Abstract
Based on interviews with teachers, department chairs, principals and staff developers, observations of hundreds of lessons, and a perusal of the social studies and broader, school change literature, dominant barriers to the promotion of thinking were identified. Six barriers emerged: instruction as knowledge transmission, a curriculum of coverage, teachers' low expectations of students, large numbers of students, lack of planning time, and a culture of teacher isolation. The way in which each barrier negatively impacts the promotion of students' higher order thinking is explained, combining analytic arguments with quantitative and qualitative research findings.