The evolution of peace (and war) is driven by an elementary social interaction mechanism.

Here we revise Glowacki's model by proposing a simple and empirically tested mechanism that is applicable to a comprehensive set of social interactions. This parsimonious mechanism accounts for the choice of both cooperative and peaceful alternatives and explains when each choice benefits the interacting parties. It is proposed that this mechanism is key to the evolution of both peace and conflict.

The effect of similarity perceptions on human cooperation and confrontation.

By assuring aversive actions are followed by similarly aversive reactions, legislators of antiquity aimed to reduce belligerence and aggression. In the present study we show how similarity perceptions drive cooperation and confrontation across several strategic decision types. Examining the choices made in three one-shot symmetric conflict games: the prisoner's dilemma, the chicken, and the battle of the sexes, we show how a short encounter with a stranger accounts for the formation of subjective similarity perceptions, which together with the expected payoffs of the game determine the choice of the preferred alternative. We describe the role of similarity perceptions for all two-by-two games, specifically for a subset of fifty-seven games that are sensitive to similarity perceptions with the opponent. We then suggest that this mechanism, by which individuals maximize expected payoffs, is key to the understanding of the evolution of cooperation and confrontation.

Extending the two faces of subjective randomness: From the gambler's and hot-hand fallacies toward a hierarchy of binary sequence perception.

In this study, we examined perceptions of binary sequences under uncertainty in an attempt to depict a holistic and unifying framework. The first experiment applied a projection method that motivated participants to observe binary series and provide descriptions of their possible underlying mechanisms or processes. This procedure revealed four distinct perceptual categories: two previously studied categories of chance mechanisms and human performance, associated with the gambler's and hot-hand fallacies, and two newly identified categories-periods and processes and traits and preferences. The next three experiments tested the associations between the four categories and the alternation rates of the observed sequences under three categorical decisions structures: screening, discrimination, and classification. The results reveal the relativity of binary sequence perception. They show that the categories of chance mechanisms and periods and processes reflected rather stable perception across all tested conditions, whereas the other two categories were more susceptible to the context in which they were embedded. The findings support previous research on the gambler's fallacy and show that the hot-hand fallacy is confined to comparisons of human performance and chance mechanisms. A proposed developmental hierarchy suggests that all four categories embody basic cognitive structures that assist in detecting, decoding, and interpreting both inanimate and social aspects of the environment.