How selfish does our evolutionary history suggest that humans will be? We explore models in which groups are formed and dissolved and where reproduction of individuals is determined by their payoffs in a game played within groups. If groups are formed “randomly”and reproductive success of group founders is determined by a multi-person prisoners ’ dilemma game, then selfish behavior will prevail over maximization of group payoffs. However, interesting models exist in which “group selection”sustains cooperative behavior. Forces that support cooperative behavior include assortative matching in groups, group longevity, and punishment-based group norms. “A selector of sufficient knowledge and power might perhaps obtain from the genes at present available in the human species a race combining an average intellect equal to that of Shakespeare with the stature of Carnera. But he could not produce a race of angels. For the moral character or for the wings he would have to await or produce suitable mutations.”... J.B.S. Haldane (Haldane 1932), p. 110

A reconceptualization of stigma is presented that changes the emphasis from the devaluation of an individual's identity to the process by which individuals who satisfy certain criteria come to be excluded from various kinds of social interactions. The authors propose that phenomena currently placed under the general rubric of stigma involve a set of distinct psychological systems designed by natural selection to solve specific problems associated with sociality. In particular, the authors suggest that human beings possess cognitive adaptations designed to cause them to avoid poor social exchange partners, join cooperative groups (for purposes of between-group competition and exploitation), and avoid contact with those who are differentially likely to carry communicable pathogens. The evolutionary view contributes to the current conceptualization of stigma by providing an account of the ultimate function of Stigmatization and helping to explain its consensual nature.

In this paper we examine the effects of the emergence of a new replicator, memes, on the evolution of a pre-existing replicator, genes. Using a version of the NKCS model we examine the effects of increasing the rate of meme evolution in relation to the rate of gene evolution, for various degrees of interdependence between the two replicators. That is, the effects of memes' (suggested) more rapid rate of evolution in comparison to that of genes is investigated using a tunable model of coevolution. It is found that, for almost any degree of interdependence between the two replicators, as the rate of meme evolution increases, a phase transition-like dynamic occurs under which memes have a significantly detrimental effect on the evolution of genes, quickly resulting in the cessation of effective gene evolution. Conversely, the memes experience a sharp increase in benefit from increasing their rate of evolution. We then examine the effects of enabling genes to reduce the percentage of gene-detrimental evolutionary steps taken by memes. Here a critical region emerges as the comparative rate of meme evolution increases, such that if genes cannot effectively select memes a high percentage of the time, they suffer from meme evolution as if they had almost no selective capability. 2 1.

Abstract not found

commitment, conscientiousness, costly signaling theory, equilibrium selection, emotion, empathy, ethics, evolutionary psychology, fitness indicators, genetic correlations, good genes, good parents, good partners, human courtship, kin selection, kindness, individual differences, intelligence, mate choice, mental health, moral virtues, mutation load, mutual choice, person perception, personality, reciprocal altruism, sexual fidelity, sexual selection, social cognition, virtue ethics “Human good turns out to be the activity of the soul exhibiting excellence.” Aristotle (350 BC) Moral evolution theories have emphasized kinship, reciprocity, group selection, and equilibrium selection. Yet, moral virtues are also sexually attractive. Darwin suggested that sexual attractiveness may explain many aspects of human morality. This paper updates his argument by integrating recent research on mate choice, person perception, individual differences, costly signaling, and virtue ethics. Many human virtues may have evolved in both sexes through mutual mate choice to advertise good genetic quality, parenting abilities, and/or partner traits. Such virtues may include kindness, fidelity, magnanimity, and heroism, as well as quasi-moral traits like conscientiousness, agreeableness, mental health, and intelligence. This theory leads to many testable predictions about the phenotypic features, genetic bases, and social-cognitive responses to human moral virtues. A

