A Modern Guide to Thinking, Fast and Slow

Daniel Kahneman’s Thinking, Fast and Slow has shaped how millions of people think about decision-making. It introduced a broad audience to cognitive biases and heuristics, and, perhaps most importantly, it encouraged readers to reflect on and question their own thinking.

Since the book’s publication in 2011, however, science has faced what’s now called the replication crisis. Across fields, many famous findings have failed to reproduce. Among them are some of the studies featured in Thinking, Fast and Slow.

Kahneman himself acknowledged this problem. In a 2012 letter to leading priming researchers, he wrote, “Your field is now the poster child for doubts about the integrity of psychological research.” He urged the community to confront doubts straight on, emphasizing the need for rigorous testing, transparency, and collective responsibility.

Thinking, Fast and Slow remains a valuable book on human judgment, but it should be read with an awareness that some of its most famous studies have not held up. I wrote this guide to help. It highlights which findings remain robust and which have failed to replicate. It is meant as a companion to read alongside the book.

1. Part I: Two Systems
2. Part II: Heuristics and Biases (coming soon)
3. Part III: Overconfidence (coming soon)
4. Part IV: Choices (coming soon)

Note: This project is ongoing, and I welcome corrections or suggestions for additions.