Fifteen-month-olds accept arbitrary shapes as symbols of familiar kind tokens

Across three experiments, we show that 15-month-old infants understand that arbitrary objects can be used as symbols. Experiment 1 shows that infants map geometric shapes (e.g., a triangle) onto familiar discourse referents (e.g., a duck) based on labeling (e.g., “Look, a duck!”). Experiment 2 shows that infants do not generalize these mappings to a new speaker. This rules out the alternative hypothesis that infants interpret the labeling events literally. Experiment 3 shows that infants are sensitive to the conceptual identity of the discourse referent. After being told that one shape represents an agent (e.g., a duck) and another shape represents a patient (e.g., a cup), infants attend differentially when the agent symbol moves towards the patient symbol than the opposite. This rules out the alternative hypothesis that infants interpret the labeling events as referential pacts. The findings jointly indicate that symbolic relations are easily activated and available early in human development.