Infants' symbolic comprehension of actions modeled with toy replicas.

While very young children's understanding of objects as symbols for other entities has been the focus of much investigation, very little is known concerning the emergence of comprehension for symbolic relations among actions modeled with toy replicas and their real counterparts. We used videotaped depictions of real actions in a preferential looking task to assess toddlers' ability to comprehend such connections for action categories aligned with familiar object concepts. Across two experiments, 16- and 18-month-olds provided no evidence of understanding such relations, even when action categories were highlighted with verbal prompts. Among 24- and 26-month-olds, comprehension of relations between certain actions modeled with toys and videos of their real-world counterparts began to emerge, independent of expressive vocabulary size. Implications of our results for theoretical conclusions drawn from use of the generalized imitation procedure to study early conceptual development are discussed.