scholarly journals Structure and function in mammalian societies

2009 ◽  
Vol 364 (1533) ◽  
pp. 3229-3242 ◽  
Author(s):  
Tim Clutton-Brock
Keyword(s):  
Life Histories ◽  
Inclusive Fitness ◽  
Group Level ◽  
Eusocial Insects ◽  
Physical Environments ◽  
Dominant Female ◽  
Group Members ◽  
Breeding Groups ◽  
And Function ◽  
Animal Societies

Traditional interpretations of the evolution of animal societies have suggested that their structure is a consequence of attempts by individuals to maximize their inclusive fitness within constraints imposed by their social and physical environments. In contrast, some recent re-interpretations have argued that many aspects of social organization should be interpreted as group-level adaptations maintained by selection operating between groups or populations. Here, I review our current understanding of the evolution of mammalian societies, focusing, in particular, on the evolution of reproductive strategies in societies where one dominant female monopolizes reproduction in each group and her offspring are reared by other group members. Recent studies of the life histories of females in these species show that dispersing females often have little chance of establishing new breeding groups and so are likely to maximize their inclusive fitness by helping related dominants to rear their offspring. As in eusocial insects, increasing group size can lead to a progressive divergence in the selection pressures operating on breeders and helpers and to increasing specialization in their behaviour and life histories. As yet, there is little need to invoke group-level adaptations in order to account for the behaviour of individuals or the structure of mammalian groups.

scholarly journals Repeatable group differences in the collective behaviour of stickleback shoals across ecological contexts

2018 ◽  
Vol 285 (1872) ◽  
pp. 20172629 ◽  
Author(s):  
Jolle W. Jolles ◽  
Kate L. Laskowski ◽  
Neeltje J. Boogert ◽  
Andrea Manica
Keyword(s):  
Collective Behaviour ◽  
Group Level ◽  
Form And Function ◽  
Large Context ◽  
Social Familiarity ◽  
Group Variation ◽  
Group Members ◽  
And Function ◽  
Future Work ◽  
Animal Societies

Establishing how collective behaviour emerges is central to our understanding of animal societies. Previous research has highlighted how universal interaction rules shape collective behaviour, and that individual differences can drive group functioning. Groups themselves may also differ considerably in their collective behaviour, but little is known about the consistency of such group variation, especially across different ecological contexts that may alter individuals' behavioural responses. Here, we test if randomly composed groups of sticklebacks differ consistently from one another in both their structure and movement dynamics across an open environment, an environment with food, and an environment with food and shelter. Based on high-resolution tracking data of the free-swimming shoals, we found large context-associated changes in the average behaviour of the groups. But despite these changes and limited social familiarity among group members, substantial and predictable behavioural differences between the groups persisted both within and across the different contexts (group-level repeatability): some groups moved consistently faster, more cohesively, showed stronger alignment and/or clearer leadership than other groups. These results suggest that among-group heterogeneity could be a widespread feature in animal societies. Future work that considers group-level variation in collective behaviour may help understand the selective pressures that shape how animal collectives form and function.

scholarly journals Longevity suppresses conflict in animal societies

2013 ◽  
Vol 9 (5) ◽  
pp. 20130680 ◽  
Author(s):  
Markus Port ◽  
Michael A. Cant
Keyword(s):  
Social Conflict ◽  
Inclusive Fitness ◽  
Resource Depletion ◽  
Group Conflict ◽  
Group Members ◽  
Animal Societies

Models of social conflict in animal societies generally assume that within-group conflict reduces the value of a communal resource. For many animals, however, the primary cost of conflict is increased mortality. We develop a simple inclusive fitness model of social conflict that takes this cost into account. We show that longevity substantially reduces the level of within-group conflict, which can lead to the evolution of peaceful animal societies if relatedness among group members is high. By contrast, peaceful outcomes are never possible in models where the primary cost of social conflict is resource depletion. Incorporating mortality costs into models of social conflict can explain why many animal societies are so remarkably peaceful despite great potential for conflict.

