Freakonomics | Steven D. Levitt and Stephen J. Dubner

I'm going to quote from the epilogue, because it precisely gives you my impression of the book:

"And now, with all these pages behind us, an early promise has been confirmed: this book indeed has no 'unifying theme.'

But if there is no unifying theme to Freakonomics, there is at least a common thread running through the everyday application of Freakonomics. It has to do with thinking sensibly about how people behave in the real world. All it requires is a novel way of looking, of discerning, of measuring. This isn't necessarily a difficult task, nor does it require supersophisticated thinking."

"Will the ability to think such thoughts improve your life materially? Probably not. Perhaps you'll put up a sturdy gate around your swimming pool or push your real-estate agent to work a little harder. But the net effect is likely to be more subtle than that. You might become more skeptical of the conventional wisdom..."

And the other thing that I think will give you a good understanding of the book, and maybe lead you to read it, is a list of the chapter headings:

1. What do Schoolteachers and Sumo Wrestlers Have in Common?

2. How is the Ku Klux Klan Like a Group of Real-Estate Agents?

3. Why Do Drug Dealers Still Live with Their Moms?

4. Where Have All the Criminals Gone?

5. What Makes a Perfect Parent?

6. Perfect Parenting Part II or Would a Roshanda by Any Other Name Smell as Sweet?

This book clearly exhibits people's laziness in society, when proving why certain things happen (in addition to a self-serving bias). Steven Levitt makes unpopular questions and statements in an effort to find the TRUTH in life. This is the closest to a theme that this work exhibits. However, be sure to take Levitt's advice to heart even as you read this: treat the information presented with a grain of salt. It's hard to take anything at face value, these days. Make sure to always ask the right questions, and seek the true answers.