Project Summary The human tendency to discriminate emerges early in development: By 3 months of age, infants prefer looking at same-race faces over different-race faces. However, it is unclear how these perceptual tendencies translate to later racial prejudice and stereotypes. Previous infancy research on racial groups has mostly focused on perceptual skills (such as classifying faces of different races) rather than infants’ cognitive reasoning about and naturalistic behaviors toward different racial groups that may be more direct precursors of racial biases. Of the few studies that explore whether infants use race to guide their behaviors, there are conflicting evidences: Some find that infants show more positive behaviors toward same-race than different-race people, whereas others find no evidence of race influencing infants’ behaviors. Such discrepancy could be due to these studies not accounting for infants’ experience with different race individuals. Exposure to different races clearly impacts infants’ face processing; it is possible early social experience with racially diverse individuals may also shape infants’ cognitive inferences about and social behaviors toward people who differ from them in race. The current project will thus fill a critical gap in our knowledge about how exposure to different races shape infants’ inferences about and stranger fear toward different-race individuals in the K99 phase (Aims 1 to 2). Aim 1 will examine whether infants have differential expectations about intra- vs. inter-racial interactions and whether racial diversity in their social networks and neighborhood environments relate to their expectations about interracial interactions. Aim 2 will utilize large-scale, longitudinal datasets to analyze whether infants show greater fear to racial outgroup than ingroup strangers, whether stranger fear is modulated by neighborhood racial demographics, and how this fear may change across development from infancy to childhood. In the independent R00 phase (Aims 3 to 4), the candidate will integrate techniques learned from her F32 and K99 phases to examine which type of exposure to different-race individuals most effectively changes race-based reasoning and behavior in infancy and childhood. Specifically, the R00 research will examine if interactive interactions with different-race individuals are more effective than passive exposure in changing inferences, stranger fear, and neural activities toward racial outgroup individuals in infants (Aim 3) and children (Aim 4). These studies will help elucidate the developmental trajectory of racial biases. This award will provide the candidate, who has a strong background in experimental research with children, with training in infancy and longitudinal research techniques to facilitate her transition to an independent researcher that can lead large-scale, longitudinal research efforts.