Using a high-stakes field experiment conducted with a financial brokerage, we implement a novel design to separately … asset, his peers may also want to purchase it, both because they learn from his choice ("social learning") and because his …

news. This tendency is assumed to support the optimism bias. Whether this learning bias is specific to ‘high …-level' abstract belief update or a particular expression of a more general ‘low-level' reinforcement learning process is unknown. Here … we report evidence in favour of the second hypothesis. In a simple instrumental learning task, participants incorporated …