Can thinking be taught? 341 studies say yes — and by roughly this much
The honest answer is not “yes, transformatively”. It is “yes, measurably, if you do it deliberately” — and the studies are unusually clear about which methods carry the effect.
How big is 0.30, in plain terms?
Effect sizes are the least intuitive number in education research, so here is the translation. An effect of 0.30 means that if you lined up children who were taught this way against children who were not, the taught group would come out ahead in a clear majority of head-to-head comparisons — about 6 times in 10, rather than the 5 you would get by chance.
That is not a miracle. It is roughly the size of effect that separates a good year of teaching from an average one, and it compounds if you keep it going.
What carried the effect
This is the part that gets left out of the headline. The review did not find that all methods of teaching thinking work equally. It found large differences depending on how it was done.
The reviews did not find that teaching thinking works. They found that teaching it deliberately works, and that hoping does not.
The catch, printed in full
Two things in this literature should keep anyone honest. First, the results are heterogeneous: the average hides programmes that did nothing and programmes that did a lot. Second, and more importantly for parents, the pooled reviews of children’s thinking programmes found no convincing evidence that gains persisted at follow-up after short interventions.
That is not an argument against teaching thinking. It is an argument against six-week courses, bootcamps and anything that promises to be finished. Thinking behaves like fitness: it responds to training and it decays without it.
Name the move. A child who knows they are “checking whether that must be true” can do it again on purpose.
The most evidence-backed thing you can do at home is ask a child to explain, and then disagree gently.
The evidence rewards duration. Anything sold as a finished course is fighting the strongest finding in the field.
Questions parents actually search for
Can critical thinking really be taught?
Yes, and it is one of the better-evidenced claims in education. A meta-analysis of 341 effect sizes found an average improvement of about 0.30 standard deviations from deliberate instruction, across all education levels and subject areas.
What is the best way to teach a child to think?
According to the same review: dialogue, authentic problems and mentoring. In practice that means asking children to reason out loud, giving them problems with genuine ambiguity, and having someone who models the moves.
Do brain-training apps work?
Mostly they make children better at the app. What distinguishes the effective programmes in the research is transfer to tasks that were never practised — which some pooled studies do find, and which most commercial games never test.
How long does it take?
Longer than any product wants to admit. The uncomfortable finding is that short programmes’ gains often faded at follow-up, which is why steady practice over years beats an intensive burst.
One finding a week, in plain words, with its caveat attached
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