Cooperative Dilemmas Research Articles

Contact-based model for strategy updating and evolution of cooperation

To establish an available model for the astoundingly strategy decision process of players is not easy, sparking heated debate about the related strategy updating rules is intriguing. Models for evolutionary games have traditionally assumed that players imitate their successful partners by the comparison of respective payoffs, raising the question of what happens if the game information is not easily available. Focusing on this yet-unsolved case, the motivation behind the work presented here is to establish a novel model for the updating of states in a spatial population, by detouring the required payoffs in previous models and considering much more players’ contact patterns. It can be handy and understandable to employ switching probabilities for determining the microscopic dynamics of strategy evolution. Our results illuminate the conditions under which the steady coexistence of competing strategies is possible. These findings reveal that the evolutionary fate of the coexisting strategies can be calculated analytically, and provide novel hints for the resolution of cooperative dilemmas in a competitive context. We hope that our results have disclosed new explanations about the survival and coexistence of competing strategies in structured populations.

Social learning in cooperative dilemmas

Helping is a cornerstone of social organization and commonplace in human societies. A major challenge for the evolutionary sciences is to explain how cooperation is maintained in large populations with high levels of migration, conditions under which cooperators can be exploited by selfish individuals. Cultural group selection models posit that such large-scale cooperation evolves via selection acting on populations among which behavioural variation is maintained by the cultural transmission of cooperative norms. These models assume that individuals acquire cooperative strategies via social learning. This assumption remains empirically untested. Here, I test this by investigating whether individuals employ conformist or payoff-biased learning in public goods games conducted in 14 villages of a forager-horticulturist society, the Pahari Korwa of India. Individuals did not show a clear tendency to conform or to be payoff-biased and are highly variable in their use of social learning. This variation is partly explained by both individual and village characteristics. The tendency to conform decreases and to be payoff-biased increases as the value of the modal contribution increases. These findings suggest that the use of social learning in cooperative dilemmas is contingent on individuals' circumstances and environments, and question the existence of stably transmitted cultural norms of cooperation.

How to learn about teaching: An evolutionary framework for the study of teaching behavior in humans and other animals.

The human species is more reliant on cultural adaptation than any other species, but it is unclear how observational learning can give rise to the faithful transmission of cultural adaptations. One possibility is that teaching facilitates accurate social transmission by narrowing the range of inferences that learners make. However, there is wide disagreement about how to define teaching, and how to interpret the empirical evidence for teaching across cultures and species. In this article I argue that disputes about the nature and prevalence of teaching across human societies and nonhuman animals are based on a number of deep-rooted theoretical differences between fields, as well as on important differences in how teaching is defined. To reconcile these disparate bodies of research, I review the three major approaches to the study of teaching - mentalistic, culture-based, and functionalist - and outline the research questions about teaching that each addresses. I then argue for a new, integrated framework that differentiates between teaching types according to the specific adaptive problems that each type solves, and apply this framework to restructure current empirical evidence on teaching in humans and nonhuman animals. This integrative framework generates novel insights, with broad implications for the study of the evolution of teaching, including the roles of cognitive constraints and cooperative dilemmas in how and when teaching evolves. Finally, I propose an explanation for why some types of teaching are uniquely human, and discuss new directions for research motivated by this framework.

Cooperation in harsh environments and the emergence of spatial patterns

This paper concerns the confluence of two important areas of research in mathematical biology: spatial pattern formation and cooperative dilemmas. Mechanisms through which social organisms form spatial patterns are not fully understood. Prior work connecting cooperation and pattern formation has often included unrealistic assumptions that shed doubt on the applicability of those models toward understanding real biological patterns. I investigated a more biologically realistic model of cooperation among social actors. The environment is harsh, so that interactions with cooperators are strictly needed to survive. Harshness is implemented via a constant energy deduction. I show that this model can generate spatial patterns similar to those seen in many naturally-occuring systems. Moreover, for each payoff matrix there is an associated critical value of the energy deduction that separates two distinct dynamical processes. In low-harshness environments, the growth of cooperator clusters is impeded by defectors, but these clusters gradually expand to form dense dendritic patterns. In very harsh environments, cooperators expand rapidly but defectors can subsequently make inroads to form reticulated patterns. The resulting web-like patterns are reminiscent of transportation networks observed in slime mold colonies and other biological systems.

