The relationships between adolescents' reading comprehension and their metacognitive knowledge and self-system beliefs were studied in three groups of subjects: French nationals, Caucasian Americans, and African Americans. Subjects were tested on measures of reading comprehension, metacognitive knowledge about reading processes, attributional beliefs, and academic self-concept. Correlation and regression analyses indicated cultural differences in the predictors of reading comprehension among the three groups. For French and Caucasian Americans, reading comprehension scores were related to metacognitive knowledge, academic self-concept, and attributions of success to ability. However, metacognition and motivational beliefs were mostly unrelated to comprehension performance for African Americans. Results are discussed in terms of verification of a model of motivational influences on performance, of cultural and ethnic group differences in beliefs, and the implications for generalizability of research results.A growing body of research has addressed motivational influences on individuals' performances in cognitive domains. A starting point for this research is the assumption that cognitive competence is not sufficient for excellent performance; rather, children must be motivated to use their competencies and, relatedly, must have the belief systems that promote effortful performance in order to succeed on challenging We wish to thank Kenneth Levine for assistance with data collection and coding. Portions of this work were completed while Beth Kurtz-Costes was an 352 B. Kurtz-Costes et al.cognitive tasks. The present research was aimed at better understanding the relationship between young adolescents' belief systems and their reading comprehension performance, and at examining potential ethnic differences in this relationship. This research was guided by a model linking children's metacognitive knowledge and regulation to their motivational beliefs about their abilities and about the factors underlying successful performance (Borkowski, Carr, Rellinger, and Pressley, 1990; Schneider, 1987, 1990). According to this model, children who possess accurate knowledge about cognitive processes (i.e. metacognitive knowledge) recognize that effortful performance is necessary for consistent success. Further, children who believe both that they are capable of success (i.e. positive academic self-concept) and that successful outcomes are the result of their own ability and effort expenditure will be more likely to succeed than peers who have maladaptive beliefs Omelich, 1979, 1985). Adaptive beliefs-including a belief in one's own ability as well as the importance of effort in determining task outcomes-serve a motivational role on challenging tasks. Thus children who have adaptive beliefs will be more likely to try hard. Effortful performance, especially in conjunction with appropriate strategy use, will enhance the probability of success .A number of studies have provided evidence supporting this model (Carr and Borkowski, 198...