Teachers' beliefs about high-critical thinking and low-critical thinking (CT) activities have been the focus of a growing body of literature in teacher education, based on theory and research indicating that beliefs influence how teachers interact with learners and organize classroom tasks. The subset of this work that focuses on teachers' CT-related beliefs has investigated the relationship between such beliefs and teachers' perceptions of learners' advantage level--i.e., learners' academic track, achievement level, or SES advantages. Studies investigating differences in CT-related beliefs for high-advantage and low-advantage learners have been motivated by the assertion that teachers judge high-CT activities to be ineffective for low-advantage learners, whom are purportedly seen as ill prepared to handle high-CT activities and in need of a remedial regimen of low-CT ones. According to this line of reasoning, a self-fulfilling prophecy may result in which low-advantage learners receive few high-CT activities, which restricts their academic growth, which in turn makes high-CT activities less likely to be used; in contrast, high-advantage learners receive abundant high-CT activities, which enhance their academic growth, which makes still more high-CT instruction likely. In this article, the author features his latest comparison study of how teachers view the practice of using CT pedagogies across student achievement levels. This study is a significant contribution to a growing body of research associated with teachers' beliefs about the use of critical thinking strategies. (Contains 2 tables and 1 figure.)