Inter-individual Interactions Research Articles

A trofolaxes grupal: transtornos narcísicos e reconstruções vinculares

O presente trabalho apresenta um conceito derivado da Biologia do Conhecimento aplicado metaforicamente aos grupos humanos. Trofolaxes denomina o processo de comunicação química utilizado por determinados animais, os insetos sociais, para comunicar uns aos outros as necessidades de sua comunidade, seja em termos de defesa, seja de alimentação ou de reprodução. Aplicada aos grupos, a noção de trofolaxes permite entender determinados mecanismos de regulação grupal pelos quais, através principalmente da linguagem, os indivíduos conseguem produzir a identidade grupal, as fronteiras delimitadoras do grupo e os elementos da dinâmica que possibilitam as interações interindividuais. Se aos insetos, a trofolaxes permite a comunicação, as alterações ontogenéticas e a adaptação filogenética, para os grupos humanos, a trofolaxes simbólica implica na possibilidade da geração da ontogênese específica das distintas psiques, necessárias ao convívio humano.

Gene cluster lock after pheromone receptor gene choice

In mammals, perception of pheromones is based on the expression in each vomeronasal sensory neuron of a limited set of receptor genes, chosen among a large repertoire. Here, we report an extremely tight control of the monogenic and monoallelic transcription of the V1rb2 receptor gene. Combining genetic and electrophysiological approaches, we show that the transcription of a non-functional V1r allele leads to the coexpression of another, functional V1r gene. The choice of this coexpressed gene surprisingly includes genes located on the cluster homologous to the one from which the mutant allele is transcribed. However, V1r genes located in cis relative to the transcribed mutant allele are excluded from the coexpression choice. Our observations strongly suggest a monogenic regulatory mechanism acting (a) at a general level, via the expression of the V1r receptor itself, and (b) at a more local level, defined by the V1r gene cluster.

Interindividual‐intergroup discontinuity as a joint function of acting as a group and interacting with a group

AbstractAn experiment assessed the prisoner's dilemma game (PDG) choices of a set of three persons who interacted with another supposed set of three persons. There were four conditions: (1) group‐on‐group (both three‐person sets constrained by a majority vote), (2) group‐on‐one (only own three‐person set constrained by a majority vote), (3) one‐on‐group (only other three‐person set constrained by a majority vote), (4) one‐on‐one (neither three‐person set constrained by a majority vote). The four conditions were compared with three orthogonal contrasts. Consistent with the assumption that interindividual interactions are less competitive than interactions involving groups, the first contrast indicated that there were fewer competitive choices in the one‐on‐one condition than in the other three conditions pooled. Consistent with the assumption that competitiveness can flow either from acting as a group or interacting with a group, the second contrast found no significant difference between the group‐on‐one and one‐on‐group conditions. Finally, consistent with the assumption that the interindividual‐intergroup discontinuity effect is a joint function of acting as a group and interacting with a group, the third contrast revealed that there were more competitive choices in the group‐on‐group condition than in the one‐on‐group and group‐on‐one conditions pooled. Copyright © 2006 John Wiley & Sons, Ltd.

Modeling and stability analysis of social foraging swarms in multi-obstacle environment

In this article we specify an individual-based foraging swarm (i.e., group of agents) model with individuals that move in an n-dimensional multi-obstacle environment. The motion of each individual (i) is determined by three factors: i) attraction to the local object position (\(\bar x_{io + } \)) which is decided by the local information about the individuals’ position that individual i can find; ii) repulsion from the other individuals on short distances; and iii) attraction to the global object position (xgoal) or repulsion from the obstacles in the environment. The emergent behavior of the swarm motion is the result of a balance between inter-individual interaction and the simultaneous interactions of the swarm members with their environment. We study the stability properties of the collective behavior of the swarm based on Lyapunov stability theory. The simulations show that the swarm can converge to goal regions and diverge from obstacle regions of the environment while maintaining cohesive.

