Gulliver, Goliath and Goldilocks

Early development of body self-awareness was examined in 57 children at 18, 22, or 26 months of age, using tasks designed to require objective representation of one's own body. All children made at least one body representation error, with approximately 2.5 errors per task on average. Errors declined with age. Children's performance on comparison tasks that required them to reason about the relative size of objects and about objects as obstacles, without considering their own bodies, was unrelated to performance on the body awareness tasks. Thus, the ability to represent and reflect on one's own body explicitly and objectively may be a unique dimension of early development, a distinct component of objective self-awareness that emerges in this age period.

Executive function is recognized as a critical component of children's cognitive and social development. In two studies, a measure of executive function that had been used in research with chimpanzees was adapted for preschoolers. On this task, called Less Is More, children must point to a smaller reward (two candies) to receive a larger reward (five candies). In Study 1 (N= 101), performance was significantly related to age (3 vs. 4), verbal ability, and established measures of executive function. In Study 2 (N= 128), symbolic representations substituted for real candies in this task. Three-year-olds' performance improved significantly as a function of symbolic distancing. This research has implications for the role of symbol systems in the development of executive control over thought and action.

We report a perception-action dissociation in the behavior of normally developing young children. In adults and older children, the perception of an object and the organization of actions on it are seamlessly integrated. However, as documented here, 18- to 30-month-old children sometimes fail to use information about object size and make serious attempts to perform impossible actions on miniature objects. They try, for example, to sit in a dollhouse chair or to get into a small toy car. We interpret scale errors as reflecting problems with inhibitory control and with the integration of visual information for perception and action.