Fourteen-month-olds know what "we" have shared in a special way

People often express excitement to each other when encountering an object that they have shared together previously in some special way. This study investigated whether 14-month-old infants know precisely what they have and have not shared in a special way (and with whom). In the experimental condition an adult and infant shared an object (the target) excitedly because it unexpectedly reappeared in several places. They then shared 2 other objects (the distractors) in a more normal fashion. Later, the adult reacted excitedly to a tray containing all 3 objects and then made an ambiguous request for the infant to hand "it" to her. There were 2 control conditions. In 1 of them, a different adult, who knew none of the 3 objects, made the ambiguous request. In the other control condition, the adult who made the request had previously experienced the objects only alone, while the infant looked on unengaged. Infants in the experimental condition chose the target object more often than the distractors and more often than they chose it in either control condition. These results demonstrate that 14-month-old infants can identify which one of a set of objects "we" - and not just I or you alone - have had a special experience with in the past.