BackStartups

Book · How to decide

Thinking, Fast and Slow

Daniel Kahneman · 2011

The foundational account of how human judgement systematically fails, by the psychologist who did more than anyone to demonstrate it.

Why it is here

Angel investing consists of repeated judgements made under deep uncertainty with feedback arriving years later. That is very close to the worst possible environment for human intuition, and this is the book that explains precisely how and why it goes wrong.

The directly applicable material: the substitution of an easy question for a hard one — "do I like these founders" for "will this company be worth a hundred times what I am paying"; overconfidence in small samples; the way vivid stories overwhelm base rates. Every one of those is a described failure mode of angel investing.

Some of the specific studies it reports have been contested in the years since. The core account of how judgement fails has survived that scrutiny, and the parts most relevant to investing are among the better-supported.

Read it if

You want to understand the mechanism behind the mistakes you will make repeatedly.

Skip it if

You want prescriptions. It is exceptionally good at diagnosis and deliberately modest about cures.

Pair it withSuperforecastingPhilip Tetlock & Dan GardnerWhat research on forecasting tournaments found about who predicts well, and the habits that turn out to distinguish them.

Thinking, Fast and Slow: common questions

Which bias matters most in angel investing?
Attribute substitution — answering an easier question than the one asked. "Do I like and trust these founders" is answerable in an hour; "will this be worth a hundred times what I am paying" is not, and the first quietly stands in for the second.
Has the replication crisis undermined this book?
Some specific studies it cites have been contested, and the author acknowledged as much regarding parts of it. The central account of how judgement fails under uncertainty is well supported, and the sections most relevant to investing are among the sturdier ones.