Infants understand the referential nature of human gaze but not robot gaze.

Infants can acquire much information by following the gaze direction of others. This type of social learning is underpinned by the ability to understand the relationship between gaze direction and a referent object (i.e., the referential nature of gaze). However, it is unknown whether human gaze is a privileged cue for information that infants use. Comparing human gaze with nonhuman (robot) gaze, we investigated whether infants' understanding of the referential nature of looking is restricted to human gaze. In the current study, we developed a novel task that measured by eye-tracking infants' anticipation of an object from observing an agent's gaze shift. Results revealed that although 10- and 12-month-olds followed the gaze direction of both a human and a robot, only 12-month-olds predicted the appearance of objects from referential gaze information when the agent was the human. Such a prediction for objects reflects an understanding of referential gaze. Our study demonstrates that by 12 months of age, infants hold referential expectations specifically from the gaze shift of humans. These specific expectations from human gaze may enable infants to acquire various information that others convey in social learning and social interaction.