Counterpunishment revisited: an evolutionary approach

Evolutionary game theory has shown that in environments characterised by a social-dilemma situation punishment may be an adaptive behaviour. Experimental evidence closely corresponds to this finding but yields contradictory results on the cooperation-enhancing effect of punishment if players are allowed to retaliate against their punishers. The present study sets out to examine the question of whether cooperation will still be part of an evolutionary stable strategy if we allow for counterpunishment opportunities in a theoretic model and tries to reconcile the seemingly contradictory findings from the laboratory. We find that the apparent contradictions can be explained by a difference in the number of retaliation stages employed (one vs many) and even small differences in the degree of retaliativeness.Public goods; Strong reciprocity; Conformism; Counter-punishment; Evolution of behavior

Emergence of social networks via direct and indirect reciprocity

Many models of social network formation implicitly assume that network properties are static in steady-state. In contrast, actual social networks are highly dynamic: allegiances and collaborations expire and may or may not be renewed at a later date. Moreover, empirical studies show that human social networks are dynamic at the individual level but static at the global level: individuals' degree rankings change considerably over time, whereas network-level metrics such as network diameter and clustering coefficient are relatively stable. There have been some attempts to explain these properties of empirical social networks using agent-based models in which agents play social dilemma games with their immediate neighbours, but can also manipulate their network connections to strategic advantage. However, such models cannot straightforwardly account for reciprocal behaviour based on reputation scores ("indirect reciprocity"), which is known to play an important role in many economic interactions. In order to account for indirect reciprocity, we model the network in a bottom-up fashion: the network emerges from the low-level interactions between agents. By so doing we are able to simultaneously account for the effect of both direct reciprocity (e.g. "tit-for-tat") as well as indirect reciprocity (helping strangers in order to increase one's reputation). This leads to a strategic equilibrium in the frequencies with which strategies are adopted in the population as a whole, but intermittent cycling over different strategies at the level of individual agents, which in turn gives rise to social networks which are dynamic at the individual level but stable at the network level

Strong Reciprocity, Human Cooperation and the Enforcement of Social Norms

This paper provides strong evidence challenging the self-interest assumption that dominates the behavioral sciences and much evolutionary thinking. The evidence indicates that many people have a tendency to voluntarily cooperate, if treated fairly, and to punish non-cooperators. We call this behavioral propensity ‘strong reciprocity’ and show empirically that it can lead to almost universal cooperation in circumstances in which purely self-interested behavior would cause a complete breakdown of cooperation. In addition, we show that people are willing to punish those who behaved unfairly towards a third person or who defected in a Prisoner’s Dilemma game with a third person. This suggests that strong reciprocity is a powerful device for the enforcement of social norms like, e.g., food-sharing norms or collective action norms. Strong Reciprocity cannot be rationalized as an adaptive trait by the leading evolutionary theories of human cooperation, i.e., by kin selection theory, reciprocal altruism theory, indirect reciprocity theory and costly signaling theory. However, multi-level selection theories and theories of cultural evolution are consistent with strong reciprocity.Strong Reciprocity, Punishment, Evolution, Human Cooperation, Social Norms

Gossip for social control in natural and artificial societies

In this work we propose a theory of gossip as a means for social control. Exercising social control roughly means to isolate and to punish cheaters. However, punishment is costly and it inevitably implies the problem of second-order cooperation. Moving from a cognitive model of gossip, we report data from ethnographic studies and agent-based simulations to support our claim that gossip reduces the costs of social control without lowering its efficacy

An Experimental Analysis of the Ultimatum Game: The Role of Competing Motivations

This paper forwards a new way of accounting for the experimental evidence related to the Ultimatum Game. We argue that players in this game have reasons to be both fair and self-interested, but the balance between these two considerations cannot be expressed in terms of a tradeoff. We test our thesis by perturbing the Ultimatum Game in a way that emphasizes the force of self-interest considerations; the evidence we collected provides support for our thesis.

Sequence Matters: an Experimental Study of the Effects of Experiencing Positive and Negative Reciprocity

This paper presents an experimental analysis of people’s behavior in situations involving both positive and negative reciprocity. The experiment implements sequences of two types of extensive form games called Punishment games and Trust games. The contemporaneous use of these two types of games allows us to define an ideal framework for understanding the basic elements of reciprocal behavior. Results show that the level of trust and punishment are consistent with the view that emotions are involvedReciprocity, trust, intentions, emotions, experiments J.E.L. Classification: D63, C78, C91