15-Month-Olds' Understanding of Imitation in Social and Instrumental Contexts

From early in development, humans use imitation to express social engagement, to understand social affiliations, and to learn from others. Nevertheless, the social and instrumental goals that drive imitation in everyday and pedagogical contexts are highly intertwined. What cues might infants use to infer that a social goal is driving imitation? Here we use minimal and tightly controlled visual displays to evaluate 15-month-olds' attribution of social goals to imitation. In particular, we ask whether they see the very same simple, imitative actions shared between two agents as social or nonsocial when those actions occur in the absence or presence of intentional cues such as obstacles, object goals, and efficient, causally effective action. Our results suggest that infants' attributing social value to imitation only in the absence of such intentional cues may be a signature of humans' early understanding of imitation. We propose, moreover, that a systematic evaluation of a set of simple scenarios that probe candidate principles of early knowledge about social and instrumental actions and goals is possible and promises to inform our understanding of the foundational knowledge on which human social learning is built, as well as to aid the building of human-like artificial intelligence.