Abstract
The present study investigated whether one-year-olds are capable of active teaching, which is believed to be a type of social intelligence. It also clarified the relation between active teaching and the acquisition of one year-olds' mirror self-recognition. Forty-three toddlers (ages 12-23 months) participated in an experiment where they saw an experimenter who was unable to solve a problem, and they also took the Mark Test developed by Gallup (1970). In the first task the experimenter failed to succeed on a task using material from the Kyoto Scale of Psychological Development, in which one forced a round plate into a square hole. Observations of toddlers' reactions showed active teaching by about 60 % of the participants who were older than 20 months. In additions, participants' ability to teach was correlated with their acquisition of mirror self-recognition. The results were discussed in terms of self-other differentiation based on representational abilities acquired at about 18 months of age.
