Encouraging Cooperation: Revisiting Solidarity and Commitment Effects in Prisoner's Dilemma Games¹

Pre‐play discussion consistently increases cooperation in dilemma interactions. Most explanations of this “cheap‐talk” effect are based on either commitment or group solidarity effects. Because discussion about the upcoming dilemma allows participants to make promises and creates group solidarity, the 2 explanations are often confounded. This paper aims to clarify past results by having participants engage in an unrelated discussion prior to a...