A review by erikars
How We Decide by Jonah Lehrer

4.0

Not surprisingly, How We Decide has a fair amount of overlap with other popular books about the mind including some that I have read ([b:Blink|2142|Blink|Ted Dekker|http://d.gr-assets.com/books/1160527104s/2142.jpg|54935], [b:The Time Paradox|2179276|The Time Paradox (Artemis Fowl, #6)|Eoin Colfer|http://d.gr-assets.com/books/1348831630s/2179276.jpg|2184954], and [b:The Paradox of Choice|10639|The Paradox of Choice Why More Is Less|Barry Schwartz|http://d.gr-assets.com/books/1348386990s/10639.jpg|1157840]). However, despite an overlap in subject matter and in the studies cited, I feel like this book is among the better of these types of books.

In addition to presenting conclusions based on psychological studies, Lehrer uses information we have gained from studying the brain to build a description of how decision making works. The main tension when making decisions is between the emotional brain and the rational brain. Actually, that is a simplification. Both systems consist of multiple systems which may, in turn, disagree with each other. On the other side of the coin, both the emotional brain are really part of the same system and influence each other. But as a mental model, this two part view of the brain is instructive.

The details are interesting, but in the hopes of keeping things concise, I will cut to the chase. The emotional brain is good at taking in a lot of information and matching it against past experience. It's good for deciding personal preferences or making decisions in areas where you have a lot of experience. The rational brain is good at dealing with new experiences but can only take in a small amount of information. It's good at creating new solutions or making decisions when there are only a small number of factors to consider (perhaps as little as a dozen total across the possibilities).

When they work well, these two systems help each other, with the emotional brain internalizing when decisions in certain contexts lead to good and bad outcomes and the rational brain deciding when something new needs to be tried. When either of these systems fails completely (as happens with some types of brain trauma), people become unable to function independently Those who lose rational brain functionality become unable to make considered decisions. Those who lose emotional brain functionality become unable to make decisions at all.

Lehrer states in his conclusion that the most important thing you should take from this book is that you should think about thinking. This allows you to avoid stupid errors that arise from predictable brain errors (errors such as loss aversion). It also allows you to improve the working of your brain over time.

Another key thing to take from How We Decide is the idea that certainty is self defeating if you want to use your brain effectively. Certainty quiets the internal dissent that your various brain parts generate and leads to bad decisions. As Lehrer says:
The only way to counteract the bias for certainty is to encourage some inner dissonance. We must force ourselves to think about the information we don't want to think about, to pay attention to the data that disturbs our entrenched beliefs. We we start censoring our minds, turning of those brain areas that contradict our assumptions, we end up ignoring relevant evidence. ...

But the certainty trap is not inevitable. We can take steps to prevent ourselves from shutting down our minds' argument too soon. We can consciously correct for this innate tendency. And if those steps fail, we can create decision-making environments that help us better entertain competing hypotheses. ...

when making decisions, actively resist the urge to suppress the argument. Instead, take time to listen to what all the different brain areas have to say. Good decisions rarely emerge from a false consensus.


So spend some time thinking about thinking.