Why good thoughts block good thoughts from them / Miriam Bialich and Peter McLeod

When we are working on a problem, the mind's tendency to stick to familiar ideas can blind us to more successful solutions.

In a classic experiment conducted in 1942, American psychologist Abraham Luchins asked volunteers to perform some simple mathematical calculation while imagining a jug of water. If they were given three empty containers, for example, each of which had a different capacity - 21, 127 and 3 volume units of water - the participants had to think about how water could be transferred between the containers, so that they could measure an amount of exactly 100 volume units. They could fill and empty each urn as many times as they wanted without limit, but they had to fill each urn exactly to its full capacity. The solution was to first fill the second urn, which has a capacity of 127 units, then empty it into the first urn, thus eliminating 21 volume units, and being left with 106 units, and finally fill the third urn from it twice and thus get rid of another 6 units, so that the second urn will be given up 100 volume units. Luchins presented his volunteers with several other problems that could basically be solved in the same three steps; They solved them easily and quickly. But when he then presented them with a problem whose solution was simpler and faster than that of the previous tasks, they failed to notice this.

This time, Luchins asked the participants to measure 20 volume units of water using containers whose capacity was 23, 49 and 3 liquid volume units. The solution is obvious, right? Simply fill the first jar and empty it into the third: 20 = 23-3. But many of the people in Luchin's experiment insisted on solving the easier problem in the former way, by emptying the second jar into the first, and then twice into the third jar: 20= 49-23-3-3. And when Luchins gave them a task that had a solution in two steps, but it was not possible to solve it in the three steps that the volunteers were used to, they gave up and said that it was impossible.

The experiment with the water jug ​​is one of the most famous examples of the Einstellung effect: the persistent tendency of the human mind to stick to a known solution to a problem, the first that comes to mind, and to ignore alternatives. Often, this way of thinking is indeed a useful strategy. Once you have found a successful method for peeling garlic, for example, there is no point in trying several other methods every time you need to peel a clove of garlic. The problem with this cognitive shortcut is that it sometimes blinds people's eyes to solutions that are more effective or suitable than the solutions they are familiar with.

Psychologists who continued Luchins' early work replicated the Einstellung effect in many different laboratory studies, both working with novices and experts who had practiced a wide range of mental abilities, but were unable to clarify how and why the effect occurs. Recently, by recording the eye movements of highly skilled chess players, we were able to solve the mystery. It turns out that people under the influence of this cognitive shortcut are literally blind to certain details in their environment that could provide them with a more helpful solution. New research also shows that many cognitive biases discovered by psychologists over the years, biases manifested in courts or hospitals, for example, are actually versions of the Einstellung effect.

Back to the beginning

Since at least the early 90s, psychologists have studied the Einstellung effect by recruiting chess players of varying skill levels, from amateurs to masters. In these experiments, the researchers presented players with certain arrangements of playing pieces on virtual chessboards, and asked them to reach checkmate in as few moves as possible. In our studies, for example, we provided expert chess players with scenarios that allowed them to achieve mate using a well-known sequence of moves called smothered mate. In this five-step maneuver, the queen is sacrificed in order to draw one of the opponent's pieces to a certain square so that it later blocks the king's escape route. Players also had the option of obtaining a matt in just three moves, but in a much less familiar sequence of moves. As happened in Luchin's water jug ​​experiment, most players failed to find the more efficient solution.

During some of these studies, we asked the players what they were thinking during the game. They said they had found the met-choke solution and insisted on claiming that they had been looking for a shorter solution, but to no avail. However, these verbal reports did not make it clear to us why they were unable to find the faster solution. In 2007 we decided to try something a little more objective: to track eye movements using an infrared camera. The information that will be collected, which part of the board the players looked at and for how long they looked at different parts of it, will tell us unequivocally which aspects of the problem received their attention, and which aspects they ignored.

In this experiment, we followed the gaze of five expert chess players as they evaluated a board with a problem that could be solved by both the five-step checkmate maneuver and the shorter three-step maneuver. After an average of 37 seconds, all players strongly argued that the checkmate maneuver was the fastest way to corner the king. But when we presented them with a board with an arrangement of tools that could only be solved by a three-step maneuver, they found it without difficulty. And when we told the players that the same quick fix was possible on the previous board, they were shocked. "No, that's not possible," said one of them. “This is another problem; She must be different. I would notice such a simple solution." It is quite clear that the possibility of the solution in a meta-choke is enough to hide alternative solutions from their eyes. In fact, the Einstellung effect was so strong that it reduced expert chess players to the level of much weaker players.