Cooperation and the evolution of intelligence.

The high levels of intelligence seen in humans, other primates, certain cetaceans and birds remain a major puzzle for evolutionary biologists, anthropologists and psychologists. It has long been held that social interactions provide the selection pressures necessary for the evolution of advanced cognitive abilities (the ‘social intelligence hypothesis’), and in recent years decision-making in the context of cooperative social interactions has been conjectured to be of particular importance. Here we use an artificial neural network model to show that selection for efficient decision-making in cooperative dilemmas can give rise to selection pressures for greater cognitive abilities, and that intelligent strategies can themselves select for greater intelligence, leading to a Machiavellian arms race. Our results provide mechanistic support for the social intelligence hypothesis, highlight the potential importance of cooperative behaviour in the evolution of intelligence and may help us to explain the distribution of cooperation with intelligence across taxa.

The Cooperative Security Dilemma in the Baltic Sea Region

This paper examines a clash between modern and post-modern security systems, which may generate cooperative security dilemmas. Cooperative security dilemmas are not state-centric concepts as traditional security dilemmas but apply to international systems. The variations of cooperative security dilemmas are tested in the context of Baltic Sea regional security complex, particularly the integration dilemma in the Nordic countries and the identity dilemma with Russia. The security and defense postures of some regional actors tend to follow modern security understandings that may produce cooperative security dilemmas in the post-modern security environment.

Vessels and villages: evidence for conformist transmission in early village aggregations on the Pajarito Plateau, New Mexico

Since at least the early 1900s archaeologists have been debating why villages form in the pre-hispanic US Southwest. Less emphasis has been placed on the factors enabling differential persistence of villages, once formed; yet village life poses problems of social coordination. We find that data from a recently excavated Late Coalition period village on the Pajarito Plateau of New Mexico, Burnt Mesa Pueblo, exhibits less diversity in ceramic style than would be expected, if ceramic styles were “neutral,” using as a baseline the ceramic diversity that typifies local hamlets of the Early Coalition period. The evidence suggests that the local transmission processes affecting ceramic design were biased towards conformity (i.e., exhibit frequency-dependent bias). We take conformity in ceramic design to be one symptom of a developing social system that places great value on within-group cooperation, helping alleviate cooperative dilemmas in these early aggregates.

Why People Punish Defectors: Weak Conformist Transmission can Stabilize Costly Enforcement of Norms in Cooperative Dilemmas

In this paper, we present a cultural evolutionary model in which norms for cooperation and punishment are acquired via two cognitive mechanisms: (1) payoff-biased transmission—a tendency to copy the most successful individual; and (2) conformist transmission—a tendency to copy the most frequent behavior in the population. We first show that if a finite number of punishment stages is permitted (e.g. two stages of punishment occur if some individuals punish people who fail to punish non-cooperators), then an arbitrarily small amount of conformist transmission will stabilize cooperative behavior by stabilizing punishment at some n -th stage. We then explain how, once cooperation is stabilized in one group, it may spread through a multi-group population via cultural group selection. Finally, once cooperation is prevalent, we show how prosocial genes favoring cooperation and punishment may invade in the wake of cultural group selection.

The Rotating Credit Association: A "Middle Rung" in Development

The building up of a variety of institutions, serving the purpose of promoting individual savings, and organizing them and making them fruitful to the saver and to the community, should be given a high priority in every development plan. To be effective, the institutions have to be adapted to different individual needs and possibilities and must fit into the community patterns; they must aim at encouraging planned and "goal-directed" savings. Even if, at least in the beginning, the financial results would not constitute more than a trickle of new capital disposal, the effects in rationalizing attitudes and mobilizing ambitions might be crucially important. --Gunnar Myrdal, in An International Economy (p. 360)