Children's intrinsic motivation for school work has been recognized as an important contributor and predictor of school achievement. It is characterized by enjoyment and valuing of learning for the inherent pleasure its accomplishment brings. Important features include curiosity, persistence, autonomy, a mastery orientation, and a preference for challenging tasks. Most intrinsic motivation research has focused on college students, adolescents, and children in middle childhood. This study targeted school beginners. Young children vary in the extent to which they are intrinsically motivated toward academic work, but the development of this motivation is not fully understood. The study's participants were 48 boys and 35 girls from 8 first-year classes in 5 Auckland (New Zealand) elementary schools. Measures included: (1) academic competence; (2) social competence; (3) perceived social competence; (4) perceived academic competence; (5) academic intrinsic motivation; and (6) teacher questionnaire. The study showed children's perceptions of their social competence as the largest contributor to their intrinsic motivation for school work. Children's social behavior, as perceived by their teachers, was also strongly related to academic performance. Contains 31 references. (BGC)