I loved this book from the very beginning. Mr. Ariely writes in an engaging style, but what makes this book so valuable is how all the things he explores are explained clearly.
Where managers benefit from this book is in finding the logical, rational flaws in their own thinking as well as understanding how others think. When you understand your flaws, you can make better decisions - the strange part is how strange and counterintuitive it feels to make rational decisions sometimes. It just feels wrong.
You also can understand how other people are thinking. When you want to build relationships and help people grow, this understanding is critical.
I wouldn't say reading this book is critical to being a great manager, but it has been helpful beyond belief.
Rating: Highly Recommended