Preference Evolution and Reciprocity

This paper provides an evolutionary theory of reciprocity as an aspect of preference interdependence. It is shown that reciprocal preferences, which place negative weight on the payoffs of materialists and positive weight on the payoffs of sufficiently altruistic individuals can invade a population of materialists in a class of aggregative games under both individual selection and random matching. Such preferences are efficiency-reducing when they are rare and efficiency-enhancing when they are widespread, suggesting that they can persist even under group selection and assortative matching. In comparison with simpler specifications of preference interdependence (such as pure altruism or envy), the survival of such preferences is therefore less sensitive to details of the evolutionary selection process.Reciprocity, Evolution, Preference Interdependence

Reciprocity, Materialism and Welfare: An Evolutionary Model

This paper analyses preference evolution in a bargaining situation. We show that preferences for reciprocity, that sustain a conflict-free outcome, are viable if players have enough information about opponents’ preferences. However, depending on the initial starting point, preference evolution can in general both enhance or reduce subjective and material welfare, relative to the situation where all players have the usual materialistic preferences.Preference evolution; Reciprocity; Altruism; Materialism; Subjective and material eciency; Bargaining; Indirect evolutionary approach

Carrot or Stick? Group Selection and the Evolution of Reciprocal Preferences

This paper studies the evolution of both characteristics of reciprocity - the willingness to reward friendly behavior and the willingness to punish hostile behavior. Firstly, preferences for rewarding as well as preferences for punishing can survive evolution provided individuals interact within separated groups. This holds even with randomly formed groups and even when individual preferences are unobservable. Secondly, preferences for rewarding survive only in coexistence with self-interested preferences. But preferences for punishing tend either to vanish or to dominate the population entirely. Finally, the evolution of preferences for rewarding and the evolution of preferences for punishing influence each other decisively. The existence of rewarders enhances the evolutionary success of punishers, but punishers crowd out rewarders

The Evolution of Social Norms and Individual Preferences

Why does an altruistically inclined player behave altruistically in some contexts and egoistically or spitefully in others? This article provides an economic explanation to this question. The basic argument is centered on the idea that social norms shape our preferences through a process of cultural learning. In particular, we claim that, in contexts with a stable norm of reciprocity, an altruistic player can respond in kind to egoistic or spiteful players by behaving either egoistically or spitefully when confronting them and yet continue to be an altruistic player. This is why, instead of studying the evolution of preferences as such, in this work we analyze the evolution of social norms that indirectly determine individual preferences and behavior. Such a study requires that we distinguish between players' behavioral preferences, or those individuals show with their behavior, and players' intrinsic preferences, or those they inherently support or favor. We argue that, whereas the former can change through the evolution of social norms, in this case a reciprocity norm, the latter are not subject to evolutionary pressures and, therefore, we assume them to be given.Social norms, reciprocity, endogenous preferences, asymmetric evolutionary game

Why and How Identity Should Influence Utility

This paper provides an argument for the advantage of a preference for identity-consistent behaviour from an evolutionary point of view. Within a stylised model of social interaction, we show that the development of cooperative social norms is greatly facilitated if the agents of the society possess a preference for identity consistent behaviour. As cooperative norms have a positive impact on aggregate outcomes, we conclude that such preferences are evolutionarily advantageous. Furthermore, we discuss how such a preference can be integrated in the modelling of utility in order to account for the distinctive cooperative trait in human behaviour and show how this squares with the evidence

Reciprocity - an indirect evolutionary analysis

This paper investigates strategic interaction between rational agents whose preferences evolve over time. Players face a pecuniary �game of life� comprising the ultimatum game and the dictator game. Utility may but need not be attached to the reciprocation of fair and unfair play by the opponent and equitable payoff distributions as proposed by Falk and Fischbacher (2001). Evolutionary fitness is determined solely by material success � regardless of the motives for its achievement. Agents cannot explicitly condition the social component of their preferences on whether they face the ultimatum or dictator game. Under these conditions, agents develop a strong preference for reciprocation but little interest in an equitable distribution as such. This corresponds to equitable ultimatum offers but full surplus appropriation by dictators. Adding an exogenous constraint on the possible divergence between preference for reciprocation and for an equitable distribution either makes ultimatum divisions asymmetric or dictators become generous depending on the relative frequency of ultimatum and dictator interaction.

Pathways to social evolution: reciprocity, relatedness, and synergy

Many organisms live in populations structured by space and by class, exhibit plastic responses to their social partners, and are subject to non-additive ecological and fitness effects. Social evolution theory has long recognized that all of these factors can lead to different selection pressures but has only recently attempted to synthesize how these factors interact. Using models for both discrete and continuous phenotypes, we show that analyzing these factors in a consistent framework reveals that they interact with one another in ways previously overlooked. Specifically, behavioral responses (reciprocity), genetic relatedness, and synergy interact in non-trivial ways that cannot be easily captured by simple summary indices of assortment. We demonstrate the importance of these interactions by showing how they have been neglected in previous synthetic models of social behavior both within and between species. These interactions also affect the level of behavioral responses that can evolve in the long run; proximate biological mechanisms are evolutionarily stable when they generate enough responsiveness relative to the level of responsiveness that exactly balances the ecological costs and benefits. Given the richness of social behavior across taxa, these interactions should be a boon for empirical research as they are likely crucial for describing the complex relationship linking ecology, demography, and social behavior.Comment: 4 figure

Coevolution of Cooperation and Partner Rewiring Range in Spatial Social Networks

In recent years, there has been growing interest in the study of coevolutionary games on networks. Despite much progress, little attention has been paid to spatially embedded networks, where the underlying geographic distance, rather than the graph distance, is an important and relevant aspect of the partner rewiring process. It thus remains largely unclear how individual partner rewiring range preference, local vs. global, emerges and affects cooperation. Here we explicitly address this issue using a coevolutionary model of cooperation and partner rewiring range preference in spatially embedded social networks. In contrast to local rewiring, global rewiring has no distance restriction but incurs a one-time cost upon establishing any long range link. We find that under a wide range of model parameters, global partner switching preference can coevolve with cooperation. Moreover, the resulting partner network is highly degree-heterogeneous with small average shortest path length while maintaining high clustering, thereby possessing small-world properties. We also discover an optimum availability of reputation information for the emergence of global cooperators, who form distant partnerships at a cost to themselves. From the coevolutionary perspective, our work may help explain the ubiquity of small-world topologies arising alongside cooperation in the real world

A Dynamic Model of Reciprocity with Asymmetric Equilibrium Payoffs

We analyze indirect evolutionary two-player games to identify the dynamic emergence of (strong) reciprocity in a large number of economic settings. The underlying evolutionary environment allows for an arbitrary initial population state provided that every degree of the compact space of reciprocity is adherent to at least one individual of the corresponding continuum population. The basic results, which essentially maintain the evolutionary viability of reciprocity, are, in several directions, context dependent, and minimum valid for the wide class of evolutionary dynamics which hold for regularity and payoff-monotonicity. The evolutionary solution concept which is applied to elevate the explanatory power of emerging Nash equilibria is dominance solvability, in this case, for continuous strategy spaces. An asymmetric aspect comes into play since the actions of the evolutionary players are not only determined by the current state of reciprocity but also by their inherent, context-free preferences towards others which differ among one another devoid of being endogenized in the time span of the dynamic process at hand.reciprocity, evolutionary game theory, dominance solvability, asymmetric game setting, payoff-monotonic dynamics