Suppose that a large number of individuals are randomly matched into groups where each group plays a finite symmetric game. Individuals breed true according to their individual material payoffs, but the expected number of surviving offspring may depend on the material payoff vector to the whole group. We show that the mean-field equation for the induced population dynamic is equivalent to the r...

Recent work (e.g., Harkins, 1987; Szymanski & Harkins, 1987) has suggested that social loafing occurs because participants' outputs cannot be evaluated by the experimenter, by the coactors, or by the participants themselves. This analysis has focused on the output of the individual, but in loafing research, participants work together to produce a group product. However, in this prior work parti...

This paper is a contribution to the development of an ontology of conflict. In particular, we single out and we study a peculiar notion of group conflict, that we suggestively label ‘social contradiction’. In order to do so, we shall introduce and discuss the methodology of social choice theory, since it allows for defining the notion of collective attitude that may emerge from a number of poss...

Introduction Nature and Formation of Groups Groupthink (Box 7.1) Type of Groups The Minimal Group Paradigm Experiments (Box 7.2) Influence of Group on Individual Behaviour Social Loafing Group Polarisation Conformity, Compliance, and Obedience The Autokinetic Effect (Box 7.3) Group Pressure and Conformity : The Asch Experiment (Box 7.4) Cooperation and Competition Sherif’s Summer Camp Experimen...

Lending to the poor is expensive due to high screening, monitoring, and enforcement costs. Group lending advocates believe lenders overcome this by harnessing social connections. Using data from FINCA-Peru, I exploit a quasi-random group formation process to find evidence of peers successfully monitoring and enforcing joint-liability loans. Individuals with stronger social connections to their ...

Identity is a central concept in the social sciences. In this study, we present a laboratory experiment that measures the effects of induced group identity on participant social preferences. We find that when participants are matched with an ingroup member (as opposed to an outgroup member) they show a 47% increase in charity concerns when they have a higher payoff and a 93% decrease in envy wh...

A collaborative group is commonly defined as a set of agents, which share information and coordinate activities while working towards a common goal. How do groups decide which are their common goals and what to intend? According to the much cited theory of Cohen and Levesque, an agent intends g if it has chosen to pursue goal g and it has committed itself to making g happen. Following the same ...

While modeling group decision making scenarios, the existence of a central authority is often assumed which is in charge of amalgamating the preferences of a given set of agents with the aim of computing a socially desirable outcome, for instance, maximizing the utilitarian or the egalitarian social welfare. Departing from this classical perspective and inspired by the growing body of literatur...

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Identity is a central concept in the social sciences. In this study, we present a laboratory experiment that measures the effects of induced group identity on participant social preferences. We find that when participants are matched with an ingroup member (as opposed to an outgroup member) they show a 47% increase in charity concerns when they have a higher payoff and a 93% decrease in envy wh...