Thinking, Fast and Slow is a monster. It's a monster in length, in scope of content, and in general premise. But, it's also quite awesome and highly recommended.
So, why 4 stars? Well, as I said, it's really quite good but it really is a challenging read. In the same vein as many other books about behavioral economics, Kahneman's basic goal is trying to explain to the readers how we think. To do so, he narrows down our brain to two simplistic parts, simply titled: System 1 and System 2. System 1 moves fast, very fast, instinctual fast. System 2 is slow, analyzing everything. System 1 does a vast majority of our everyday lives: read, breath, eat, walk, drive, etc. System 2 does the more complex stuff, but it asked to take things on far less often. The problem in life is that many things that we should be using System 2 for, System 1 takes on (silly System 1), and vice versa. So, basically the book is trying to explain and rectify these issues.
Overall, the book is fascinating. While I had seen many of the studies from it in other books on behavioral econ., like Predictably Irrational or Nudge, I still love the premise of this book, and though he gets way too deep on some things, the basic points of each chapters and large sections are fantastic. He has a great organization to the book and there is pretty good flow during his presentations from experiment to the other. It's really amazing how much though has gone in to understanding our thoughts and this, at least to me, is the most comprehensively explained books of this type.
The biggest drawback, however, and what kept it from a higher rating, was the length and difficulty to follow some of his writing. To me, Malcolm Gladwell, is one the best at simplifying complex ideas and taking rather scientific studies and making them clear to a laymen like myself. Kahneman, while nowhere near as difficult to follow as, say a scientific journal, does not have Gladwell's skills for being straightforward and clear. While one might think this is not a big deal, I agree it's not, until you ask someone to read over 500 pages and, by the end, they are begging for a better editor. So, yeah, it's kind of a rough read throughout many spots.
Overall, though, this book really is a gem. So many great experiments, so many wonderful points made, so many new ideas and concepts for the reader to think on, and so many interesting ways to better look at, and contemplate, human psychology. While you need to have a specific interest in this type of work to read this book, if you do have some time and can manage to wade through the deep end of the some these ideas, you will come out on the other side with a much better understanding of thinking.