This was previously posted and is currently enjoying a traffic surge. I'm a skeptic of teaching critical thinking as a skill independent of any discipline.
James Hanley vents his frustration over the difficulty cultivating critical-thinking skills in his students:
A recent study found that 45% of college students don’t learn critical thinking skills during their time in college. I admit it. I don’t think I managed to teach any of these students how to think critically. It’s impossible to do so if they skip class regularly and don’t bother with the assigned readings. I’ve even shown students the percentage of “F”s I’ve given in the same class over the prior two years, and it has no effect on student performance. I’m going to spend the next couple of months doing a major revamp of some of my classes. Not just adjusting the syllabus, but radically restructuring how I’m teaching them. What I’m doing isn’t working. Maybe it never has as well as I thought, and I’m just now learning how to really recognize it.
As Professor Hanley suggests, part of the problem is with students who don't come to class or complete assigned readings, but in a paper on teaching critical thinking skills, Daniel Willingham argues that it's impossible to improve general, transferable, critical-thinking skills because of the way problem-solving is structured. Critical thinking can only be improved within specific domains of knowledge as knowledge deepens and familiarity with certain repeated methods of analysis are encountered.
While I believe Hanley was referring to frustration with students in all of his political science classes, I would imagine that students in his Government class fare the worst because all, or almost all, are encountering new methods of analysis for the first time. If Willingham is right, students in an introductory political science class would tend to focus on the surface structure rather than the deeper structure of problems.
For an opposing view on teaching critical thinking, Diane Halperin says that general critical-thinking skills can be taught by applying methods derived from an understanding of cognitive psychology. Specifically, people can be taught transferable retrieval cues for deeper structural aspects of problems. But an important point she also makes is that individual differences in disposition must be considered. There is an ethic to think critically and some have it more than others and that difference still needs to be addressed. This is similar to Dr. Hanley's comment on students who aren't motivated to attend classes, but Halperin more specifically locates a cognitive dispositional problem that would likely continue in many students, even if they attended classes and did the assigned reading. That's because it isn't just about motivation to take certain observable actions; it's also about inclination, or the lack of inclination, to switch cognitive gears.