First-Glance Biases Apply to Groups Too: Group Racial Diversity Shapes Individuals' Decision-Making via Automatic Visual Processes

The visual perception of individuals has received considerable attention (visual person perception), but little social psychological work has examined the processes underlying the visual perception of groups of people (visual people perception). Ensemble-coding is a visual mechanism that automatically extracts summary statistics (e.g., average size) of sets of stimuli (e.g., geometric figures). Across four studies, we demonstrate that ensemble-coding further underlies the perception of high-level properties (e.g., diversity) that are unique to social groups, as opposed to individual persons. Moreover, we find that visually extracted diversity information influences observers' social behavior - specifically, which team they choose to join (Studies 1 and 2) and which teams they choose to trust (Studies 3a and 3b). Observers not only perceived group variance, but then used these perceptions in social decision-making. All together, we show that humans can rapidly and accurately perceive not only individual persons, but also emergent social information unique to groups of people. These people perception findings demonstrate the importance of visual processes for enabling people to perceive social groups and behave effectively in group-based social interactions. Finally, moving beyond work on first-impression biases (i.e., racial prejudice) regarding individual persons, we discuss implications for first-impression biases regarding entire groups or teams of people.