The Epistemology of Groups

2020 ◽  
Author(s):  
Jennifer Lackey
Keyword(s):  
Group Level ◽  
Social Significance ◽  
Individual Group ◽  
Key Concepts ◽  
Normative Requirements ◽  
Group Members ◽  
The Individual ◽  
Belief Justification ◽  
In Virtue Of ◽  
Trump Administration

Groups are often said to bear responsibility for their actions, many of which have enormous moral, legal, and social significance. The Trump Administration, for instance, is said to be responsible for the U.S.’s inept and deceptive handling of COVID-19 and the harms that American citizens have suffered as a result. But are groups subject to normative assessment simply in virtue of their individual members being so, or are they somehow agents in their own right? Answering this question depends on understanding key concepts in the epistemology of groups, as we cannot hold the Trump Administration responsible without first determining what it believed, knew, and said. Deflationary theorists hold that group phenomena can be understood entirely in terms of individual members and their states. Inflationary theorists maintain that group phenomena are importantly over and above, or otherwise distinct from, individual members and their states. It is argued that neither approach is satisfactory. Groups are more than their members, but not because they have “minds of their own,” as the inflationists hold. Instead, this book shows how group phenomena—like belief, justification, and knowledge—depend on what the individual group members do or are capable of doing while being subject to group-level normative requirements. This framework, it is argued, allows for the correct distribution of responsibility across groups and their individual members.

Pluralistic Ignorance Research in Psychology: A Scoping Review of Topic and Method Variation and Directions for Future Research

2021 ◽  
pp. 108926802199516
Author(s):  
Rikki H. Sargent ◽  
Leonard S. Newman
Keyword(s):  
Scoping Review ◽  
Future Research ◽  
Pluralistic Ignorance ◽  
Group Level ◽  
Conceptual Approach ◽  
Individual Level ◽  
Group Members

Pluralistic ignorance occurs when group members mistakenly believe others’ cognitions and/or behaviors are systematically different from their own. More than 20 years have passed since the last review of pluralistic ignorance from a psychological framework, with more than 60 empirical articles assessing pluralistic ignorance published since then. Previous reviews took an almost entirely conceptual approach with minimal review of methodology, making existing reviews outdated and limited in the extent to which they can provide guidelines for researchers. The goal of this review is to evaluate and integrate the literature on pluralistic ignorance, clarify important conceptual issues, identify inconsistencies in the literature, and provide guidance for future research. We provide a comprehensive definition for the phenomenon, with a focus on its status as a group-level phenomenon. We highlight three areas of variation in particular in the current scoping review: variation in topics assessed, variation in measurement, and (especially) variation in methods for assessing the implications of individual-level misperceptions that, in aggregate, lead to pluralistic ignorance. By filling these gaps in the literature, we ultimately hope to motivate further analysis of the phenomenon.

Socialisation Tactics of the Spectacled Parrotlet (Forpus Conspicillatus)

Behaviour ◽  
1991 ◽  
Vol 119 (1-2) ◽  
pp. 1-29 ◽  
Author(s):  
Kyra Garnetzke-Stollmann ◽  
Dierk Franck
Keyword(s):  
Sexual Behaviour ◽  
Early Stage ◽  
Rank Order ◽  
Host Group ◽  
Pair Bonds ◽  
Group Members ◽  
The One ◽  
And Function ◽  
Sibling Group ◽  
Sibling Groups

AbstractSpectacled parrotlets live in a complex system of individual relationships throughout their lives. The adults form exclusive pair bonds, addressing all friendly and sexual behaviour patterns to each other. Pair mates cooperate in agonistic situations. As long as they stay close together they hold the same rank-order position. In mate-choice experiments females (not males) significantly preferred a mate which formerly held a high social position. There are also non-exclusive pair bonds, which are far less stable than exclusive ones. Only exclusive pairs have a good chance to occupy a breeding cavity. All group members are synchronized in many of their activities, such as foraging, preening or resting. They are keenly interested in unusual activities of other group members. Social learning, including copying sexual techniques, seems to be essential. After fledging the parents keep their offspring at a distance from a very early stage. Instead of a close parent-offspring relationship the fledglings form sibling groups with their nest mates. Over a period of months siblings remain the main interaction partners for all friendly and playful activities. They also support one another in agonistic situations. In the first months of life even courtship feeding and sexual behaviour are addressed predominantly to siblings. Thus a pair-like relationship is established between siblings, anticipating the permanent pair bond of adults. Single fledglings, deprived of the experience of a sibling group, remained poorly integrated into the group. They developed alternative socialisation tactics, namely (1) joining a host group of unrelated siblings, (2) renewing a friendly partnership with the parents, (3) helping to protect and feed younger siblings or even unrelated fledglings and (4) seeking early partnership with unrelated group members. Out of 10 single fledglings only the one that was accepted by a host sibling group immediately after fledging became well integrated into the whole group and reproduced well. It is argued that sibling groups offer good opportunities for learning partnership and function as a safe basis for exploring the social environment. It is tentatively proposed that single fledglings have a decreased probability of reproductive success.