In this paper we study the evolution of function-valued traits for cooperation in environments that display varying degrees of population viscosity. Traits measure an individual’s intrinsic propensity to cooperate in a standard bilateral Prisoner’s dilemma and can be increasing, decreasing or constant functions of the probability to interact with individuals of ones own genotype. We first analyse adaptation to homogenous environments (with constant degree of viscosity). Comparing environments characterized by different degrees of viscosity, we find that the relation between viscosity and the equilibrium type distribution is not monotone. In fact, it is possible that in fluid populations (no viscosity) there is more cooperation in equilibrium than in populations with intermediate degrees of viscosity. In a second step we analyse heterogenous environments (with varying degrees of viscosity). We find that under very weak assumptions on the distribution of the viscosity parameter strictly increasing functions are always selected and under some parameter constellations they are uniquely so.

We consider a population of players playing a Prisoners' Dilemma Game in a local interaction setting, using a formalism of automata networks. Sufficient conditions for existence of an equilibrium where cooperation coexists with noncooperation (a mixed equilibrium) are derived and properties of an equilibrium are discussed. In a mixed equilibrium the highest payoff will be obtained by a cooperator. For a special one-dimensional case the equilibrium set is fully characterized. We further consider a model where agents can choose (to some extent) whom of their neighbors they want to play with. Results of computer simulations are reported. The most striking feature of simulations is the fact that very organized structures can be observed starting with completely random initial conditions.

A population of individuals is divided into groups. Individuals are recurrently randomly matched with individuals from their group to play a generic symmetric 2-player game. Deterministic inter- and intragroup dynamics are derived from a model of individual imitation within groups and individual migration between groups. Conditions are identified under which subsets (components) of the set of stationary states are (interior) asymptotically stable. The results are then applied to generic coordination games and the prisoners ’ dilemma. The unique asymptotically stable set of stationary states in coordination games is such that every individual in non-extinct groups plays the Paretooptimal equilibrium. In the multi-group prisoners ’ dilemma there is no asymptotically stable subset of the set of stationary states.

this paper we want to convince you that population thinking, not natural selection, is the key to conceptualizing culture in terms of material causes. This argument is based on three well-established facts: 1. There is persistent cultural variation among human groups. Any explanation of human behavior must account for how this variation arises and how it is maintained. 2. Culture is information stored in human brains. Every human culture contains vast amounts of information. Important components of this information are stored in human brains. 3. Culture is derived. The psychological mechanisms that allow culture to be transmitted arose in the course of hominid evolution. Culture is not simply a byproduct of intelligence and social life. Most culture is information stored in human brains---information that got into those brains by various mechanisms of social learning. It follows that to explain the distribution of information stored in the brains of the members of current generation, any coherent theory will have to account for the cultural information in the brains of the previous generation. The theory will also have to explain how this information, together with genes, and environmental contingencies caused the present generation to acquire the cultural information that it did. Unfortunately, we do not understand how this process works. It may be that cultural information stored in brains takes the form of discrete memes that are replicated faithfully in each subsequent generation, or it may not. This is an empirical question which at present is unanswered, and we will see that other models are possible. In every case, the Darwinian population approach will illuminate the process by which the cultural information that is stored in a population of brains is transfor...

An evolutionary model is used to examine how the presence of strategic risk and exclusion in interactions on the basis of economic class differences (assortative matching) can explain persistent inequality. A large population of agents is matched asynchronously according to a wealth-weighted probability distribution to play a 2 \Theta 2 coordination game with a Pareto dominant equilibrium and a risk dominant equilibrium. Best response dynamics eventually select the inferior equilibrium, but with sufficiently strong exclusion inequality arises and persists for arbitrarily long finite periods. In particular, For helpful converstions and comments on previous versions I am grateful to Kim-Sau Chung, Neal Crocker, Ray Deneckere, Steven Durlauf, Grigory Kosenok, William Sandholm, and especially Larry Samuelson for his advice and encouragement. I also thank participants of the 1998 Santa Fe Institute Graduate Workshop in Computational Economics for helpful comments. I am responsible f...