This is a really interesting, surprisingly readable, explanation of how our unconscious mind possibly affects the decisions we actively and unknowingly make. The range of scope of these explanations spans from the minute to the grand, and is mostly backed with psychological research. The assumption that we as "rational" beings have 100% control over our choices is called into question, and if you're not narcissistic enough to believe that you understand all the aspects of the way your brain functions, you will be enlightened by the "hidden brain" explanation.

There's a smattering of good medical data provided, but the book is clearly accessible to everyone, and is a quick read. I'm not totally sold on all the connections that Vedantam makes, but the psychological testing is extremely interesting even if it raises unanswered questions.

If you've ever looked back on a decision you made and can honestly say to yourself "I have no idea why I did that", this book might begin to help you understand yourself a little more.