The infrared camera revealed that even when the players said they were looking for a faster solution, and they did believe they were doing so, they actually did not look away from the slots they had already identified as part of the meta-choke maneuver. In contrast, when presented with the problem with the only solution, the players first looked at the squares and the tools necessary for the meta-choke maneuver, and once they realized it wouldn't work, they turned their gaze to other squares and quickly found the shorter solution.

basis for bias

In October 2014, Heather Sheridan of the University of Southampton in England and Eyal M. Rheingold of the University of Toronto published studies that supported and complemented our eye-tracking experiments. They presented 17 novice and 17 expert chess players with two different situations. In one scenario, a well-known maneuver to achieve a met, such as a met-choke, was a successful solution, but less successful than another solution that was not obvious, but was the best. In the second scenario, choosing the more familiar sequence of steps was an obvious mistake. As happened in our experiments, from the moment the amateurs and professional chess players "locked in" on the familiar and successful maneuver, their eyes hardly turned towards the squares that would have provided them with a hint of the better solution. But when it was clear that choosing the well-known sequence would be a blunder, all experts and most beginners noticed the better alternative.

The Einstellung effect is not limited to controlled laboratory experiments or even to mind-challenging games like chess. It actually lays the foundation for many cognitive bias situations. The English philosopher, scientist and thinker Francis Bacon wrote extensively and in particularly rich language about one of the most common forms of cognitive bias in his book from 1620, Novum Organum (Latin: "new instrument", he meant science as a tool or means of knowledge): "Human understanding, When she has adopted an opinion... she brings all other things to support her and settle with her. And even if there are more cases, of greater weight, that support the opposite opinion, she ignores them or rejects them with contempt, or she finds some reason to push them away from her and abandon them... people... notice the cases that justify them, but the cases where their opinion is unfounded, even if these Occurring with far greater frequency, they are ignored and passed over as if they did not exist. This damage paves the way for him, with much greater sophistication and cunning, into philosophy and the sciences, where the first conclusion colors everything that follows it and imposes on him unanimity.

In the 60s of the 20th century, the English psychologist Peter Wesson gave a name to this particular bias: "confirmation bias". In controlled experiments, he showed that even when people try to test their theories objectively, they tend to look for evidence that supports their ideas, and ignore anything that contradicts them.

For example, in his book There is no measure for man (In the original: The Mismeasure of Man, see Or in Hebrew, published by Dvir, translated by Amos Carmel) Stephen J. Gould from Harvard University reanalyzed data cited by researchers in an attempt to estimate the relative intelligence of members of different races, social classes and genders, by measuring the volume of the skulls or weighing their minds; And this is assuming that there is a correlation between intelligence and brain size. Gould exposed data distortions on a massive scale. When it turned out that the brains of the French were smaller on average than the brains of the Germans, the French neurologist Paul Broca tried to explain the difference by claiming that it was the result of differences in the average body size between citizens of the two nations, since he could not accept that the French were less intelligent than the Germans. And yet, when he found that women's brains were smaller than men's, he did not apply the same body-size correction to them, for he had no difficulty in accepting the idea that women were less intelligent than men.

Gould came to a somewhat surprising conclusion, according to which Broca and others like him were not as deserving of reproach as we tend to think. "In most of the cases discussed in this book we can be fairly certain that the biases . . . operated unconsciously, and that the scientists believed that they were laboring only to seek the pure truth," Gould wrote. In other words, just as we saw in our chess experiments, the ideas that were familiar to Broca and his contemporaries blinded them to errors in the judgment and logic of their thinking. Herein lies the real danger of the Einstellung effect. We may believe that our thinking is free and unbiased, and we are completely unaware that our brain selectively directs our attention away from aspects of the environment that can make us think new thoughts. Any data that doesn't match the solution or the theory we've already adhered to is ignored or rejected.

The hidden nature of confirmation bias has dire consequences in everyday life, documented in studies of decision-making by doctors and juries. In a review of errors in medical thinking, physician Jerome Gropman noted that in most cases of misdiagnosis, "physicians did not fail because of ignorance of the clinical facts; But they missed the diagnosis because they fell into cognitive traps." When doctors "inherit" a patient from another doctor, for example, the diagnosis of the first doctor may blind the second doctor to important and contradictory details of the patient's health, which could change the diagnosis. It is easier to accept the diagnosis that is already in front of their eyes than to rethink the whole situation. Similarly, radiologists reviewing chest X-rays often fixate on the first abnormality they see and overlook other signs of disease that should be obvious, such as swelling that may indicate cancer. If these secondary details are presented alone, separate from everything else, radiologists notice them immediately.

