Ethnic discrimination unlearned: experience in the repeated Trust Game reduces trust bias

INTRODUCTION: Discrimination toward ethnic minorities is a persistent societal problem. One reason behind this is a bias in trust: people tend to trust their ingroup and comparatively distrust outgroups. METHODS: In this study, we investigated whether and how people change their explicit trust bias with respect to ethnicity based on behavioral interactions with in- and outgroup members in a modified Trust Game. RESULTS: Subjects’ initial explicit trust bias disappeared after the game. The change was largest for ingroup members who behaved unfairly, and the reduction of trust bias generalized to a small sample of new in- and outgroup members. Reinforcement learning models showed subjects’ learning was best explained by a model with only one learning rate, indicating that subjects learned from trial outcomes and partner types equally during investment. DISCUSSION: We conclude that subjects can reduce bias through simple learning, in particular by learning that ingroup members can behave unfairly.