Children's level of participation in a false-belief task, age, and theory of mind.

The hide-and-seek deception task of M. Chandler, A. S. Fritz, and S. Hala (1989) was modified to provide a more precise estimate of the age at which children acquire and manifest a theory of mind. Two characters (good, bad) and two levels of involvement (pretend play, sociodramatic play) were incorporated into the research design, so that children's representational understanding of deception could be studied. Two-, 3-, and 4-year-olds (N = 90) participated in the study. The results indicated that 4-year-olds used significantly more deceptive strategies than 2- and 3-year-olds in pretend play and in sociodramatic play. There was no difference between 2- and 3-year-olds in the use of deceptive strategies; they used significantly fewer strategies in the bad roles than in the good roles. No significant differences were found in the 3 age groups' performances in the good-character tasks. The reality-masking hypothesis (P. Mitchell, 1994) accounts for the differences in performances on that task; thus, children younger than 4 years old do seem to have a theory of mind.