Uncalculating Cooperation Is Used to Signal Trustworthiness

Abstract

Humans frequently cooperate without carefully weighing the costs and benefits. As a result, people may wind up cooperating when it is not worthwhile to do so. Why risk making costly mistakes? Here, we provide the first experimental demonstration that reputation concerns provide an answer: people cooperate in an uncalculating way in order to signal their trustworthiness to observers. We present two economic game experiments in which uncalculating versus calculating decision-making is operationalized by (i) a subject’s choice of whether to reveal the precise costs of cooperating (Experiment 1) and (ii) the time a subject spends considering these costs (Experiment 2). In both, we find that subjects are more likely to engage in uncalculating cooperation when their decision-making process is observable to others. Furthermore, we confirm that people who engage in uncalculating cooperation are perceived as, and actually are, more trustworthy than people who cooperate in a calculating way. Together, these data provide the first evidence that uncalculating cooperation is used to signal trustworthiness, and is not merely an efficient decision-making strategy that reduces cognitive costs. Our results thus help to explain a range of puzzling behaviors such as extreme altruism, the use of ethical principles, and romantic love.

Keywords: reputation, social evaluation, decision-making, experimental economics