Critical thinker, heal yourself

Can Sweller and Willingham survive a savaging by the University of Queensland's Dr. Peter Ellerton?

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“Dismissing inquiry as unnecessary or unhelpful is therefore both hasty and slothful,” suggests Dr Peter Ellerton as part of his defence of teaching critical thinking skills. In this case, the hasty sloth in question is John Sweller, founder of cognitive load theory, but Ellerton has equally harsh words for cognitive scientist, Daniel Willingham.

Two years ago, Ellerton wrote a piece for The Conversation in which he argued the case for teaching critical thinking. Ellerton referred to Philosphy for Children as a model approach for doing this. Ellerton’s article followed a previous one in 2015 that made similar claims and where Ellerton and I had an exchange of views in the comments that you can read for yourself and that is still largely valid.

So, I may be partly responsible for the way Ellerton has gone after both cognitive load theory and Willingham, because I have drawn on both in my criticisms of Ellerton’s assertion that we should spend curriculum time teaching students ‘how to think’.

In his new article, to be published in the journal Thinking Skills and Creativity in March this year, Ellerton repeats a pattern that has been apparent throughout all of the preceding discussions. Although he wants us to accept the premise that schools should teach critical thinking, he doesn’t appear to feel the need to provide compelling evidence to support this point. Instead, he views the burden of proof as lying with sceptics to define critical thinking in a way that satisfies him and then demonstrate that it cannot be taught.

The question of definitions is particularly extraordinary because although he criticises the definitions of critical thinking used by Sweller and Willingham, he offers no definition of his own. It reminds me of Twitter…

Ellerton has a strange take on Geary’s theory of evolutionary educational psychology. Although he is correct to suggest that Sweller views abilities that we commonly identify with critical thinking as ‘biologically primary’ (abilities we have evolved to acquire without the need for explicit teaching), Ellerton equates this with general intelligence and then makes a series of claims off the back of that. I’m not sure such an equivalence is correct. I haven’t read Sweller’s views on this, but my take would be that intelligence is related more to working memory capacity. Bar rare cases of cognitive impairment, I would expect virtually everyone to develop the biologically primary problem-solving strategy of means-ends analysis. This is the strategy of evaluating a problem solving move in terms of whether it takes the problem-solver closer to the end goal. As such, differences in biologically primary knowledge are unlikely to account for differences in critical thinking performance. Instead, differences in performance will be caused by differences in relevant knowledge.

Ellerton seems to have badly misunderstood one of Willingham’s arguments. As I have pointed out before, including to Ellerton, Willingham suggests that critical thinking, “is a type of thought that even 3-year-olds can engage in—and even trained scientists can fail in.” I interpret that to mean that a 3-year-old can think critically about a subject they know a lot about - such as the distribution of treats among friends - whereas trained scientists can often fail in reasoning when they venture into a different field. In the latter case, I’m reminded of Linus Pauling, a Nobel prize-winning chemist who, in his later years, advocated for the medical benefits of vast doses of Vitamin C.

However, Ellerton remarks that, “It is difficult… to reconcile claims that critical thinking requires deep discipline knowledge with the success of a three-year-old. It is also unclear how a trained scientist, presumably steeped in discipline knowledge, can get it so wrong.” Ellerton has the wrong end of the stick.

One of the key issues in discussions of critical thinking is its transferability. If we can demonstrate that teaching students how to solve, say, logic problems not only makes them better at solving logic problems but improves performance in other tasks across different domains, then this would be a high-impact set of concepts to teach. If all it does is make students better at solving logic problems then 1) it is restricted to the domain of logic problems and 2) it is only as valuable as the ability to solve logic problems is valuable. So, this is the key issue we need to resolve. If supposed critical thinking skills are entirely nested within domains of knowledge then they are just a part of that domain of knowledge and should be taught as such. They are not grandiose thinking skills and we cannot flatter ourselves that we are somehow teaching students ‘how to think’. Such a mission does not require the creation of institutes of critical thinking, it requires schools to teach standard academic subjects well.

And yet Ellerton does not seem to understand this distinction. Commenting on Willingham’s point that much of the evidence suggests that critical thinking skills do not tend to transfer to different domains of knowledge, Ellerton ponders, “Why this is problematic is not clear, since these things can be thought of as elements of critical thinking.” Not clear? It’s the main point of contention.

However, Ellerton does refer to some empirical evidence that apparently shows that attempts to teach critical thinking provide wider benefits. This should probably be a greater focus of the paper because if he could establish this, it would make a far stronger case than criticising other people’s definitions. However, this is undermined by Ellerton’s references to Philosophy for Children. There was a flurry of interest in Philosophy for Children after the UK’s Education Endowment Foundation published a 2015 study that claimed an impact on reading and maths scores. The methodology of the study was heavily criticised at the time and last year, a larger Education Endowment Foundation study concluded that Philosophy for Children had no impact on reading and mathematics ability, or social and communication skills (see the full story here). It’s not a great approach to build a case around.

We often see this with studies of critical thinking programmes. Idiosyncratically designed trials led by the researchers who developed the programme in question show positive results, but when evaluated more systematically, these results are not reproduced. A good example is Cognitive Acceleration - an approach that generated a lot of interest in the late 1980s and early 1990s but failed to replicate when tested by the Education Endowment Foundation.

In contrast, the smaller randomised controlled trials typical of cognitive load theory have generated many replications.

Ellerton does not really address the empirical basis of cognitive load theory. Instead, he makes a brief attempt to discredit it more generally as unfalsifiable. This is the old argument about germane load but he does not explore it at any great length. It seems sufficient to Ellerton to note that eminent scholars have made such a claim. Germane load has since been dropped as an explanatory factor in cognitive load theory experiments and cognitive load theory clearly makes testable predictions, such as in my own PhD study.

Finally, I could use some clarity as to whether Ellerton thinks critical thinking skills can be directly taught, are best developed through inquiry or require a mixture of the two. At times, it seems he is arguing for explicit teaching and yet there is a whole section on developing supposed scientific inquiry skills through investigations. If it is a mixture, what principles determine which methods should be used and when, and how do we know these principles are correct? As with much in the critical thinking literature, such details are left unexamined in favour of breezy mezzanine-level discussions and vague abstractions.

A better course of action for an advocate of teaching critical thinking is to accept that it is their burden to provide evidence in support of their views. The strategy of deflecting criticism by claiming the critics are not discussing true critical thinking is logically flawed and tiresome. If it needs a definition, define it. Then supply evidence. That’s how this discussion will advance.

Will it advance slowly like a sloth or more quickly like a hasty sloth? That depends on whether advocates of critical thinking can heal their own discipline first.