After years on You Are Not So Smart cataloguing how badly human reasoning fails, this is the more useful follow-up, about what actually moves someone.
He reports on deep canvassing, where a conversation about lived experience shifts a position that argument never touches, and on street epistemology, which asks people how confident they are and why. He also spends time with people who left cults, conspiracy movements and Westboro Baptist.
The finding that stuck with me is that belief is social before it is factual. People do not drop a position because the evidence beat them. They move when changing their mind stops costing them standing in a group they care about.
I spent three years trying to align about 300 technology leaders across a federation where I had plenty of influence and almost no authority. Everything in this book matches what actually worked. Very little of it matches how change management usually gets written up.
I think it is the most practical book on persuasion I have read.