Social Diversity is Associated with Diversified Visual Attention in Infancy

Perceptual narrowing of speech in infancy is often characterized as a maturational process driven by domain-specific experience with language. However, relatively little is known about the role of domain-general attentional mechanisms in this process. In the present study, we examined whether variability in infants’ everyday social environments is associated with attentional disengagement and whether disengagement, in turn, relates to perceptual narrowing. Seventy-nine bilingual infants aged 9–11 months completed a visual attentional disengagement task and an auditory discrimination task assessing sensitivity to a non-native Hindi dental–retroflex phonemic contrast. Infants’ social diversity was quantified as the proportion of lifetime exposure to caregivers of other racial backgrounds. Results revealed that infants who disengaged attention more efficiently showed greater discrimination of the non-native phonemic contrast. Greater exposure to racially diverse social partners predicted more efficient attentional disengagement but was not directly associated with phoneme discrimination. Mediation analyses indicated that social diversity was indirectly related to non-native discrimination via attentional disengagement. Together, these findings support a developmental cascade in which variability in infants’ social environments is associated with adaptations in domain-general attention that, in turn, relate to perceptual sensitivity. The results highlight attentional disengagement as a potential mechanism linking environmental diversity and perceptual specialization and underscore the importance of considering infants’ everyday social ecologies in theories of early learning.