Wason selection task: what it is and what it shows about the reason

For millennia human beings have been considered to be analytical and rational animals., that we can hardly be wrong when we think in a reasoned and deep way about a problem, be it mathematical or logical.

Although there may be cultural and educational differences, the truth is that this has come to be assumed as something proper and inherent to the human species, however, to what extent is it true?

Peter C. Wason had the fortune, or the misfortune, depending on how you look at it, to verify with a very simple task that this was, simply and simply, not entirely true. With a very easy task, called the Wason selection task, this researcher was able to observe how many of our apparently analytical decisions are not.

Here we are going to explain what this task consists of, how it is solved and to what extent the context influences its correct resolution.

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What is Wason's selection task?

Imagine that there are four cards on a table. Each of them has a number on one side and a letter on the other. Let's say that right now the cards are arranged in such a way that they look like this:

E D 2 9

They tell us that if there is the letter E on one side, an even number will be found on the other, in this case, 2. What two cards should we raise to confirm or deny this hypothesis?

If your answer is the first and third letter, you are wrong. But don't get discouraged, since only 10% of people who are presented with this task get to answer correctly. The correct action was to turn the first and the last of the cards, since they are the ones that allow us to know if the previous statement is true or not. This is so because when the card E is picked up, it is checked if there is an even number on the other side. If this were not the case, the statement would not be correct.

This example shown here is the task proposed by Peter Cathcart Wason in 1966 and is what is called the Wason Selection Task. It is a logical puzzle in which people's reasoning ability is put to the test. Human thought follows a series of steps to reach conclusions. We elaborate a series of approaches whose premises allow us to reach conclusions.

There are two types of reasoning: deductive and inductive. The first is the one that occurs when all the initial information allows reaching the final conclusion, while in In the case of inductive reasoning, there is concrete information that allows us to obtain new information, but in terms that are not absolutes. In the case of the Wason task, the type of reasoning that is applied is deductive, also called conditional reasoning. Therefore, when solving the task, the following must be taken into account:

The D card should not be turned up because, regardless of whether or not it has an even number on the other face, the statement is not refuted. That is, they have told us that on the other side of the letter E there should be an even number, but they have not told us at any time that any other letter cannot have that same type of number.

You should not pick up the card with the 2 since if there is an E on the other side, it verifies the statement, but it would be redundant since we would have already done it when picking up the first card. In the event that there is no E on the other side, it does not refute the statement either, since it has not been said that an even number must have the letter E on the other side.

Yes, the last face must be raised with the 9 because, in the event that an E is found on the other side, it refutes the statement, since it means that it is not true that in every letter with the letter E there is an even number to the other side.

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The matching bias

The fact that most people fail the classic Wason task is due to matching bias. (matching bias). This bias makes people turn those cards that only confirm what is said in the statement, without thinking about those that could falsify what is said in it. This is somewhat of a shock, since the task itself is quite simple, but it is displayed in a way which, in the event that the statement is abstract, causes it to fall into the deception above commented.

This is why the Wason selection task is probably one of the most investigated of all time, since it challenges in a somewhat frustrating way the way in which we reason humans. Humans. In fact, Wason himself, in an article published in 1968, assured that the results of his experiment, which we remember were only 10% correct, were disturbing.

It has been assumed throughout history that the human species is characterized by analytical reasoning, however, this task shows that, on many occasions, the decisions that are made are made in a completely irrational way.

Context changes everything: content effect

When this test was presented in a decontextualized way, that is, speaking in terms of numbers and letters, as is the case presented here, the research showed very poor results. Most of the people answered incorrectly. However, if the information is presented with something from real life, the success rates change.

This was verified in 1982 by Richard Griggs and James Cox, who reformulated Wason's task as follows.

Participants were asked to imagine that they were policemen walking into a bar.. Their task was to verify which minors were consuming alcohol and, therefore, committing an offence. In the place there were people drinking, people who did not drink alcohol, people under 18 and people over 18. The question asked of the participants was which two groups of people should be questioned in order to do the job well and in the fastest way.

In this case, about 75% answered correctly, saying that the only way to make sure that you were not committing the aforementioned offense was to ask the group of minors and the group of people who consumed drinks alcoholic.

Another example that shows how the context makes it more efficient when answering this task is the one proposed by Asensio, Martín-Cordero, García-Madruga and Recio in 1990, in which instead of alcoholic beverages they spoke of vehicles. If a person drives a car, then he must be over 18 years of age. Putting the participants the following four cases:

Car / Bicycle / Person over 18 / Person under 18

As in the previous case, here it is clear that the card of the car and that of the Person under 18 must be turned over. In this case, 90% answered correctly. Despite the fact that the task in this case is the same, to confirm or falsify a statement, here, having contextualized information is faster and it is clearer what must be done to answer correctly correct.

It is here when we talk about the content effect, that is, the way in which human beings reason not only depends on the structure of the problem, but also its content, whether or not it is contextualized and, therefore, we can relate it to problems of the real life.

The conclusions drawn from these new versions of the Wason task were that when you reason, you make certain mistakes. This is due to more attention is paid to superficial features, especially those that are limited to confirming the abstract hypothesis raised. The context and the information of the exercise affect the correct resolution of the exercise because the understanding is more important than the syntax of the statement.

Bibliographic references:

• Asensio, M.; Martin Cordero, J.; Garcia-Madruga, J.A. and Recio, J. No Iroquois was a Mohican: The influence of content on logical reasoning tasks. Psychological Studies, 43-44, 1990, p. 35-60.
• Cox, J.R. and Griggs, R.A. Memory & Cognition (1982) 10: 496.
• Wason, P. c.; Shapiro, d. (1966). «Reasoning». In Foss, B.k M. New horizons in psychology. Harmondsworth: Penguin.
• Wason, P. c. (1971). «Natural and contrived experience in a reasoning problem». Quarterly Journal of Experimental Psychology 23: 63-71.
• Evans, J. st; Lynch, J. S. (1973). «Matching bias in selection task. British Journal of Psychology». Matching bias in selection task. British Journal of Psychology 64: 391-397.