In an article where he quotes the psychologist Peter Cathcart Wason, the writer David Leonhard of the New York Times wrote about the Confirmation Bias phenomenon which asserts that we are biased to seek what agrees with our beliefs and that we do not want to find out that we are wrong. I strongly recommend this article for all educators, parents and students as it highlights a very important cognitive phenomenon. You can access the article through the link The article describes a test that Wason performed which illustrates the Confirmation Bias phenomenon. I suggest that you access the link and take the test before you read Leonhard's article or the commentary below.

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I tried the test on two separate occasions. On the second attempt I had forgotten the correct solution that I had encountered on the first attempt, and I found myself repeating the same mistake that I had commited before. On both attempts my brain first went into autopilot, or in more academic terms, System 1 Mode of Thinking (Kahneman, 2013, pp 19-30), which provided me with a quick apparent solution. What I immediately saw was that the rule of a Geometric Sequence of ratio 2; the first number is arbitrary, the second number is double the first, and the third number is double the second; and most probably you went through the same experience. System 1 has some characterisitcs one of them is that it "operates automatically and quickly with little or no effort" (Kahneman, 2013, p 105). Another caharaterisitic of it is that "it computes more than intended" Ibid., hence the explanation why my brain chose the more difficult Geometric Sequence solution rather than the much simpler rule which the author had meant; i.e. that simply the first number is arbitrary, the second number is greater than the first, and the third number is greater than the second .

In the first attempt, a couple of years ago, I did not check enough although I had constantly emphasised to my colleagues and to my students that we should be careful with making decisions because our decisions are mostly based on assumptions that we make unconsciously, and because we tend to trust our assumptions. I teach that we should make the effort to think out of the box, check our assumptions very thoroughly before making decisions. I also repeatedly maintained that in order to understand a statement, or a rule as in this case, it is not enough to consider what we think it says, but it is important also to check what it may not be intended to say. Hence I continually urge my colleagues and my students to challenge their assumptions, to think critically and creatively, and to be very careful before making conclusions or decisions. Nevertheless I was strangley too confident to check! To assume and not check well enough, is a common strategy which is at the root of many of the mistakes that we make every day.

When I tried the same test again today; i.e. during my second attempt, my brain strangely made exactly the same assumption as before. And again, I started checking its correctness rather than including checks for its shortcomings. But what helped me out this time is that I remembered that in my earlier reading of that article I had learnt that there was something wrong with what I was doing, but I had forgotten what was wrong with it. I remembered that the rule is not the one I am assuming, but I found it difficult to remember, or rediscover, the correct rule, or even any clue related to its properties. During this second attempt I had to sit back and jog my memory and ask myself about where I am going wrong. I consciously put my brain's System 2 thinking (Kahneman, 2013, pp 19-30) to work. I worked hard to overcome System 1 and to avoid the confirmation bias. Suddenly my previous experience came to help with a Eureka feeling and I remembered that I had learnt that we should be careful not to be restrict our thinknig to an easily-noticed special case, but that we should rather explore the axistence of some more comprehensive general case. I somehow knew that the secret to the solution lied there. I started thinknig of a rule that encompasses the geometric sequence rule, but which is more general. After a few minutes I ''rediscovered'', or remembered, the simpler solution.

My experience, and most probably yours, were good illustrations of how our congitive systems work and of Kehnman's and Wason's findings and this knowledge is very useful for our everyday life and professional decision making practices. Confirmation bias "bedevils companies, governments and people every day" (Leonarhdt, 2015), and I like the example that David gave about Vice President Dick Cheney, who in 2003, before they invaded Iraq, predicted that the Americans “...will ... be greeted as liberators” by the Iraqis Ibid.

Read again David's important warnings to us:

"When you want to test a theory, don’t just look for examples that confirm it

... When you’re considering a plan, think .... about how it might go wrong

 .... start by being willing to hear no

And even if you think that you are right, you need to make sure you’re asking questions that might actually produce an answer of no". 

These is are very essential strategies for success.

Saad Abou-Chakra



Leonhardt, D., & You. (2015, July 2). A Quick Puzzle to Test Your Problem Solving. The New York Times. Retrieved from

Kahneman, D. (2013). Thinking, Fast and Slow . Doubleday Canada, A Dvision of Random House of Canada Limited, pp 19-30