Addressing two issues of Dweck and Leggett's (1988) social cognitive theory of personality, this short-term longitudinal field study investigated the relationship between implicit theories about the self and school anxiety among adolescents making the transition to junior high school. It was hypothesized that students who believed that their attributes were fixed aspects of the self would experience more anxiety than others, particularly if the former reported low confidence in the attribute. Participating were 110 seventh graders who responded to assessments of theory of intelligence, confidence in intelligence, and school anxiety. Findings indicated a main effect for theory of intelligence, showing that, compared to 'incremental theorists', 'entity theorists' had higher anxiety levels. A main effect for confidence in intelligence showed that students with low confidence had higher anxiety than others. As predicted, the interaction of these two variables was significant, indicating that entity theorists with low confidence had higher anxiety than other students. Analogous measures in the domain of personality yielded similar results. No main effects were found for sex of subject. The effect of grades on anxiety was not significant. It is concluded that results support Dweck and Leggett and provide insight into the 'storm and stress' hypothesis, indicating that for some students the changes in adolescence are threatening, while others may find them an opportunity for growth and development. Figures and assessment instruments are attached. (RH)