Evidence of group bias based on race, ethnicity, nationality, and language emerges early in the life span. Although understanding the initial acquisition of group bias has critical theoretical and practical implications, precisely how group biases are acquired has been understudied. In two preregistered experiments, we tested the hypothesis that generalized social group biases can be acquired through exposure to positive nonverbal signals directed toward a novel adult from one group and more negative nonverbal signals directed toward a novel adult from another group. We sought to determine whether children would acquire global nonverbal signal-consistent social group biases that extended beyond their explicit social preferences, by measuring children's preferences, imitation, and behavioral intentions. Supporting our preregistered hypotheses, preschool-age participants favored small and large groups whose member received positive nonverbal signals, relative to groups whose member received more negative nonverbal signals. We also replicated prior work indicating that children will acquire individual target biases from the observation of biased nonverbal signals. Here we make the case that generalized social group biases can be rapidly and unintentionally transmitted on the basis of observational learning from nonverbal signals. (PsycInfo Database Record (c) 2020 APA, all rights reserved).