Trust and reciprocity in inter-individual versus inter-group interactions: The effects of social influence, group dynamics, and perspective biases

Using an experimental trust game, I examine whether the perspectives and behavior of group representatives and consensus groups differ from those of the same individuals in an analogous inter-individual situation. A primary goal of this research is to extend past work on trust and reciprocity by examining the impact of the social contexts within which social interactions are characteristically embedded. Specifically, this research concerns whether norms and dynamics of trust and reciprocity differ in the contexts of inter-individual and inter-group interactions. First, I examine whether dynamics of trust and reciprocity differ in various inter-group interactions where inter-group decisions are operationalized as 1) autonomous group representatives, i.e., individuals who are given the responsibility of unilaterally making a decision on behalf of a three-person group engaging with a group representative of another such group; and 2) consensus groups, i.e., group members making a consensus trust or reciprocity decision for their groups via a collective process with another such group. Results of these studies show that 1) people trust less and reciprocate less when responsible for a group or organizational decision as autonomous group representatives; 2) consensus groups do not differ from individuals in their level of trust but show dramatically less reciprocity. The group consensus mechanism in fact produced by far the lowest reciprocity level, significantly lower than that exhibited by either individuals or autonomous group representatives. Thus, inter-group trust and reciprocity dynamics are not readily inferable from their inter-individual counterparts. Moreover, an important implication is emerging here: the extent and direction of the discrepancy between individual and group choices in regard to trust and reciprocity levels and possibly other social preferences in general may depend importantly on the precise details of the group decision-making mechanism, for example whether decisions are made consensually, by majority vote, or by a group leader or representative. In addition to examining the level of trust and reciprocity that occur in these various situations, I also studied, using both behavioral and questionnaire data, the roles of self-interest, social influence, and group dynamics in trust and reciprocity perceptions and behavior. The results showed that there exist discrepancies between behavioral forecasts and the actual behavior, and that trusting behavior is driven strongly by expectation of level of reciprocation, while reciprocating behavior is driven strongly by the difference between trust expectation and actual trust received.

Is the cell phone undermining the social order?: Understanding mobile technology from a sociological perspective

Summary: While conventional mass media (and fixed phones) have primarily supported centralized, formalized organizations , households and other supraindividual systems, cell phones increase the reach and capacity of decentralized, informal systems based on interindividual interactions, thus decelerating or even reversing very long-term evolutionary trends of human society: trends toward stable, depersonalized, formalized, complex and predictable supraindividual institutions.

“Better to be safe than to be sorry”: Extinguishing the individual – group discontinuity effect in competition by cautious reciprocation

The individual – group discontinuity effect entails that in mixed-motive situations, such as the Prisoner's Dilemma game (PDG), intergroup interactions are more competitive than inter-individual interactions. Based on Pruitt and Kimmel's (1977) goal/expectation theory and Axelrod's (1984) cooperation theory, we propose a cautious reciprocation model (CRM), which specifies variables that extinguish or reduce the discontinuity effect by enhancing intergroup cooperation. The model entails that, relative to individuals, the cooperative decisions of the more rational and instrumental group members are more strongly determined by a combination of a concern for long-term greed and a fear of anticipated retaliation, leading them to become more responsive to changes in the PDG task and/or social environment, and to follow an instrumental, cautious reciprocation technique. This technique is measured by increases in the level of cooperation (or competition) shown by groups in reaction to changes in the PDG decisions of the other party, or to experimental manipulations in the PDG task environment (i.e., time perspective, reciprocal strategies, reward structure, sequential vs simultaneous play). A summary of the findings of several earlier Utrecht studies and of recent discontinuity research by Insko, Schopler and co-workers yields evidence for the CRM.

