Does this headache medicine work? Can I lose weight by dieting? Are the government’s measures to combat inflation effective? To answer any of these questions, humans use our ability to reason about causes and effects. However, psychological research shows that we often make mistakes such as perceiving non-existent causal relationships. This is a phenomenon known as “causal illusions .” These illusions can lead us to believe in pseudo-medicines, miracle products and supernatural agents, so it would be very convenient to design good educational workshops to minimize their impact.

To address this problem, a team of researchers from the universities of Deusto, Barcelona and Granada designed an educational workshop aimed at preventing causal illusions. The workshop was implemented in forty schools across Spain and involved more than 2,000 students between the 2nd and 4th years of compulsory secondary education. Its results have been published as a scientific article in the journal Royal Society Open Science .

Instilling the logic of experimentation

The educational workshop revolves around the idea that in order to test the effectiveness of a product, it is essential to observe both what happens when using it and what happens when not using it. In other words, it is necessary to follow the logic of experimental control.

This concept, common in clinical trials and scientific experiments, is not intuitive to most people . For example, to know if a headache remedy is good, we often settle for observing how we feel after taking it. In reality, what we should do is use it some days and not others, so that we can compare how we feel after using the remedy and after not using it.

This is the logic of the experimentation that was addressed in the intervention.

The workshop was conducted in three phases, lasted an hour and a half and took place in the classroom. In the first phase, students were introduced to a miracle product , a ring supposedly capable of improving cognitive and motor skills. It was promoted using strategies similar to those of many miracle products, including scientific jargon and emotional appeals.

In addition, students were given the opportunity to test a prototype of the ring while performing strength or balance tests, or solving puzzles. The catch was that all of these activities were always performed with the ring on, or in situations that did not allow for a clear test of its effectiveness. In other words, from a scientific point of view, these tests lacked a good control condition. At the end of this phase, most of the students were convinced that the ring worked.

In the second phase of the workshop, it was revealed that the ring had no special properties and the errors in reasoning that had been made were explained. Here, the importance of proper experimental control was emphasized. Since the students had been fooled previously , they were motivated to learn how to avoid making the same mistake in the future.

In the third phase, the students participated in a computer-based task similar to a video game. In it, they pretended to be doctors testing a drug on fictitious patients. Sometimes the drug didn’t work at all, but the students could only figure this out if they understood the importance of comparing patients who had taken the drug with those who hadn’t. Otherwise, it was easy to develop a causal illusion and mistakenly believe that the drug worked , since the game was programmed so that there were very frequent cures whether or not the patients took the drug.

Did the workshop work?

To test whether the workshop worked, we divided the students into two groups, with half of them completing the computer task without having previously attended the workshop. In other words, they served as a control group. In order not to deprive them of the educational benefits of the workshop, these students in the control group completed the workshop after the computer task, when it could no longer influence the measurement of causal illusion.

The results of this large-scale study confirm those of a previous investigation and demonstrate that the workshop was useful in preventing causal illusions in the video game.

That is, the adolescents who had completed the workshop before playing the video game were able to transfer what they had learned to this task, showing a lower incidence of causal illusion than the control group and therefore discovering that the drug was not working.

Not only that: a new measurement six months later indicated that the workshop effect can be maintained in the long term, even by changing the details of how the causal illusion is measured.

Ultimately, these types of educational interventions can be useful to encourage critical thinking and reduce causal reasoning errors, which could protect us from some dangerous beliefs such as those that promote the use of pseudomedicines .

Author Bios: Fernando Blanco Bregon is Professor of Social Psychology at the University of Granada, Helena Matute is Professor of Psychology at the University of Deusto, Itxaso Barber Shop is Associate Professor, Faculty of Psychology at the University of Barcelona and Naroa Martinez is a Postdoctoral Researcher at the University of Deusto