Studies in the same matter have suggested that jurors in a trial begin to decide about a person's guilt or innocence long before they see all the evidence. Their first impression of the accused in turn affects them and causes them to change the weight they attribute to the evidence presented later, and even changes their memory regarding evidence they saw before reaching their decision. In the same way, if a person interviewing a job candidate finds the interviewee attractive in appearance, he or she will evaluate the candidate's intelligence and personality in a more positive light, and vice versa. These biases are also driven by the Einstellung effect. It is easier to make up your mind about a person if you hold a consistent position about him, than to try to sift through conflicting evidence.

Can we learn to resist the Einstellung effect? Maybe yes. In our chess experiments and the follow-up experiments done by Sheridan and Reingold, some highly skilled experts, such as international rabbis, did notice the optimal but least predictable solution, even when a slower but more familiar sequence of moves was possible. This shows that the more someone is an expert in his field, whether it is chess or science or medicine, the more immune he is against cognitive bias.

But no one is completely immune; Even the most international artists failed when we presented the problem in a complicated enough way. Another way to resist the Einstellung effect is to deliberately remember that you are prone to it, and to be on guard. When examining, for example, the evidence regarding the relative contribution of human-made greenhouse gases to the rise in temperature on Earth compared to naturally occurring greenhouse gases, remember that if you think you already know the answer, you will not evaluate the evidence objectively. Instead, you will notice the evidence that supports the opinion you have already formed and appreciate it as stronger than it really is, and will also be easier for you to remember, than the evidence that does not support your position.

We must try to learn how to accept our mistakes if we sincerely seek to improve our ideas. The English naturalist Charles Darwin thought of an incredibly simple and effective method that allows you to do exactly this. And so he wrote: "For many years... I adopted a golden rule, which says that whenever I come across a published fact, an observation, or a new thought that is contrary to my general results, I must put it in writing immediately and without delay, because I have realized from my experience that facts and thoughts Those tended to slip from my memory much more easily than those that were my priority."

Credit: Danny Schwartz

Much more than meets the eye

The intellectually challenging game of chess has turned out to be a great way for psychologists to study the Einstellung effect, the brain's tendency to stick with solutions it already knows rather than looking for solutions that might be better. Experiments have shown that this cognitive bias literally changes the way even expert chess players see the board in front of them.

See animations of chess moves at:

http://cognition.uni-klu.ac.at/chess/einstellung.htm

__________________________________________________________________________________________________________________________________________________________________

About the authors

Merim Bialić is a professor of cognitive science at the University of Klagenfurt in Austria and a senior associate lecturer at the University of Tübingen in Germany. In his research on the Einstellung effect, he received an award from the British Psychological Society for an outstanding research contribution to a PhD in psychology in 2008.

Peter McLeod is Emeritus Fellow of Queen's College, University of Oxford. He is the chairman of the Institute for Neuroscience and Artificial Intelligence in Oxford.

in brief

The Einstellung effect is the brain's tendency to stick to the most familiar solution to a problem and stubbornly ignore alternative solutions.

Psychologists have known about this mental phenomenon since the 40s, but only now have they come to a solid understanding of how it occurs.

In recent eye-tracking experiments, familiar ideas blinded chess players to areas of the chessboard that could provide clues to better solutions.

Peter McLeod is Emeritus Fellow of Queen's College, University of Oxford. He is the chairman of the Institute for Neuroscience and Artificial Intelligence in Oxford.

More on the subject

Why Good Thoughts Block Better Ones: The Mechanism of the Pernicious Einstellung (Set) Effect. Merim Bilali´c, Peter McLeod and Fernand Gobet in cognition, Vol. 108, no. 3, pages 652-661; September 2008.

The Mechanism and Boundary Conditions of the Einstellung Effect in Chess: Evidence from Eye Movements. Heather Sheridan and Eyal M. Reingold in PLoS ONE, Vol. 8, no. 10, Article No. e75796; October 4, 2013. www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0075796

Secrets from the mind of an expert, Philip A. Ross, Scientific American Israel, December 2006-January 2007.

The article was published with the permission of Scientific American Israel