Can critical thinking be taught?

The answer is yes, but answering the question, How? is much more difficult.

But first, let's ask: Why would you want to learn critical thinking (CT)?

According to one source, critical thinking gives you at least 20 advantages, more than 15 skills and abilities, and is necessary for more than ten aspects of a desirable life.  At least, that's how many they listed off.  Here are some examples of the claims:

  • Critical thinkers are masters of efficiency.
  • A critical thinker remains calm and knows when he is right.
  • CT improves the way we express our ideas.
  • It keeps us from becoming narrow-minded.
  • It helps us consider others' perspectives and reach conclusions based on facts, not feelings.
  • It helps people think 'outside the box.'
  • It teaches us to withhold personal judgments and biases.
  • It's necessary to live a meaningful life.
  • It creates good citizens who are informed about proper governance and overcome biases and prejudice.
  • It creates people who are the voice of reason in times of panic.

If you didn't meet with growing skepticism as you read down that list, you are probably thinking, I want this!  Where do I sign up for a class?

You can take a critical thinking course.  But don't expect to major in CT.  Just how much improvement in critical thinking can you expect to gain through education?

Kevin Possin, Professor Emeritus at Winona State University, has taught critical thinking courses.  He's also written a lot on the subject.  In a paper on this topic, Possin refers to what he considers to have been "the best effort at a basic-skills CT program to date," one that was based on the ideas of CT pioneer Robert Ennis.Possin, Kevin, "Commentary on "Why Not Teach Critical Thinking" by B. Hamby" (2016). OSSA Conference Archive. 60.  Referencing studies on the results of critical thinking improvement in college students, Possin remarked,

While these gains matched the gains it takes the average U.S. college graduate four years to achieve, they are still tragically meager.

He concludes the paper by saying that, while he doesn't recommend abandoning hope in the attempts to teach CT skills, he does recommend "lowering our expectations."

How, then, do the experts recommend learning CT?

The "consensus" of the experts

As my last article points out, there is anything but a consensus among all the recognized experts in CT on what CT actually includes.  However, the closest thing to a single consensus of experts came in the form of the "Delphi Report," published in 1990 with Dr. Peter A. Facione as the primary author.  Altogether 46 scholars in the field appended their names to the document, including Ennis, Lipman, and Paul, all mentioned in the last article.  The landmark paper makes 15 recommendations to educators for the increased use of CT instruction in all levels of education.

While acknowledging, "The experts harbor no illusions about the ease of designing appropriate instructional programs or assessment tools," the experts recommended that "minimum CT proficiency expectations should be set" for each level of education.  Sadly, this hasn't happened.  Frank Breslin, retired high-school teacher, wrote in Huffington Post

Apart from a few teachers who do train their students in critical thinking, most teachers do not for one simple reason — there is no time. State education departments mandate that so much material has to be covered that critical thinking cannot be taught, nor can the courses themselves be critically presented. In order to cover the curriculum, courses must be taught quickly, superficially, and uncritically, the infallible way of boring students.

What about university education?

A frequently cited 2016 meta-analysis set out to answer the question, Does College Teach Critical Thinking?Huber, C. R., & Kuncel, N. R. (2016). Does College Teach Critical Thinking? A Meta-Analysis. Review of Educational Research, 86(2), 431–468.   

Noting that their findings align with those of earlier studies on the subject, they concluded, "We estimate an average gain of 0.55 SDs on the disposition toward critical thinking over 4 years of college.... It is worth noting that a 0.50 SD gain for the person who starts at the 50th percentile would lift him or her to the 69th percentile, no small improvement in our minds."

At last, here's some evidence that university education can provide a general improvement in critical thinking skills and dispositions.  But the study tends to raise more questions than answers.  For one, what is it about college education that promotes critical thinking?  It appears that no one knows for sure.  Does the increase happen mostly in the early stages of college? Do gains speed up in the later years?  No strong evidence was found either way.

What about trends over time?  The study tested the suggestion that college has become less effective at teaching critical thinking.  Their findings:

Holding other moderators constant, more recent studies provided significantly smaller effect sizes than older studies. Given an equal mix of cross-sectional and longitudinal studies, the predicted 4-year gain is 1.22 SDs for a study published in 1963 [...], whereas the predicted gain is only 0.33 for a study published in 2011.

Are universities gradually failing in their efforts to promote critical thinking?  Or are students entering school at a higher level of CT ability than they were in years past?  These, too, are questions that remain unanswered.  In the US, college attendance went from 7 million in 1970 to 21 million in 2010.  Is it possible that higher numbers of less-prepared students attending college have diluted the numbers?  Have students become less willing or able to learn critical thinking skills over time?  There are no easy answers to these questions.

The study authors could not rule out the possibility that "critical thinking increases naturally with age and that some of the observed changes occur independently of college education."  Finally, how about the question of retention?  Do students retain CT skills long after college or learn to apply them in other contexts? The authors acknowledge:

Our search did not reveal any studies that followed up with college graduates to determine their levels of critical thinking skill or disposition later in life. If critical thinking skills are not practiced as frequently after graduation, they may diminish over time.

Are critical thinking skills transferable or are they domain-specific?

This is another pressing question.  Everyone knows each field of study requires specialized knowledge.  On the other hand, many people think of critical thinking skills as being broadly useful.As an example, the LinkedIn article cited at the top of this article confidently asserts, "Critical Thinking is a domain-general thinking skill." However, there is an increasing number of people who recognize CT as largely domain-specific.

