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Thinking Fast and Slow by Daniel Kahneman

June 23, 2013

Thinking Fast and Slow

Do you want to know how your brain works? You might have to wait for another book for that. But, do you want to know more about how your conscious mind makes decisions and evaluates problems? You’re in luck! This is the book for you! Even if you don’t think you do want to know more about these things, you should probably still read this book. It’s really good.

Daniel Kahneman is a Nobel Laureate in Economics but has spent his whole life studying psychology and the processes behind decision making. Thinking Fast and Slow is about the shortcuts and tricks our own brains use to process information and decisions quickly. He defines two systems working within the brain – System 1 (the fast) and System 2 (the slow). When faced with a decision System 1 acts quickly, using associations and emotions to guide you to a decision. System 2 requires much more time and effort to operate and is, by Kahneman’s definition, extremely lazy. When there is an available answer from System 1, your “rational” mind will accept it and move on, even if it might not be correct!

Consider the following example:

If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets?
100 minutes or 5 minutes?

If you were told to answer this question immediately you, like most people, might effortlessly guess the first answer, although if you took time, focused on the question and forced your brain to think you would realize that the second is actually correct. Even if you engage your mind from the beginning and retrieve the correct answer (5 minutes), you can see how you might fall into such an easy trap and guess incorrectly. The off the cuff answer of 100 minutes comes from System 1, it tries to save time and pick what “sounds” right. It isn’t until you consciously engage System 2 that the real answer reveals itself. In situations like these System 1 can lead you astray. Kahnemen argues that if you can be aware of situations where your fast thinking may trick you, it becomes easier to catch yourself and make a wiser and more informed choice.

Kahneman warns that System 2 can be severely weakened when you are tired, hungry, or trying to retain something important in working memory. I will admit that I was extremely tired during the majority of the time I spent reading this book. Working nights at a telescope seems to have dramatically weakened my System 2 since most of the examples he gives of fast thinking vs. slow thinking (there are many such examples spread throughout the book) put my slow thinking to shame.

One of the most interesting points that the author makes, I found, was that this isn’t always a bad thing. The way our brains make associations and process information is highly non-linear, with neural networks linking concepts together in the blink of an eye. For example, look at the two word sets below and see if, for each one, you can think of a word that is associated with all three:

dive light rocket
dream ball book

When I tried this (while feeling very tired) I had a gut feeling that the first three were connected and the second three were not even though I couldn’t immediately think of the word that might work in the first case (it’s sky, by the way). Even without having to think very hard the simple yes/no answer had already been retrieved by my brain (in this case System 1’s fast action). I was suitably impressed with my fast little neurons. These are the arenas where System 1 was built to shine. Providing answers without effort and retrieving a simple answer from stored memories.

This book deals with a lot of interesting topics where these two systems can come into conflict and the biases and heuristics our minds use to make sense of the world around us. How we judge likelihood based on what comes to mind (availability heuristic), how we are more sensitive when a change is presented in terms of loss (loss aversion) or how we judge an individual as being generally favorable even if we only know a few things we like about them (halo effect). Kahneman explicitly states in the Forward that he wrote this book to influence water-cooler gossip. That seems like it might be a strange reason to write a book, but he explains that he wanted to teach the average person about why those around them either in the office or at home make choices that might seem to make no rational sense. He also tries to provide a language framework to facilitate discussions about these topics. I think it works remarkably well.

As a psychologist and a researcher of these two systems Kahneman knows very well how to present information in a way such that it is easily understood by the mind. His use of examples and stories makes this book extremely readable and I felt that I learned a lot. It’s a good introduction to general psychology and might just make you understand yourself better! Give it a read and let me know!


From → Non-Fiction

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  1. Stop Thinking and Stop To Think | The Development Guy

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