Altruistic punishment in action: movement vigour in neuroeconomic choice

Abstract Decision and action unfold in parallel, with movement vigour typically reflecting subjective value: the higher the subjective value assigned to an option, the greater the vigour in moving towards it. Here, we reveal a striking inversion of this classic vigour–value relationship in the context of altruistic punishment. In study 1, using a motor version of the Ultimatum Game, we found that vigour increased with offer amount when offers were accepted but decreased when offers were rejected (altruistic punishments). In study 2, we disentangled the factors driving this reversal using a social exchange task. We found that vigour during punishment was not determined by self-cost or other cost alone, but by the efficiency of punishment—the ratio of other cost to self-cost. These findings establish movement vigour as a dynamic read-out of social utility and demonstrate that social preferences can fundamentally reshape vigour–value mappings.