When seeing follows believing: The role of social likelihood in demographic estimation

This study investigates how individuals estimate the size of demographic groups and whether these estimations are guided by contextual expectations rooted in social associations. Across three experiments (N = 180), we explore the hypothesis that people employ a rational compensation strategy when estimating group prevalence, adjusting their judgments toward likely values depending on contextual cues. In Experiment 1, participants estimated the proportions of gender and political affiliation from crowds of South Korean politicians. The results replicated the overestimation of minorities and underestimation of majorities but also demonstrated that estimation errors were modulated by contextual alignment-that is, participants' estimates were more refined when group characteristics aligned with stereotypical associations (e.g., women with progressive politics). Experiment 2 extended these findings by examining categorical judgments of majority status, wherein participants demonstrated greater sensitivity to proportion when gender and political affiliation conformed to expected associations. Experiment 3 confirmed that such likelihood-based refinements stem from semantic associations: participants estimated differing gender ratios in hypothetical political groupings depending on which party was described as being the majority. In Experiments 1 and 2, individual differences in gender-party stereotype endorsement did not significantly correlate with estimation errors. Together, the findings illustrate that group size estimation is not purely perceptual but rather influenced by a context-sensitive rational strategy that incorporates associative knowledge. Thus, this work provides a nuanced account of demographic misperception and offers implications for understanding how people form impressions of diversity in political and social contexts.