Should I learn from you? Seeing expectancy violations about action efficiency hinders social learning in infancy

Infants generate basic expectations about their physical and social environment. This early knowledge allows them to identify opportunities for learning, preferring to explore and learn about objects that violate their prior expectations. However, less is known about how expectancy violations about people's actions influence infants' subsequent learning from others and about others. Here, we presented 18-month-old infants with an agent who acted either efficiently (expected action) or inefficiently (unexpected action) and then labeled an object. We hypothesized that infants would prefer to learn from the agent (label-object association) if she previously acted efficiently, but they would prefer to learn about the agent (voice-speaker association) if she previously acted inefficiently. As expected, infants who previously saw the agent acting efficiently showed greater attention to the demonstrated object and learned the new label-object association, but infants presented with the inefficient agent did not. However, there was no evidence that infants learned the voice-speaker association in any of the conditions. In summary, expectancy violations about people's actions may signal a situation to avoid learning from them. We discussed the results in relation to studies on surprise-induced learning, motionese, and selective social learning, and we proposed other experimental paradigms to investigate how expectancy violations influence infants' learning about others.