Swarm aggregations using artificial potentials and sliding-mode control

In this paper, we consider a control strategy of multiagent systems, or simply, swarms, based on artificial potential functions and the sliding-mode control technique. First, we briefly discuss a swarm model in n-dimensional space introduced in an earlier paper. In that model, the interindividual interactions are based on artificial potential functions, and the motion of the individuals is along the negative gradient of the combined potential. After that, we consider a general model for vehicle dynamics of each agent (swarm member), and use sliding-mode control theory to force their motion to obey the dynamics of the kinematic model. In this context, the results for the initial model serve as a proof of concept for multiagent coordination and control (swarm aggregation), whereas the present results serve as a possible implementation method for engineering swarms with given vehicle dynamics. The presented control scheme is robust with respect to disturbances and system uncertainties.

Social Networks and Diffusion: Avalanches and Links Evolution

The concept of diffusion is central to every social system, because it underpins the coherence of individuals' behaviour and representations, and hence the coordination of their actions. The idea at the origin of the concept of diffusion is that inter-individual interactions are the driving force behind the evolution of individuals' behaviour, beliefs and representations. Our approach in this paper is based on social influence networks. Agents are embedded in social networks where the advance of influence depends on the propagation of avalanches, giving central importance to the network structure. We consider the noise produced by those avalanches as a characteristic of the social structure that can contribute, through the evolution of links, to transforming the network structure, and hence the dynamics of the diffusion. We then explain why peculiar critical diffusion dynamics emerge, characterised by a power law distribution, instead of the exponential shape of traditional diffusion curves.

Could Species Segregation be a Consequence of Aggregation Processes? Example ofPeriplaneta americana(L.) andP. fuliginosa(Serville)

AbstractOur aim was to show how interindividual interactions, based on specific recognition signals that induce aggregation, can lead to the emergence of a segregation pattern between species. Groups including two cockroach species,Periplaneta americana(L.) (P.a.) andPeriplaneta fuliginosa(Serville) (Dictyoptera: Blattidae) (P.f.) were tested. Behavioural choice tests between two resting sites demonstrated aggregation behaviour in the two species. Aggregation in both species is based on chemical cues.Periplaneta fuliginosahas a higher aggregation level thanP.a.and responds only to its conspecific odour.Periplaneta americanais attracted by the odour of both species presented alone. In the presence of the odours of both species,P.f.selects its own odour, butP.a.neither selects its own odour, nor aggregates under these conditions. This could mean that the perceived chemical signals impair the aggregation process. In mixed groups including larvae of these two species, segregation between species occurs. We assumed that the first species that happened to form an aggregate on one of the resting sites induced the other species to occupy the remaining site. The emergence of a segregation pattern between the two species could be a consequence of the aggregation processes.

Chemosensory Recognition of Olfactory Individuality

Body odors regulate social, sexual and endocrine responses of many species. Specialized structures have evolved to produce and detect odorous signals. Individual identity, often communicated through body odor, can be critical in mate choice, incest avoidance, parental care and other inter-individual interactions. Because of the importance of individual identity, particularly among social species, we have focused our research program on understanding how odors code for individuality and in what contexts individual signals modulate social behavior. In particular, we have been investigating how one set of genes, those of the MHC (see below), are involved in producing an animal’s self odor.

Local population density and the activation of movement in migratory band-forming Mormon crickets

The Mormon cricket, Anabrus simplex (Orthoptera: Tettigoniidae), is a flightless katydid that undergoes major outbreaks in western North America. Under outbreak conditions, Mormon crickets often form large cohesive migratory bands that can contain millions of individuals moving in unison across the landscape. Density-dependent phase polyphenism has been hypothesized as a behavioural mechanism underlying Mormon cricket band formation and movement based largely on the similarity between bands of Mormon crickets and those of migratory locusts. I tested this hypothesis by quantifying the effects of long-term differences in rearing density versus the short-term presence or absence of conspecifics on Mormon cricket movement behaviour across three different developmental stages. Rearing density and the presence of conspecifics both influenced Mormon cricket movement, but in distinctly different ways. Increases in the expression of walking-related behaviours were mainly induced by the short-term presence of conspecifics. The longer-term effects of high rearing density primarily influenced only turning-related behaviours. Developmental variation in activity levels was observed and indicates that developmental stage should be an important consideration in future analyses of Mormon cricket movement. Overall, these results suggest that interindividual interactions play a greater role in inducing the movement of migratory band-forming Mormon crickets than do endogenous behavioural-phase changes mediated by high local rearing density.

