Book Summary
Published by Viking on February 2, 2021, Think Again carries the subtitle The Power of Knowing What You Don’t Know, and it became a number one New York Times bestseller on the strength of a simple idea: the smartest people are not the ones who are right most often, but the ones who change their minds most readily when the evidence changes. Grant, an organizational psychologist at Wharton, argues that rethinking — the ability to question your own opinions and open other people’s minds — is a skill, and that most of us are bad at it for reasons we can fix.
The book’s central image is a set of mental modes. When we argue, Grant says, we tend to slip into the modes of a preacher, defending our beliefs; a prosecutor, attacking the other side’s; or a politician, campaigning for approval. The mode we need instead is the scientist: treating our beliefs as hypotheses, looking for reasons we might be wrong, and revising when the data says so. The rest of the book is a tour of how to do that — in our own thinking, in our relationships, and in our workplaces — with research and stories from scientists, negotiators, and even a group of firefighters who survived by rethinking their training in the moment.
What makes the book work is Grant’s tone. He is a researcher writing for a general reader, and the book reads like a series of experiments you can run on yourself: argue like you are right but listen like you are wrong, seek out the people who disagree with you, and treat changing your mind as a sign of learning rather than weakness. For an investor, the lesson lands directly — markets punish the inability to update — and the book pairs naturally with {IL(U[‘thinking-bets’], ‘Thinking in Bets’)} for decision-making under uncertainty, and with {IL(U[‘thinking-fast-slow’], ‘Thinking, Fast and Slow’)} for the psychology underneath it.
Who is Adam Grant?
Adam Grant is an organizational psychologist at the Wharton School of the University of Pennsylvania, where he has been the top-rated professor, and the bestselling author of Give and Take, Originals, and Hidden Potential in addition to this book. His work sits at the intersection of psychology and work: how people think, how they decide, and how organizations can be built to make better use of both. His books are known for the same combination — rigorous research presented through stories — and Think Again is the most personal of them, a book about changing his own mind as much as anyone else’s.
Grant’s influence comes from his ability to make research usable. He hosts a popular podcast, writes for the New York Times, and is one of the most cited voices on how people and teams actually work. Think Again grew out of his own experience of being wrong in public — about ideas, about people, about his own field — and the book’s argument is one he had to learn himself: that the willingness to rethink is not a flaw in a thinker but the thing that makes a thinker good.
Lessons From Think Again
Think like a scientist, not like a preacher, prosecutor, or politician. The book’s first lesson is to notice which mode you are in when you argue. The preacher defends, the prosecutor attacks, the politician campaigns — and none of them learns anything. The scientist treats a belief as a hypothesis and looks for the evidence that would disprove it. The difference is not intelligence but posture, and posture can be practiced.
Confident humility beats both arrogance and doubt. Grant’s phrase for the ideal stance is confident humility: faith in your ability to learn combined with doubt about what you currently know. Arrogance stops you from updating; self-doubt stops you from acting. Confident humility lets you hold a view firmly while staying open to the evidence that it is wrong — which is exactly the stance an investor needs when a position starts to go against them.
Seek out the people who disagree with you. The book’s most practical advice is to build a challenge network — people who will tell you when you are wrong, and whom you trust enough to listen to. We naturally surround ourselves with people who confirm our views, and the result is that our blind spots go unexamined for years. The fix is deliberate: find the critics, ask them what you are missing, and treat their disagreement as data rather than an attack.
Changing your mind is learning, not failing. Grant argues that we treat consistency as a virtue and flip-flopping as a vice, when the evidence says the opposite: the people who update their views as new information arrives make better decisions than the people who hold firm. The book’s closing idea is that the joy of being wrong — the feeling of discovering you were mistaken and now know more — is one of the best feelings thinking has to offer, and it is available to anyone willing to practice it.
Criticisms of the Book
The main weakness of Think Again is that it is better at describing rethinking than at guaranteeing it. Grant is honest that changing minds — especially other people’s — is hard, and some readers will find the book’s advice easier to admire than to apply. The research is strong, but the leap from laboratory findings to everyday arguments is a long one, and the book sometimes makes that leap more smoothly than real life allows. Readers who want the harder-edged version of decision-making under uncertainty should pair it with Thinking in Bets.
The book is also, by design, about thinking rather than about money. Its lessons bear directly on financial decisions — an investor who cannot update is an investor who holds losers too long — but the book itself rarely talks about investing. For the psychology of money specifically, The Psychology of Money is the more direct companion, and for the biases that make rethinking hard in the first place, Thinking, Fast and Slow and The Little Book of Behavioral Investing are the deeper treatments.
Who is This Book For?
This is the book for anyone whose job involves being right under uncertainty — an investor, a manager, a founder, a parent, a voter — and who has noticed that holding firm feels good and works badly. It pairs naturally with Thinking in Bets for the decision-making half of the problem, and with The Art of Choosing for how we actually make choices when the options are unclear. Readers who enjoyed either will find this one the most hopeful of the three — a book that believes people can change their minds, including yours.
It is less useful for readers who want a finance book. The lessons about updating, humility, and challenge networks travel well to investing, but the book is about thinking in general, and a reader who wants portfolio construction or valuation methods will find more directly applicable material in the investing books on this site.
Final Thoughts
Think Again has lasted because it names something everyone has experienced and few have a word for: the moment you realize you were wrong, and the strange relief that comes with it. Grant’s argument — that rethinking is a skill, that confident humility is the stance to practice, and that changing your mind is learning rather than failing — is simple to state and hard to live, which is why readers keep returning to the book long after they have finished it.
Read it before your next big decision, and read it again the next time you catch yourself defending a position you no longer believe — the second time through, the chapters on the scientist mode read less like psychology and more like a description of your own last argument. As an introduction to the art of changing your mind, it remains one of the most useful books on the subject.
