Summary
Nobel prize winner Daniel Kahneman writes a book around one of his life’s central theses. The mind has two modes of thinking; he labels them System 1 and System 2, or from the title, fast and slow. The hallmarks of System 1 are its quickness, automaticity, and blindness to its own biases. System 2’s characteristics are effortful and deliberate thinking. A good example is the difference between answering the question “What is the capital of the United States?” vs the question “What is 32 multiplied by 12?” Notice how an answer for the first question flew into your head, while the second question required you to stop and slow down. An effect of System 2 requiring extra effort and slowing down means that it is lazy and will delegate work any chance it gets, which is likely why you didn’t bother to answer the 32 times 12 question but continued to read past it.
In Thinking, Fast and Slow Kahneman lays out 3 pairs. System 1 and 2 are the first pair; the second pair is what he calls Econs vs Humans. To understand what Kahneman means we must think of humans in the way that economists have for quite some time. When trying to model economies one must rely on abstractions and simplifications; if you don’t you’d have too many variables to make any conclusions. One of the simplifications economists had long made for humans was treating people as rational agents who maximize expected utility. From these simplifications we can build mighty edifices like supply and demand charts and correlations between employment and the speed by which money is moving through your economy. Yet Kahneman argues that these simplifications worked so well that they ended up hiding their own shortcomings. He then outlines some of the ways in which real human behavior diverges from what an economist would have predicted a perfectly rational agent would behave. These manifest in various cognitive biases that all humans have, from anchoring, which pulls estimates toward an arbitrary starting number, to loss aversion, which is how humans hate losing more than they like winning.
The final pair Kahneman describes is the experiencing self vs the remembering self. This section contains fascinating anecdotes highlighting the way that memory of experiences differs from the experiences themselves.
Odd as it may seem, I am my remembering self, and the experiencing self, who does my living, is like a stranger to me.
You may intuitively expect your brain to record experiences with a high fidelity, but it doesn’t. Repeatedly in experiments, people were asked to record their experiences in the moment, and then to record their remembered experiences. These two would, perhaps unsurprisingly, diverge, but the result would be that it was their memory of an experience that would inform their future choices, not the experience itself.
Thoughts
This is a quintessential popular science book. An absolute delight to read, and perhaps just a little too tidy. It has gotten criticism for relying on studies that haven’t been reproduced or with too small of sample size—Kahneman himself later admitted he put too much faith in underpowered priming work. Be that as it may, I like to view these types of books as checkpoints in a specialist’s understanding of the world. Don’t run too far with them, but they are bound to present you with new and useful ways of viewing the world. Kahneman delivers that in spades, even when some of the most memorable anecdotes (money priming individualism, smile/frown making you more gullible) turned out to be among the shakiest. The value of this book is that you start to see its descriptions everywhere, I would assume this is what Kahneman would call theory induced blindness.