By 1942, when the NEA's National Council for the Social Studies published its Thirteenth Yearbook, [Washington, DC: The National Council for the Social Studies, a Department of the National Education Association, 1942] this method was deemed to be too narrow, since it did not make students any less susceptible to propaganda. (Howard R. Anderson, 'Introduction' in Ibid., p. vi; Hilda Taba, 'The Evaluation of Critical Thinking', in Ibid., pp. 161-2) Also, according to Hilda Taba, (Ibid., p. 162) the focus on resistance to propaganda was merely negative, since it aimed only to help students to diminish the influence of harmful, external content, and did little to promote a wider use of critical thinking in guiding one's own, constructive reasoning.
Anderson and Taba both cite a study by Wayland Osborn, who concluded that:
While the possession of knowledge and intelligence is no doubt necessary in order to do critical thinking, the results of this experiment strongly suggest that an individual may, according to commonly obtained measures, possess both these traits to a high degree and yet be highly susceptible to propaganda influences. ('An Experiment in Teaching Resistance to Propaganda' The Journal of Experimental Education 8 [1939]: 16)