Direct and Observed Joint Attention Modulate 9-Month-Old Infants' Object Encoding.

Sharing joint visual attention to an object with another person biases infants to encode qualitatively different object properties compared to a parallel attention situation lacking interpersonal sharedness. This study investigated whether merely observing joint attention amongst others shows the same effect. In Experiment 1 (first-party replication experiment), N = 36 9-month-old German infants were presented with a violation-of-expectation task during which they saw an adult looking either in the direction of the infant (eye contact) or to the side (no eye contact) before and after looking at an object. Following an occlusion phase, infants saw one of three different outcomes: the same object reappeared at the same screen position (no change), the same object reappeared at a novel position (location change), or a novel object appeared at the same position (identity change). We found that infants looked longer at identity change outcomes (vs. no changes) in the "eye contact" condition compared to the "no eye contact" condition. In contrast, infants' response to location changes was not influenced by the presence of eye contact. In Experiment 2, we found the same result pattern in a matched third-party design, in which another sample of N = 36 9-month-old German infants saw two adults establishing eye contact (or no eye contact) before alternating their gaze between an object and their partner without ever looking at the infant. These findings indicate that infants learn similarly from interacting with others and observing others interact, suggesting that infant cultural learning extends beyond infant-directed interactions.