Research shows relations between entity theories-i.e., beliefs that traits and abilities are unchangeable-and youth psychopathology. A common interpretation has been that entity theories lead to psychopathology, but another possibility is that psychopathology predicts entity theories. The two models carry different implications for developmental psychopathology and intervention design. We tested each model’s plausibility, examining longitudinal associations between entity theories of thoughts, feelings, and behavior and psychopathology in early adolescents across one school year (N = 59, 52 % female, ages 11-14, 0 % attrition). Baseline entity theories did not predict increases in psychopathology; instead, baseline psychopathology predicted increased entity theories over time. When symptom clusters were assessed individually, greater youth internalizing (but not externalizing) problems predicted subsequent increases in entity theories. Findings suggest that the commonly proposed predictive model may not be the only one warranting attention. They suggest that youth psychopathology may contribute to the development of certain kinds of entity theories.