scholarly journals Transcriptomic signatures of ageing vary in solitary and social forms of an orchid bee

2020 ◽  
Author(s):  
Alice C. Séguret ◽  
Eckart Stolle ◽  
Fernando A. Fleites-Ayil ◽  
José Javier G. Quezada-Euán ◽  
Klaus Hartfelder ◽  
...  
Keyword(s):  
Gene Expression ◽  
Juvenile Hormone ◽  
Candidate Genes ◽  
Gene Networks ◽  
Life Histories ◽  
Molecular Mechanisms ◽  
Trade Off ◽  
Eusocial Insects ◽  
Orchid Bee ◽  
Social Forms

AbstractEusocial insect queens are remarkable in their ability to maximise both fecundity and longevity, thus escaping the typical trade-off between these two traits. In species exhibiting complex eusocial behaviour, several mechanisms have been proposed to underlie the remoulding of the trade-off, such as reshaping of the juvenile hormone pathway, or caste-specific susceptibility to oxidative stress. However, it remains a challenge to disentangle the molecular mechanisms underlying the remoulding of the trade-off in eusocial insects from caste-specific physiological attributes that have subsequently arisen due to their different life histories. Socially plastic species such as the orchid bee Euglossa viridissima represent excellent models to address the role of sociality per se in longevity as they allow direct comparisons of solitary and social individuals within a common genetic background. We present data on gene expression and juvenile hormone levels from young and old bees, from both solitary and social nests. We found 940 genes to be differentially expressed with age in solitary females, versus only 14 genes in social dominant females, and seven genes in subordinate females. We performed a weighted gene co-expression network analysis to further highlight candidate genes related to ageing in this species. Primary “ageing gene” candidates were related to protein synthesis, gene expression, immunity and venom production. Remarkably, juvenile hormone titres did not vary with age or social status. These results represent an important step in understanding the proximate mechanisms underlying the remodeling of the fecundity/longevity trade-off that accompanies the evolutionary transition from solitary life to eusociality.Significance statementThe remarkably long lifespan of the queens of eusocial insects despite their high reproductive output suggests that they are not subject to the widespread trade-off between fecundity and longevity that governs solitary animal life histories, yet surprisingly little is known of the molecular mechanisms underpinning their longevity. Using a socially plastic bee in which some individuals of a population are social whilst others are solitary, we identified hundreds of candidate genes and related gene networks that are involved in the remoulding of the fecundity/longevity tradeoff. As well as identifying candidate ageing genes, our data suggest that even in incipient stages of sociality there is a marked reprogramming of ageing; long live the queen.

scholarly journals Relative deprivation and intergroup competition

2010 ◽  
Vol 13 (6) ◽  
pp. 685-700 ◽  
Author(s):  
Nir Halevy ◽  
Eileen Y. Chou ◽  
Taya R. Cohen ◽  
Gary Bornstein
Keyword(s):  
Relative Deprivation ◽  
Prisoner’S Dilemma ◽  
Group Level ◽  
Experimental Paradigm ◽  
Destructive Behavior ◽  
Intergroup Competition ◽  
Group Outcomes ◽  
Group Members ◽  
Collective Efficiency ◽  
Individual Participation

Two experiments utilized a new experimental paradigm—the Intergroup Prisoner’s Dilemma— Maximizing Difference (IPD-MD) game—to study how relative deprivation at the group level affects intergroup competition. The IPD-MD game enables group members to make a costly contribution to either a within-group pool that benefits fellow ingroup members, or a between-group pool, which, in addition, harms outgroup members. We found that when group members were put in a disadvantaged position, either by previous actions of the outgroup (Experiment 1) or by random misfortune (Experiment 2), they contributed substantially more to the competitive between-group pool. This destructive behavior both minimized inequality between the groups and reduced collective efficiency. Our results underscore the conditions that lead group members to care about relative (rather than absolute) group outcomes and highlight the need to differentiate between the motivation to get ahead and the motivation not to fall behind: the latter, it appears, is what motivates individual participation in destructive intergroup competition.

