No abstract

No abstract

Why are humans so vulnerable to pain in interpersonal relations and can so easily hurt others physically and emotionally? We theoretically examine whether being offensively strong but defensively weak can evolve as a strategic trait that fosters cooperation. We study a population comprised of "thick-skinned" and "thinskinned" agents by using an indirect evolution model that combines rational choice in strategic interactions with evolutionary selection across generations. We find that (a) the relatively vulnerable and cooperative thin-skins cannot evolve under purely random matching, (b) with some assortment thin-skins evolve and can take over the entire population, (c) vulnerability to greater pain makes it easier for thin-skins to evolve, and (d) proximate pain which merely feels bad but does not lower fitness helps thin-skins evolve even more than pain which accurately reflects fitness consequences. We draw contrast with the Hawk-Dove model and identify several ways in which rationality hinders the evolution of the relatively vulnerable and peaceful type of agent.

We study the evolution of strategic psychological capabilities in a population of interacting agents. Specifically, we consider agents which are either blind or with mindsight, and either transparent or opaque. An agent with mindsight can observe the psychological makeup of a transparent agent, i.e., its logic, emotions, commitments and other elements that determine how it chooses actions. A blind agent cannot observe and opaque agents cannot be observed. Our assumption that mindsight and transparency are costly and optional exposes a middle ground between standard game theory without mindsight and evolution of preferences theory with obligatory and costless mindsight. We show that the only evolutionarily stable monomorphic population is one in which all agents are blind, opaque, and act-rational. We find that mindsight, transparency, and rule-rational commitments may evolve, albeit only in a portion of the population that fluctuates in size over generations. We reexamine the Ultimatum and Trust games in light of our findings and demonstrate that an evolved population of agents can differ significantly from a population of simplistic payoff-maximizers in terms of psychological traits and economic outcomes.

The paper applies multi-prize contest theory to explore the connection between scarcity of prizes and intensity of competition. Equilibrium levels of effort are compared across contests that differ in the number of prizes and in which the utility of winning or losing is influenced by the relative numbers of winners and losers. Application to the study of socioeconomic competition is discussed.