Young children expect pretend object identities to be known only by their partners in joint pretence.

The present study examined whether three-year-old children (age = 42-48 months, n = 57; 31 boys) understand that object identities stipulated during pretend play could only be known by people witnessing the stipulation. Children participated in pretend scenarios that included some objects and two experimenters. Two pretend episodes corresponded to an object: one connected to its conventional function, the other to a pretend identity made-up on the spot. These episodes happened either in the presence or absence of the other person. In the test phase, this experimenter expressed an intention to do something with an object and asked for a 'missing' prop. The prediction was that in case she was present previously, children would be more likely to select the prop corresponding to a pretence stipulation, compared to when she was absent. The results confirmed this pattern: in the absent condition, 68.42% of the participants chose the prop connected to the conventional use of the object, while 31.58% chose the prop corresponding to its identity stipulated in pretend play. It seems that preschool aged children refrain from generalizing their knowledge about the pretend identity of an object, in case their interactive partner could not know of this identity.