Hot–cold reciprocation gaps

We study whether and why the mode of decision-making affects reciprocation in a binary trust game, using three preregistered online experiments. Trustees – some of whom were exogenously induced to be surprised by trust – either decided whether to reciprocate after observing their partner’s choice ( hot mode) or committed in advance to a contingent response plan ( cold mode). In our Baseline experiment, once participants gained experience, reciprocation became more likely under hot than under cold decision-making, especially when trust was unlikely – consistent with a model in which positive surprise at being trusted increases the utility of reciprocating. Results from the other two experiments show that surprise promotes reciprocation only when trust reflects an intentional choice by the trustor and when cognitive load in the decision environment is not too high.