Categorization of dynamic realistic motion events: Infants form categories of path before manner

• Infants at 14 months categorize a figure’s path and manner in realistic motion events.
• Categorization of path occurred in the presence of a ground object and manner in the absence of one.
• Infants categorizing path showed a stronger novelty preference than those categorizing manner.

Acquiring verbs and prepositions requires categorization of spatial relations. This study examined whether a ground object differentially influences 13- to 15-month-old English-learning infants’ categorization of a figure’s path (e.g., around; Experiment 1) and manner (e.g., hopping; Experiment 2) of motion in non-linguistic dynamic realistic events. Furthermore, we tested whether categorizing path is “easier” than categorizing manner. Results revealed that infants categorized path only in the presence of a ground object, validating Talmy’s definition of path. In contrast, infants categorized manner only in the absence of a ground object. Finally, infants categorizing path showed stronger novelty preferences than those categorizing manner, supporting a primacy of path. Infants showed sensitivity to event components lexicalized in relational terms.