The ontogenetic roots of understanding others: How action anticipation develops in infancy.

Anticipating others' goal-directed actions is a core component of social cognition, yet its developmental trajectory and underlying mechanisms remain debated. In this longitudinal eye-tracking study, 107 infants were assessed at 6, 10, and 14 months. Spontaneous (first-trial) and experience-based (trial-by-trial) action anticipation were distinguished during repeated goal-directed grasping actions, and associations with motor development and maternal sensitivity were examined. Spontaneous anticipation increased with age, with highest response rates at 14 months, whereas experience-based changes in anticipation were evident in 10-month-olds. Individual differences in motor abilities-particularly fine motor skills and action-perception integration-were linked to changes across trials (experience-based anticipation), whereas maternal sensitivity was not significantly associated with spontaneous or experience-based anticipation. The findings provide novel longitudinal evidence that individual variability in motor competence and action-perception integration relates to the development of action anticipation in infancy. (PsycInfo Database Record (c) 2026 APA, all rights reserved).