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Cooperative Groups (cooperative + groups)
Selected AbstractsEmergence and Consequences of Division of Labor in Associations of Normally Solitary Sweat BeesETHOLOGY, Issue 4 2009C. Tate Holbrook Division of labor is a pervasive feature of animal societies, but little is known about the causes or consequences of division of labor in non-eusocial cooperative groups. We tested whether division of labor self-organizes in an incipient social system: artificially induced nesting associations of the normally solitary sweat bee Lasioglossum (Ctenonomia) NDA-1 (Hymenoptera: Halictidae). We quantified task performance and construction output by females nesting either alone or with a conspecific. Within pairs, a division of labor repeatedly arose in which one individual specialized on excavation and pushing/tamping while her nestmate guarded the nest entrance. Task specialization could not be attributed to variation in overall activity, and the degree of behavioral differentiation was greater than would be expected due to random variation, indicating that division of labor was an emergent phenomenon generated in part by social dynamics. Excavation specialists did not incur a survival cost, in contrast to previous findings for ant foundress associations. Paired individuals performed more per capita guarding, and pairs collectively excavated deeper nests than single bees , potential early advantages of social nesting in halictine bees. [source] Informational intra-group influence: the effects of time pressure and group sizeEUROPEAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 1 2008Bryan L. Bonner The judgments of groups have immense impact on our daily lives. This paper theorizes that three families of intra-group influence affect the collective estimation process. These different forms of influence map to different levels of task demonstrability, or the extent to which correct answers are transparent to problem-solvers. When demonstrability is low, group estimates are disproportionately influenced by proposals closer to the intra-group mean (centrality). When demonstrability is high and groups are small, group decisions are disproportionately influenced by proposals closer to the correct answer (accuracy). Finally, when demonstrability is high and groups are larger, group decisions are disproportionately influenced by proposals offered by generally more accurate individuals across a set of judgments (expertise). Three laboratory studies support our predictions with regard to informational influence in cooperative groups. Copyright © 2006 John Wiley & Sons, Ltd. [source] The sociobiology of biofilmsFEMS MICROBIOLOGY REVIEWS, Issue 1 2009Carey D. Nadell Abstract Biofilms are densely packed communities of microbial cells that grow on surfaces and surround themselves with secreted polymers. Many bacterial species form biofilms, and their study has revealed them to be complex and diverse. The structural and physiological complexity of biofilms has led to the idea that they are coordinated and cooperative groups, analogous to multicellular organisms. We evaluate this idea by addressing the findings of microbiologists from the perspective of sociobiology, including theories of collective behavior (self-organization) and social evolution. This yields two main conclusions. First, the appearance of organization in biofilms can emerge without active coordination. That is, biofilm properties such as phenotypic differentiation, species stratification and channel formation do not necessarily require that cells communicate with one another using specialized signaling molecules. Second, while local cooperation among bacteria may often occur, the evolution of cooperation among all cells is unlikely for most biofilms. Strong conflict can arise among multiple species and strains in a biofilm, and spontaneous mutation can generate conflict even within biofilms initiated by genetically identical cells. Biofilms will typically result from a balance between competition and cooperation, and we argue that understanding this balance is central to building a complete and predictive model of biofilm formation. [source] Group Identification: The Influence of Group Membership on Retail Hardware Cooperative Members' PerceptionsJOURNAL OF SMALL BUSINESS MANAGEMENT, Issue 2 2004Leslie McClintock Stoel Due to the increasing popularity of retail cooperatives in hardware retailing, a new competitive dynamic has emerged, a hybrid of intratype/intergroup competition. Individual members of one cooperative group now fight for market share with one or more members of competing cooperative groups, in an effort to attain individual goals, as well as group goals. A model of competition that includes both individual and group conditions was tested. Results of the structural equation model (SEM) show that the data fit the theoretical model well (,2=12.414, 8 df, p=0.134, NFI=0.990, NNFI=0.993, CFI=0.996). Our results indicate that, for members of cooperative groups, feelings of identification with the cooperative group resulted in increased perceptions of conflict with a rival who was a member of a competing cooperative and that feelings of group identification influenced beliefs about the importance of competitive behaviors relative to that rival. [source] | ||||||||||