Daniel Kahnemans: Thinking, Fast and Slow

Thinking, Fast and Slow is a book written by Daniel Kahneman which concerns a few major questions: how do we make decisions? And in what ways do we make decisions poorly? The book covers three areas of Daniel Kahneman’s research: cognitive biases, prospect theory, and happiness. 

Kahneman defines two systems of the mind.

System 1: operates automatically and quickly, with little or no effort, and no sense of voluntary control

• Examples: Detect that one object is farther than another; detect sadness in a voice; read words on billboards; understand simple sentences; drive a car on an empty road.

System 2: allocates attention to the effortful mental activities that demand it, including complex computations. Often associated with the subjective experience of agency, choice and concentration

• Examples: Focus attention on a particular person in a crowd; exercise faster than is normal for you; monitor your behaviour in a social situation; park in a narrow space; multiply 17 x 24.

System 1 automatically generates suggestions, feelings, and intuitions for System 2. If endorsed by System 2, intuitions turn into beliefs, and impulses turn into voluntary actions.

System 1 can be completely involuntary. You can’t stop your brain from completing 2 + 2 = ?, or from considering a cheesecake as delicious. You can’t unseen optical illusions, even if you rationally know what’s going on.

A lazy System 2 accepts what the faulty System 1 gives it, without questioning. This leads to cognitive biases. Even worse, cognitive strain taxes System 2, making it more willing to accept System 1. Therefore, we’re more vulnerable to cognitive biases when we’re stressed.

Because System 1 operates automatically and can’t be turned off, biases are difficult to prevent. Yet it’s also not wise (or energetically possible) to constantly question System 1, and System 2 is too slow to substitute in routine decisions. 

We should aim for a compromise: recognise situations when we’re vulnerable to mistakes, and avoid large mistakes when the stakes are high.