The 2016 meta-study cited above refers to participants in one experiment who showed larger gains in domain-specific, but not domain-general, CT. They cite two other studies where psychology students each showed significant gains on a measure of psychological critical thinking but no significant gains on a test of general CT ability (The Watson Glaser Critical Thinking Appraisal).  The authors conclude, "This finding suggests that changes in domain-specific critical thinking may be related to mastery of that domain."

Other studies in separate disciplines agree with these results. A study of knowledge encapsulationKnowledge encapsulation is a type of learning where, over time, experts tend to develop mental shortcuts that are more efficient than reasoning based on careful analysis.  An example is a physician who, as a med student, uses a set of symptoms to make a diagnosis, but as an intern might say, "This is sepsis." Thus: "The concept of sepsis is sufficient to explain all relevant signs and symptoms; it encapsulates, or stands for, the student's detailed pathophysiological explanation." Example and quote from Schmidt, H. G., & Rikers, R. M. J. P. (2007). How expertise develops in medicine: knowledge encapsulation and illness script formation. Medical Education, 0(0), 071116225013002-??? tested cardiologists and neurologists in diagnosing cardiac cases.  As predicted, the cardiologists achieved a higher diagnostic accuracy.Rikers, R. M. J. P., Schmidt, H. G., & Boshuizen, H. P. A. (2002). On the Constraints of Encapsulated Knowledge: Clinical Case Representations by Medical Experts and Subexperts. Cognition and Instruction, 20(1), 27–45.   This was despite the fact that the neurologists and cardiologists undoubtedly had similar levels of critical thinking skills.

Would you expect professional philosophers to have higher than average CT skills?  How well would they handle everyday judgments, such as being swayed by irrelevant features of problems like question order or wording?  According to a 2015 study, no better than average adults. The study found that "neither framing effects nor order effects appear to be reduced even by high levels of academic expertise."Schwitzgebel, E., & Cushman, F. (2015). Philosophers’ biased judgments persist despite training, expertise and reflection. Cognition, 141, 127–137. 

Are there any generalized critical thinking skills?

There is evidence that some CT skills do transfer across domains, but the literature on broadly applicable CT skills is sparse.  First, consider some skills Possin considers to be widely transferable:

  • Using experimental evidence to provide evidence for or against a hypothesis in one area of science allows one to use that evidence in other disciplines too, especially in other sciences.
  • No matter what the subject is, denying the consequent is a relevant and valid argument, and learning how to recognize it is a valuable skill.Possin, K. (2014). Critique of the Watson-Glaser Critical Thinking Appraisal Test: The More You Know, the Lower Your Score. Informal Logic, 34(4), 393. 
  • Understanding and using deductive argument forms correctly is a valuable CT skill.Possin, K. (2016)

Compare, compare

The following studies have been cited in academic works about the possibility of learning transferable CT skills.  As I pored over the abstrusely-written studies, I observed a commonality: they all have to do with using comparisons to help the students learn more productive thinking patterns.  Let's take a brief look at three of them.

One study set out to determine the best way to help students recognize patterns in one domain (piles of rocks) and generalize the category knowledge to a new domain.  Both groups were shown images and asked to determine whether or not they belonged in the same category (the categories were not spelled out).  Afterward, they were given feedback as to whether their guess was correct. Experiment participants were asked to type a description of the rocks, whereas control participants just tried to guess the similarities.  Later both groups were tested using a set of geometric shapes that looked very different from the rocks they were trained on.  Those who had done the comparisons scored much better on the task.  (As an example, some of the rock patterns contained a rock on top of another rock.  The experiment group was more likely to recognize geometric patterns where the same shape was repeated vertically because they recognized this type of repetition as a category feature.) The study authors considered this to be an instance of domain transferred learning.Kurtz, K. J., Boukrina, O., & Gentner, D. (2013). Comparison promotes learning and transfer of relational categories. Journal of Experimental Psychology: Learning, Memory, and Cognition, 39(4), 1303–1310. 

In another study, participants were given instruction about principles of negotiation.  (For example, two children want the same lemon but one actually only wants the fruit and the other only wants the peel.)  The participants are told the general principle, as well as two cases that both involved the principle.  Then both groups were asked questions about how the principle relates to each case. However, the experiment group was asked to compare the two cases to each other, while this was not mentioned to the control group. Each was then asked to participate in a face-to-face negotiation.  The group that did the comparison was much more likely to apply the principle in the new situation. The authors conclude:

Even when cases follow one after another, there is no guarantee that people will notice their commonalities. Introducing explicit comparison across multiple cases in professional training could lead to more effective learning and transfer.Loewenstein, J., Thompson, L., & Gentner, D. (1999). Analogical encoding facilitates knowledge transfer in negotiation. Psychonomic Bulletin & Review, 6(4), 586–597. 

The final example is slightly different in that there aren't two existing items being compared.  Instead, the experimental subjects were asked to try to synthesize what they knew or create something new, and then test the results and compare them with the original. The control group wasn't taught this method. Both groups analyzed and interpreted their results, but only the experimental group did the comparisons. As a result, those in the experiment group were better able to explain their reasoning than the control group.  They were also much more likely to offer creative ways to improve the experimental methods or to describe the limitations of the methods they used.  Tests a year later found they were continuing to use this method even though it had only been briefly taught.Holmes, N. G., Wieman, C. E., & Bonn, D. A. (2015). Teaching critical thinking. Proceedings of the National Academy of Sciences, 112(36), 11199–11204. 

Possin also cites a couple other studies that produced similar results.  It is evident that, while most critical thinking is apparently domain-specific, there are skills and thinking patterns that can be useful in a more general way. 

While I don't believe the evidence supports all the claims of the LinkedIn author cited at the top of the article, I do believe CT has many important benefits.  The next article will discuss skills and propensities that we can all develop.