Sometimes you read a study that doesn’t really tell you anything new, and yet sharpens things considerably. This is one of those. Johanna Grimm and Tobias Richter looked at whether you can train students to think more “rationally”. In practice, that means relying less on intuition, thinking more systematically, and avoiding common cognitive biases more effectively. The intervention was short, about twenty minutes, with some explanation of biases and a set of exercises.

The result? Students did become better at rational thinking. Not a huge effect, but a clear one. Nothing too surprising there.

But then comes the more interesting part. The researchers also asked whether this improvement would carry over to a closely related task: evaluating arguments. After all, if you are less prone to bias, you might expect to become better at judging whether a line of reasoning holds up.

That, however, did not happen. Students who received the training did not perform better on argument evaluation than those in the control group. Both groups improved slightly, most likely because of practice effects, but the trained group did not outperform the others.

That may not sound spectacular, but it is quite telling. It almost perfectly illustrates a point we made years ago in Urban Myths about Learning and Education. Many skills are far less generic than we tend to assume. They are tied to specific content, contexts, and types of tasks. You get better at what you practise, but that improvement does not automatically spill over into other domains.

In More Urban Myths about Learning and Education, we discussed this further in terms of transfer. The idea that learning A will make you better at B, especially when A and B seem closely related. In reality, transfers rarely happen on their own. It usually needs explicit support.

What this study shows is how stubborn that problem is, even when the distance between A and B is small. Rational thinking and argument evaluation are not worlds apart, yet the transfer still fails to materialise. The training does something, but its effects remain quite narrow.

For education, that matters. If we want students to become better at evaluating arguments, then that is what we need to practise. Not once, not in isolation, but across different contexts and with meaningful content. It will not simply emerge because we have worked on something adjacent like “critical thinking”.

In the end, this study is a useful reminder of something quite simple: we tend to get what we train, not what we hope will come along for free.