Influence sociale et diffusion de l'innovation

The notion of diffusion holds a central place in any social system, because it is at the heart of individuals behaviour or representation phasing, hence of the co-ordination of their actions. The idea at the origin of the notion of diffusion is that inter-individual interactions are the driving forces of the evolution of individuals' behaviours, beliefs and represen-tations. Our approach in this paper is based on social influence networks. Agents are embedded in network structures where the influence advance depends on cumulative effects. First we draw the foundations of a diffusion model based on social influence networks. Then we study the way of propagation of influence trough giving a central importance to the network topology. We consider the noise produced by those avalanches as a characteristic of the social structure that can contribute, by learning effect, to transform the network structure, hence the dynamics of the diffusion. We then explain why peculiar critical diffusion curves do emerge characterized by a power law instead of the exponential form of traditional diffusion curves.

Stability Analysis of Social Foraging Swarms

In this article we specify an M-member "individual-based" continuous time swarm model with individuals that move in an n-dimensional space according to an attractant/repellent or a nutrient profile. The motion of each individual is determined by three factors: i) attraction to the other individuals on long distances; ii) repulsion from the other individuals on short distances; and iii) attraction to the more favorable regions (or repulsion from the unfavorable regions) of the attractant/repellent profile. The emergent behavior of the swarm motion is the result of a balance between inter-individual interactions and the simultaneous interactions of the swarm members with their environment. We study the stability properties of the collective behavior of the swarm for different profiles and provide conditions for collective convergence to more favorable regions of the profile.

A comparison of human aggression committed by groups and individuals: An interindividual–intergroup discontinuity

Experimental research comparing aggressive behavior committed by groups and individuals is important but sparse. This experiment compared aggressive behavior (i.e., amount of hot sauce allocated for others to consume) in four types of interactions: intergroup, interindividual, group-to-individual, and individual-to-group. The results revealed that intergroup interactions were significantly more aggressive than interindividual interactions. In addition, groups allocated and received significantly more hot sauce than individuals. These effects were not explained by diffusion of responsibility or trait aggressiveness. The experiment reveals two noteworthy conclusions: (1) the interindividual–intergroup discontinuity effect extends to aggressive behavior and (2) interactions in which a group is either the source or target of aggression are situational influences that can increase it.

Beyond the group mind: a quantitative review of the interindividual-intergroup discontinuity effect.

This quantitative review of 130 comparisons of interindividual and intergroup interactions in the context of mixed-motive situations reveals that intergroup interactions are generally more competitive than interindividual interactions. The authors identify 4 moderators of this interindividual-intergroup discontinuity effect, each based on the theoretical perspective that the discontinuity effect flows from greater fear and greed in intergroup relative to interindividual interactions. Results reveal that each moderator shares a unique association with the magnitude of the discontinuity effect. The discontinuity effect is larger when (a) participants interact with an opponent whose behavior is unconstrained by the experimenter or constrained by the experimenter to be cooperative rather than constrained by the experimenter to be reciprocal, (b) group members make a group decision rather than individual decisions, (c) unconstrained communication between participants is present rather than absent, and (d) conflict of interest is severe rather than mild.

Longitudinal modelling of respiratory symptoms in children.

