Thinking, Fast and Slow

Robert is reading Daniel Kahneman’s book, Thinking, Fast and Slow, which was published in 2011. Mr. Kahneman is a fancy pants professor of psychology at Princeton, oh, and he also won the Nobel Prize in Economics.  He studies decision making and stuff like that.

One of the central current notions of judgment and decision-making is the existence of so-called System 1 and System 2 thinking.  System 1 thinking being automatic and intuitive “thinking” that helps us make decisions.  System 2 thinking being the more intellectual workhorse type of thinking that kicks in when the brain cannot jump to a conclusion through use of System 1. For example, consider the following multiplication problems:

2 x 4

17 x 24

In answering the first problem, everyone uses System 1 thinking to snap to an answer automatically. But in order to answer the second problem, you must engage System 2 and calculate an answer.

Another central notion is that System 2 is very lazy.  We all resist its use, and it will only kick in when System 1 cannot consider (and often reconstruct wholesale) the question in a way that allows it to snap to an answer (often with shockingly little information).  To demonstrate the laziness of System 2, consider the following problem.

A bat and ball cost $1.10.
The bat costs one dollar more than the ball.
How much does the ball cost?

If you answered 10 cents, then you are like many people.  You are also wrong.  The answer is 5 cents. The striking thing is that it is very easy to check one’s answer when considering this question and confirm that it is correct or incorrect (e.g., obviously, if the ball cost 10 cents, then the bat would not cost one dollar more than the ball).  But when asked what is known as the bat-and-ball problem, most people will avoid even a small investment in making the check, which would entail System 2 thinking.  Over 50% of undergraduate students at Harvard, MIT and Princeton will not make it. People who answer 10 cents appear to be ardent followers of the law of least effort.  People who avoid that answer appear to have more active minds. But the thought experiment is not really about determining intelligence.  It is about demonstrating how lazy a certain part of all our minds is.

The bat-and-ball problem also describes another theory written about in Kahneman’s book (and which Robert finds pretty fascinating).  Spinoza wrote about the theory of believing and unbelieving. According to Kahneman, modern psychologists have proposed that understanding a statement must begin with an attempt to believe it: you must first know what the idea would mean if it were true. Only then can you decide whether or not to unbelieve it. The initial attempt to believe is an automatic operation of System 1, which involves the construction of the best possible interpretation of the situation.  Paraphrasing Kahneman, even a nonsensical statement will evoke initial belief. Try the following: “Whitefish eat candy.” Your System 1 engages in an automatic process of associative memory to find links between the two ideas (i.e., fish and candy) that would make sense of the nonsense.  During this process, it can be said that you believe that whitefish eat candy until your System 1 exhausts itself in trying to automatically confirm the statement. Once your System 1 is exhausted, your System 2 kicks in and is responsible for the unbelieving process which leads to a conclusion that the statement is false.

Very cool book full of stuff like this.  The problem is that after about 100 pages, the reader has very little confidence left in the reasoning abilities of mankind.  The price of a good book, Robert supposes.