The book: Top Dog: The Science of Winning and Losing, by Po Bronson and Ashley Merryman.

The big idea: Nature and nurture combine to make us the competitive (or not-so-competitive) animals we are. By understanding what influences our perceptions of risk and ability to perform under pressure, we can make better decisions.

The backstory: Science journalists Bronson and Merryman previously teamed up on the best-selling NurtureShock, a book about child development research.

If you read nothing else: Are you wired to win or to not lose? The difference, explained in Chapter Seven, affects not only how you respond to setbacks but also how innovative you are. Chapter Eight reveals the dangers of ignoring things that almost went wrong but didn't.

Ladies' choice: The authors elegantly dismantle the women-are-less-competitive stereotype. Women fight just as hard as men--they just require better odds of winning before they will get in the game.

Finger check: Is your ring finger 10 percent to 20 percent longer than your index finger? If so, you probably possess such traits as assertiveness and risk tolerance that help entrepreneurs succeed. (It involves hormones and fetal development.)

Rigor rating: 9 (1=Who Moved My Cheese?; 10=Good to Great). The authors provide an exhaustive culling of medical literature as well as reader-friendly anecdotes drawn from business, sports, the arts, and the military.