In this article by John Sweller, he argues that critical thinking is unteachable:
“Cognitive load theory assumes that, for example, critical thinking is biologically primary and so unteachable. We all are able to think critically if we have sufficient knowledge stored in long-term memory in the area of interest.
A car mechanic can think critically about repairing a car. I, and I dare say most of you reading cannot. Teaching us critical thinking strategies instead of car mechanics is likely to be useless.”
Sweller is referring to forms of teaching critical thinking that, “place a heavy emphasis on learning new problem solving or thinking strategies.”
This is not a claim unique to cognitive load theory researchers. Dan Willingham, a cognitive scientist from the U.S. has made similar claims:
“Can critical thinking actually be taught? Decades of cognitive research point to a disappointing answer: not really.”
We can learn heuristics such as, ‘look at an issue from multiple perspectives,’ but if we do not know what these multiple perspective are then we cannot do so. We might add that if we do know what they are then we are probably looking at the issue from multiple perspectives already.
However, it is important to note that both Sweller and Willingham are referring to critical thinking as a general purpose skill in a similar way to how the Australian Curriculum describes it as a ‘general capability’.
If we re-examine the Sweller quote, it is clear that he believes car mechanics can think critically about repairing cars and that this is not an innate ability because others do not possess it. So they must have learnt something.
What have they learnt? They have learnt ‘sufficient knowledge’ about cars and this knowledge can, in principle, be taught.
So it is possible to learn critical thinking, it’s just that you learn it within a specific domain.
I would go further. My view is that there is a trade-off similar to Heisenberg’s uncertainty principle: The more widely applicable the knowledge, the less useful it is and the more useful the knowledge, the less widely applicable it is.
This is not a universal, it is lumpy, with some kinds of knowledge unlocking more doors than others. For instance, the ability to rearrange linear equations in mathematics has a very wide range of applications in secondary school, both within mathematics and in other fields like physics. This lumpiness can help guide curriculum decisions.
So no, you cannot really learn a general skill of critical thinking. To the extent that one exists, the majority of us probably develop it without instruction. But you can learnt a lot about the world that will help you think more critically about it.