Effects of a philosophy classroom dialogue intervention on students’ value-loaded critical thinking

In secondary school philosophy classes students learn to reason critically about social and scientific issues. This study examined the effects of a whole-class, teacher-led philosophy classroom dialogue intervention on students' value-loaded critical thinking. Value-loaded critical thinking is logically consistent, self-reflective reasoning focused on making moral value-judgments about what is right to believe or do. In a quasi-experimental study (N = 437 students) with a pre-test post-test design, we investigated whether engaging in classroom dialogues in which the teachers implemented five design principles for promoting value-loaded critical thinking and transfer thereof, positively affected students' (n = 150) value-loaded critical thinking in transfer tasks. The results were compared to two comparison conditions: students (n = 149) who participated in regular teacher-led philosophy classroom dialogues and students (n = 145) who followed a regular 10th-grade curriculum without philosophy classes. Results showed that students in the intervention condition outperformed students in both comparison conditions on referring to moral values. Regarding critical reasoning, we only found significant effects compared to the students who followed the regular 10th-grade curriculum. Findings indicate that a specifically designed dialogic intervention can enhance students' capacities in value-loaded critical thinking.