Retaliation and the role for punishment in the evolution of cooperation

Between-Level Incongruences in Human Positivity

Humans now understand the world as multilevel in nature. For example, societies emerge from individuals, and general experiences of life consist of specific aspects and momentary episodes. A critical feature of multilevel phenomena is between-level incongruences. Applied to human positivity, this means that positive higher-level units are not simply composed of positive lower-level units and that what is good for lower-level units may not be good for higher-level units (and vice versa). For example, killjoys may improve societal well-being, personal achievement may require giving up on certain goals, and a happy life may not arise from simply happy moments. In this article, I provide examples (organized by the positive outcome of well-being and performance and by the social, structural, and temporal forms of multilevel phenomena) to show that such between-level incongruences are ubiquitous. Next, I analyze a few mechanisms that may govern the diverse instantiations of between-level incongruences in positivity. Finally, I discuss implications of this perspective, such as why positivity claims should always qualify their level of analysis; how psychological science may benefit from a multilevel, dynamical, and computational perspective; and how to improve human positivity in light of between-level incongruences.

Competition and cooperation among different punishing strategies in the spatial public goods game

Inspired by the fact that people have diverse propensities to punish wrongdoers, we study a spatial public goods game with defectors and different types of punishing cooperators. During the game, cooperators punish defectors with class-specific probabilities and subsequently share the associated costs of sanctioning. We show that in the presence of different punishing cooperators the highest level of public cooperation is always attainable through a selection mechanism. Interestingly, the selection does not necessarily favor the evolution of punishers who would be able to prevail on their own against the defectors, nor does it always hinder the evolution of punishers who would be unable to prevail on their own. Instead, the evolutionary success of punishing strategies depends sensitively on their invasion velocities, which in turn reveals fascinating examples of both competition and cooperation among them. Furthermore, we show that under favorable conditions, when punishment is not strictly necessary for the maintenance of public cooperation, the less aggressive, mild form of sanctioning is the sole victor of the selection process. Our work reveals that natural strategy selection cannot only promote, but sometimes also hinders competition among prosocial strategies.