Social group discovery, structure, and stereotype updating.

Group stereotypes are difficult to change and drive discriminatory behavior across numerous consequential contexts. Across seven experiments, we test predictions made by a domain-general structure learning model to understand how people decide what "counts" as a group and how those group representations inform our beliefs-here, stereotypes about what a group believes-about constituent members. We have two central hypotheses. First, given low levels of deviance within a collective, participants will perceive a single group among all agents; however, as deviance of one "counter-stereotypical" agent increases, that agent will be subtyped out of the group, yielding two perceived clusters. Second, as deviance increases, confidence in one's beliefs about the group and, correspondingly, a novel group member should decrease; however, once the deviating agent is subtyped out, confidence in one's beliefs about the remaining agents and novel member should increase again. We found consistent evidence for the first prediction: As one agent's deviation from the group increased from 0% to 25%, the deviant was subgrouped. As deviation increased to 50% and more, the deviant was subtyped out of the group. We only observed support for the second prediction in two of the experiments using the confidence measure. However, an exploratory analysis of these experiments revealed a new way to index group stereotype precision-quantifying perceived similarity of all the nondeviating agents to one another. Using this measure of group-based beliefs, we see support for our second hypothesis in a majority of the experiments. (PsycInfo Database Record (c) 2025 APA, all rights reserved).