Assessing the Effects of Partisan Bias at the Group Level of Analysis: A Hidden Profile Experiment

2018 ◽  
Vol 47 (6) ◽  
pp. 1283-1302 ◽  
Author(s):  
Brian Manata ◽  
Franklin J. Boster ◽  
Gwen M. Wittenbaum ◽  
Daniel E. Bergan
Keyword(s):  
Decision Making ◽  
Political Ideology ◽  
Group Level ◽  
Political Arena ◽  
Partisan Bias ◽  
Decision Accuracy ◽  
Decision Making Problem ◽  
Group Members ◽  
Hidden Profile ◽  
Level Of Analysis

Although there is some evidence in the political arena that pooling information can overcome individual biases to improve decision-making accuracy, research from the group communication and psychology arenas suggests otherwise. Specifically, research on the hidden profile, a group-level decision-making problem, suggests that groups are decidedly biased when making decisions. This laboratory experiment tested whether or not partisan biases manifest at the group level of analysis. In the main, it was found that groups composed of either all Republican or all Democratic group members were likely to make a decision that was consonant with their party’s political ideology, which ultimately impacted hidden profile solution rates (i.e., decision accuracy). Moreover, supplemental analyses suggest that Republican and Democratic groups reached their biased decisions through different means. A discussion is provided in which the implications of these results are considered.

Behavioural consistency and group conformity in humbug damselfish

Behaviour ◽  
2017 ◽  
Vol 154 (13-15) ◽  
pp. 1343-1359 ◽  
Author(s):  
Alicia L.J. Burns ◽  
Timothy M. Schaerf ◽  
Ashley J.W. Ward
Keyword(s):  
Dominance Rank ◽  
Social Groups ◽  
Null Model ◽  
Group Level ◽  
Absolute Size ◽  
Social Hierarchies ◽  
Behavioural Type ◽  
Level Of Activity ◽  
Group Members ◽  
Dascyllus Aruanus

Abstract Humbug damselfish, Dascyllus aruanus, are a common coral reef fish that form stable social groups with size-based social hierarchies. Here we caught whole wild groups of damselfish and tested whether social groups tended to be comprised of animals that are more similar to one another in terms of their behavioural type, than expected by chance. First we found that individuals were repeatable in their level of activity and exploration, and that this was independent of both absolute size and within-group dominance rank, indicating that animals were behaviourally consistent. Secondly, despite the fact that individuals were tested independently, the behaviour of members of the same groups was significantly more similar than expected under a null model, suggesting that individual behaviour develops and is shaped by conformity to the behaviour of other group members. This is one of the first studies to demonstrate this group-level behavioural conformity in wild-caught groups.

Extensive individual differences of category information in ventral temporal cortex in the congenitally blind

2020 ◽  
Author(s):  
M. Rosenke ◽  
J. Van den Hurk ◽  
E. Margalit ◽  
H. P. Op de Beeck ◽  
K. Grill-Spector ◽  
...  
Keyword(s):  
Individual Differences ◽  
Visual Stimuli ◽  
Large Body ◽  
Temporal Cortex ◽  
Group Level ◽  
Homogeneous Population ◽  
Congenitally Blind ◽  
Functional Representations ◽  
Group Members ◽  
Ventral Temporal Cortex

AbstractHuman ventral temporal cortex (VTC) is a cortical expanse that performs different functions and computations, but is especially critical for visual categorization. Nevertheless, accumulating evidence shows that category-selective regions persist in VTC in the absence of visual experience – for example, in congenitally blind (CB) participants. Despite this evidence, a large body of previous work comparing functional representations in VTC between sighted and CB participants performed univariate analyses at the group level, which assume a homogeneous population – an assumption that has not been formally tested until the present study. Specifically, using fMRI in CB and sighted participants (male and female), we empirically show that at the group level, distributed category representations in VTC are more reliable in the sighted (when viewing visual stimuli) compared to the CB (when hearing auditorily-substituted visual stimuli). Despite these group differences, there is extensive heterogeneity in VTC category representations in the CB to the point that VTC category representations in a subset of CB participants (some who were born without eyes, but not all) are more similar to sighted individuals compared to other CB participants. Together, our findings support a novel idea that driving factors contributing to the formation of VTC category representations in the blind are subject-specific, which complements factors that may generalize across group members. More broadly, the present findings caution conclusions of homogeneity across subjects within a group when performing group neuroimaging analyses without explicitly quantifying individual differences.

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