The Undoing Project by Michael Lewis


One of Michael Lewis’s early books is Moneyball, about efforts to find more accurate ways to predict how well an individual baseball player or baseball team will perform. The subject of this book is the work of two Israeli psychologists, Daniel Kahneman and Amos Tversky, that was the background of those efforts to make more accurate judgments and to improve decision-making. The two psychologists were interesting, rare characters whose friendship and collaboration was intense, making this a wonderful story.

The two observed errors in the way people make judgments and described these common errors in interesting ways. Here’s one:

The Linda Problem. Three sentences describe Linda:  “She is 31, outspoken, single, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti-nuclear demonstrations.”

Participants are then asked, “Which is more probable?”

  1. Linda is a bank teller.
  2. Linda is a bank teller and is active in the feminist movement.

Participants ranged from college students to experienced statisticians. They found that 80% of the respondents chose the second sentence. Something about the three sentences moves people to think that two things about an unknown person is more probable than just one.

Another interesting concept involves how we compare objects to say how similar they were to each other. It turns out you might say one thing is like another, but you would not say the reverse is true.  Amos said people say North Korea is like Red China, but no one would say Red China is like North Korea. Tel Aviv is like New York, but New York is not like Tel Aviv. We might say my love is as deep as the ocean, but not the reverse, because the ocean conveys great depth, while that is not the most notable characteristic of love.

If you flip a coin 200 times, it will land tails up 50% of the time. People believe that if it lands heads up six times in a row, it’s more likely to be tails on the next flip. But in fact, each time you flip it, the chance of it being tails remains at 50%.

A firehose of information came pouring out of this audiobook, just as it did from the minds of those two brilliant men. One concept I came away with is that we should not trust our untested thoughts and assumptions, especially relating to probability.

Michael Lewis, The Undoing Project, W.W. Norton, 2017, 362 pages (I listened to the audiobook). Available in the public library.


Recent Posts


Blogs I Like