Inequity-aversion and relative kindness intention jointly determine the expenditure of effort in project teams.

The literature on team cooperation has neglected the effects of relative kindness intention on cooperation, which we measure by comparing the kindness intentions of an agent to her group members to the kindness shown by other members to this same agent. We argue that the agent's emotional reaction to material payoff inequity is not constant, but rather affected by her relative kindness intention. Then, we apply the model to team projects with multiple partners and investigate how inequity-aversion and relative kindness intention jointly influence team cooperation.

Is Tit-for-Tat the Answer? On the Conclusions Drawn from Axelrod's Tournaments.

Axelrod's celebrated Prisoner's Dilemma computer tournaments, published in the early 1980s, were designed to find effective ways of acting in everyday interactions with the strategic properties of the iterated Prisoner's Dilemma game. The winner of both tournaments was tit-for-tat, a program that cooperates on the first round and then, on every subsequent round, copies the co-player's choice from the previous round. This has been interpreted as evidence that tit-for-tat is an effective general-purpose strategy.

Strategic behavior in monkeys.

In a recent paper, Lee et al. examined adaptive decision-making processes by training monkeys to play a competitive game against a computer programmed to play using various strategies. They found that the monkeys' responses were sensitive to the computer's strategies and consistent with reinforcement learning.

Effects of financial incentives on the breakdown of mutual trust.

Disagreements between psychologists and economists about the need for and size of financial incentives continue to be hotly discussed. We examine the effects of financial incentives in a class of interactive decision-making situations, called centipede games, in which mutual trust is essential for cooperation. Invoking backward induction, the Nash equilibrium solution for these games is counterintuitive.

Bonus and Penalty in Common Pool Resource Dilemmas under Uncertainty.

Common pool resource (CPR) dilemmas constitute a class of social dilemmas in which equilibrium behavior results in Pareto deficient outcomes that are not at all desirable by the group. We focus on a class of CPR dilemmas that, in addition to strategic uncertainty about the harvesting behavior of the other group members, include environmental uncertainty about the size of the CPR. In an attempt to decrease the rate of requests from the common pool, and thereby increase individual payoffs, we extend previous research-both theoretically and experimentally-in two different directions.