A panel of 277 children, aged 3-7 years, was used to study the association between air pollution (O(3), SO(2), NO(2), and total suspended particles), meteorological factors (global radiation, maximum daytime temperature, daily averages of vapour pressure and air humidity) and respiratory symptoms. For 759 days the symptoms were recorded in a diary and modelling was based on a modification of the method proposed by Korn and Whittemore (Biometrics 35: 795-798, 1979). This approach (1) comprises an extension using environmental parameters at different time scales, (2) addresses the suitability of using the daily fraction of symptomatic individuals to account for inter-individual interactions and (3) enables the most significant weather effects to be identified. The resulting model consisted of (1) an individual specific intercept that takes account of the population's heterogeneity, (2) the individual's health status the day before, (3) a long-term meteorological effect, which may be either the squared temperature or global radiation in interaction with temperature, (4) the short-term effect of sulfur dioxide, and (5) the short-term effect of an 8-h ozone concentration above 60 microg/m(3). Using the estimated parameters as input to a simulation study, we checked the quality of the model and demonstrate that the annual cycle of the prevalence of respiratory symptoms is associated to atmospheric covariates. Individuals suffering from allergy have been identified as a group of a particular susceptibility to ozone. The duration of respiratory symptoms appears to be free of scale and follows an exponential distribution function, which confirms that the symptom record of each individual follows a Poisson point-process. This supports the assumption that not only respiratory diseases, but also respiratory symptoms can be considered an independent measure for the health status of a population sample. Since a point process is described by only one parameter (namely the intensity of the point process), it is appropriate for records of respiratory symptoms to identify only one model which covers both the occurrence and duration of symptoms.

Self-organization in relation to several similar concepts: are the boundaries to self-organization indistinct?

Self-organization is a concept and phenomenon whereby system-level patterns spontaneously arise solely from interactions among subunits of the system. Focusing on self-organization at the organismal level, I ask the question: are the boundaries to self-organization indistinct? After reviewing a number of published definitions of self-organization, I explore the conceptual boundaries among self-organization and two similar concepts, stigmergy and self-assembly. I highlight borderline cases that may blur the distinction among these and suggest that they may indeed be conceptually indistinct and difficult to separate in practice. Consequently, I propose a classification scheme based upon three aspects: whether the stimuli to which individuals respond are quantitative or qualitative, whether positive feedback is involved, and whether interindividual interactions are direct or indirect (stigmergic). In addition, I consider several other issues about self-organization, including (1) could a self-organized system use global information? (2) what is the role of the degree of correlation of activity among individuals? and (3) what is the role of positive feedback?

Toward a Reconciliation of Diverging Perspectives on Interindividual-Intergroup Discontinuity: The Role of Procedural Interdependence

This experiment investigated the effect of procedural interdependence on interindividual–intergroup discontinuity (i.e., the tendency within mixed-motive situations for intergroup interactions to be more competitive than interindividual interactions) in Dutch and U.S. college populations. Groups composed of members who were procedurally interdependent, groups composed of members who were procedurally independent, and individuals interacted with a programmed other on three trials of a Prisoner's Dilemma Game. Results across trials indicate that procedurally interdependent group members were more competitive than pooled procedurally independent group members and individuals. The latter two conditions did not differ significantly. No significant effects involving participant nationality were observed. We propose that these findings reconcile diverging perspectives on interindividual–intergroup discontinuity.

The role of age in temporal polyethism in a primitively eusocial wasp

The relation of age to division of labor was assessed in a primitively eusocial wasp, Ropalidia marginata. The performance of four functionally significant tasks was analyzed. It was found that age has a definite correlation with division of labor, since wasps performed tasks in a distinct sequence in their life with successive tasks being initiated at significantly older ages. Age of a wasp was measured in absolute terms and also relative to other individuals in the colony. Probability of performance of a given task relative to other tasks (PTP) and absolute rates at which tasks were performed per unit time (FTP) both showed clear age-dependent patterns, confirming the association of age with division of labor. The proportion of variance explained for both PTP and FTP was significantly higher with relative age than with absolute age. Interindividual interactions were found to be a potential mechanism through which wasps can determine their relative age. The advantages of work organization depending on relative age and the constraints imposed by absolute age are discussed.