Abstract
The purpose of this research was to investigate the development of junior high school and senior high school students' Self-Efficacy (SE) for Social Interaction with Infants and the relation between that and their SE for Interaction with Peers. Two scales, SE for Social Interaction Scale with Infants and SE for Interaction with Peers were developed and administered to 659 junior high school students-333 boys and 326 girls, 774 senior high school students-383 boys and 391 girls. By factor analysis, it was found that SE for Social Interaction Scale with Infants had one-factor structure, while SE for Interaction with Peers was divided into two subscales. By examining students' development processes of SE for Social Interaction with Infants from the point of view in age and sex, and the relation of SE for Interaction with Peers, the results were as follows : 1) Boys' SE for Social Interaction with Infants was lower than girls'. 2) SE for Social Interaction with Infants was related to 'sympathetic factor' of their SE for Social Interaction with Peers.
