Variability in toddlers' ability to verbally update their mental representations of absent objects.

Early in development children rely on other people's verbal testimony to acquire information about things that are not available to their immediate perception. There is evidence that children as young as 22 months can use language to learn about an object that undergoes a property change (e.g., "Lucy got wet") out of their sight. If the verbal input conveys a change in the location of an absent object (e.g., "The puppy is moved from the bag to the box"), 30-month-olds successfully use this information and find the object in its new location, whereas the majority of 23-month-olds perseverate to the object's initial location. These findings suggest that young children's ability to use verbal testimony to update their mental representations of absent entities shows variability within and across tasks. The goal of the current research was to replicate the pattern of performance observed in previous cross-sectional studies within the same group of children. A total of 59 2-year-olds (M = 26.9 months, range = 21.4-34.5) were administered two versions of verbal updating tasks: property and location change. As a group, children showed more variable performance when they learned about a change in an object's location (58% success) than when they learned about a change in its property (75% success). Moreover, comparison of individual children's performance across the two tasks revealed that at this age children found the location change harder to update than the property change. We discuss possible explanations for children's differential performance on verbal updating tasks involving property and location change.