Dobelli catalogues around 100 common cognitive biases and thinking errors — from confirmation bias to sunk cost fallacy — in short, two-to-three-page chapters, each with a clear real-world example, making it an easy reference to dip into rather than a book requiring cover-to-cover reading.
Key lessons
- Sunk cost fallacy leads people to keep investing in a failing decision purely because of what's already been spent.
- Confirmation bias means we notice and remember evidence that supports what we already believe, and overlook what contradicts it.
- Survivorship bias skews our sense of what works, because we only see the successes, not the much larger number of failures.
- Social proof and authority bias make us weight other people's choices and opinions more heavily than we should in our own decisions.
Most bad decisions follow a small, well-documented set of recurring thinking errors — being able to name and recognise them in the moment is the single most useful defence against them.
What’s aged well
The catalogue of biases draws on well-established behavioural science and remains a useful, evergreen reference.
What feels outdated
Nothing significant; short standalone chapters age individually rather than as a whole.
The Business Stuff verdict
A genuinely useful quick-reference for common thinking errors, best dipped into rather than read in one sitting.
Three things to actually do after reading it
- Identify one current business decision at risk of sunk cost fallacy, and evaluate it fresh, ignoring what's already spent.
- Actively seek out one piece of evidence that contradicts your current strategy, rather than only confirming evidence.
- Keep the book as a reference and check a live decision against the relevant bias before committing to it.
If you liked this, read next
Five similar books
- Thinking, Fast and Slow (Daniel Kahneman)
- Predictably Irrational (Dan Ariely)
- Nudge (Thaler & Sunstein)
- Superforecasting (Tetlock & Gardner)
- Noise (Kahneman, Sibony & Sunstein)
