Multigame Contact: A Double-Edged Sword for Cooperation
实验研究多游戏接触对合作的影响，发现它不提高总体合作率，但使双方在多个游戏中同时合作或同时背叛更可能，如同双刃剑。
We study experimentally the effect of multigame contact on cooperation, with each subject playing a pair of indefinitely repeated prisoner’s dilemmas. Multigame contact is present if a subject plays both games with a single partner, and it is absent if each of the two games is played with a different partner. In contrast to the theoretical prediction, multigame contact does not increase overall cooperation rates. Nonetheless, multigame contact systematically affects behavior and outcomes, acting like a double-edged sword, in the sense that subjects link decisions across games and, consequently, mutual cooperation and mutual defection in both games become more likely.