Thinking books · Decision making · Michael Lewis, 2016

The Undoing Project — the big ideas

The story of Kahneman and Tversky, and how the study of judgement errors came about.

Free — no account needed to read

The big ideas

It shows the research as it was made, which makes the findings easier to hold: each bias began as a specific puzzle about a specific wrong answer.

Undoing — how the mind constructs what almost happened — explains why some outcomes produce far more regret than equally bad ones, and why counterfactuals feel like analysis.

The collaboration itself is a model of productive disagreement between two people who thought very differently and checked each other constantly.

Practise it — no need to have read it

Take a bad outcome you still think about. Write the version where it almost did not happen. Notice how much of your regret attaches to that version rather than to the decision.

A hint: Near-misses feel like lessons and often are not.

Where it shows up in real life

• Processing a setback
• Post-mortems
• Understanding disproportionate regret

Described in our own words with the source named — never quoted, and not a substitute for reading the book.