentionally transmitted on the basis of observational learning from nonverbal signals. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
Topics: Bias; Child; Child, Preschool; Female; Humans; Male; Nonverbal Communication; Prejudice; Social Behavior
PubMed: 31524429
DOI: 10.1037/pspi0000218 -
American Journal of Primatology Oct 2019The horizontal transmission of pathogenic and beneficial microbes has implications for health and development of socially living animals. Social group is repeatedly...
The horizontal transmission of pathogenic and beneficial microbes has implications for health and development of socially living animals. Social group is repeatedly implicated as an important predictor of gut microbiome structure among primates, with individuals in neighboring social groups exhibiting distinct microbiomes. Here we examine whether group membership is a predictor of gut microbiome structure and diversity across three groups of white-faced capuchins (Cebus capucinus imitator) inhabiting a seasonal Costa Rican forest. We collected 62 fecal samples from 18 adult females during four sampling bouts. Sampling bouts spanned the dry-to-wet-to-dry seasonal transitions. To investigate gut microbial composition, we sequenced the V4 region of the 16S rRNA gene. We used the DADA2 pipeline to assign amplicon sequence variants and the RDP database to classify taxa. Our findings are: 1) gut microbiomes of capuchins clustered by social group in the late dry season, but this pattern was less evident in other sampling bouts; 2) social group was a significant variable in a PERMANOVA test of beta diversity, but it accounted for less variation than season; 3) social group was not an important predictor of abundance for the ten most abundant microbial taxa in capuchins; 4) when examining log2-fold abundances of microbes between social groups, there were significant differences in some pairwise comparisons. While this is suggestive of group-wide differences, individual variation may have a strong impact and should be assessed in future studies. Overall, we found a minor impact of social group membership on the gut microbiota of wild white-faced capuchins. Future research including home range overlap and resource use, as well as fine-scale investigation of individual variation, will further elucidate patterns of socially structured microbes.
Topics: Animals; Biodiversity; Cebus; Costa Rica; Feces; Female; Forests; Gastrointestinal Microbiome; Homing Behavior; RNA, Ribosomal, 16S; Seasons; Sequence Analysis, DNA; Social Environment
PubMed: 31081233
DOI: 10.1002/ajp.22985 -
Biology Letters Jan 2019Choice of social group can affect the likelihood of survivorship and reproduction for social species. By joining larger social groups-shoals-small freshwater fish like...
Choice of social group can affect the likelihood of survivorship and reproduction for social species. By joining larger social groups-shoals-small freshwater fish like the mosquitofish Gambusia affinis can reduce predation risk and forage more efficiently. We tested shoal choice in mosquitofish to determine whether such choices are economically rational, i.e. consistent and optimal. Although many studies of decision-making assume rational choice, irrational decision-making is common and occurs across contexts. We tested rationality of shoaling decisions by testing the constant ratio rule, which states that the relative preference for two options should not change in the presence of a third option. Female mosquitofish upheld this rule when tested for shoal preference based on group size. Our results contrast with other studies showing violations of the constant ratio rule in foraging and mate choice decision-making contexts. These results suggest that decisions that immediately influence survivorship or decision-making along a single dimension may favour rational decision-making.
Topics: Animals; Cyprinodontiformes; Decision Making; Female; Predatory Behavior; Reproduction
PubMed: 30958208
DOI: 10.1098/rsbl.2018.0693 -
Philosophy of the Social Sciences Dec 2017Many existing defenses of group rights seem to rely on the notion of group freedom. To date, however, no adequate analysis of this notion has been offered. Group freedom...
Many existing defenses of group rights seem to rely on the notion of group freedom. To date, however, no adequate analysis of this notion has been offered. Group freedom is best understood in terms of processes of social categorization that are embedded in social mechanisms. Such processes often give rise to group-specific constraints and enablements. On the proposed social mechanism account, group rights are demands for group freedom. Even so, group rights often serve to eradicate individual unfreedom. Furthermore, generic measures sometimes provide the most appropriate solution to a problem of group unfreedom.
PubMed: 30369647
DOI: 10.1177/0048393117726172 -
The Australian and New Zealand Journal... Aug 2022Veterans transitioning to civilian life after leaving the military face unique health concerns. Although there is a significant body of research exploring veterans'...
OBJECTIVE
Veterans transitioning to civilian life after leaving the military face unique health concerns. Although there is a significant body of research exploring veterans' experiences of transition and predictors of well-being, there are limited studies examining how social group engagement influences veterans' transition. We explored how Australian Defence Force veterans' social group engagement and identity influenced their adjustment to civilian life and well-being.
METHODS
Forty Australian veterans (85% male; mean age = 37 years, range = 25-57 years) took part in in-depth, semi-structured interviews. Participants completed two mapping tasks (a social network map and life course map) that provided a visual component to the interviews. Interview transcripts were analysed thematically and interpreted by adopting a social identity approach.
RESULTS
Joining the military involved a process of socialisation into military culture that for most participants led to the development of a military identity. An abrupt or difficult discharge from defence was often associated with a negative impact on social group engagement and well-being in civilian life. Veterans' social group memberships may act not only as positive psychological resources during transition but also as a potential source of conflict, especially when trying to re-engage with civilian groups with different norms or beliefs. Military values inscribed within a veteran's sense of self, including a strong sense of service, altruism and giving back to their community, may operate as positive resources and promote social group engagement.
CONCLUSION
Engaging with supportive social groups can support transition to civilian life. Reintegration may be improved via effective linkage with programmes (e.g. volunteering, ex-service support organisations) that offer supportive social networks and draw upon veterans' desire to give back to community. Social mapping tasks that visualise veterans' social group structures may be useful for clinicians to explore the roles and conflicts associated with veterans' social group memberships during transition.
Topics: Adult; Australia; Female; Humans; Life Change Events; Male; Middle Aged; Military Personnel; Social Networking; Veterans
PubMed: 34541871
DOI: 10.1177/00048674211046894