Does sex really persuade us to buy a product? Why do economies slip into depressions? And how much do we let our emotions influence our decision making? A spate of new books tries to answer these and other questions about how we make our choices, why they are sometimes so far off the mark and what their consequences are.

Animal Spirits—How Human Psychology Drives the Economy, and Why It Matters for Global Capitalism (Princeton University Press, 2009) examines the relation between economic fluctuations and psychological forces. Economists George Akerlof and Robert Shiller explore how “animal spirits”—the term coined by economist John Maynard Keynes to describe levels of consumer confidence—lie at the core of such questions as why there is unemployment and why minorities are often particularly poor.

In Management Rewired—Why Feedback Doesn’t Work and Other Surprising Lessons from the Latest Brain Science (Portfolio, 2009), business consultant Charles S. Jacobs reveals that, contrary to popular belief, decisions in the business world are never purely based on facts and logic. Looking at new research, the book also shows that rewards and punishments are not as effective as many managers think and that relying on pay raises and bonuses to improve performance is likely to backfire.

In Buyology—Truth and Lies about Why We Buy (Broadway, 2008), best-selling author Martin Lindstrom reveals the findings of the world’s largest neuromarketing study that examined the brains of 2,000 consumers. The book debunks myths about shoppers’ behavior by showing, for example, that dire health warnings on cigarette packs actually make us want to smoke more.

But how does our brain make those calls? In How We Decide (Houghton Mifflin, 2009), Scientific American Mind contributing editor Jonah Lehrer provides some answers to that question. Drawing from a wealth of recent neuroscience studies, Lehrer reveals what exactly is going on in our heads when we ponder whether to order chocolate, strawberry
or vanilla. Along the way he provides us with tools to make smarter decisions and shows us why it is important to have both gut instincts and rational thoughts participate in our decision-making process.

But in the end, why we buy what we buy comes down to our evolutionary history, explains psychologist Geoffrey Miller in Spent—Sex, Evolution, and Consumer Behavior (Viking, 2009). He argues that although we are not consciously aware of it, our product choices are rooted in our desire to advertise our personality and attract mates and friends.

Note: This article was originally printed with the title, "Reviews and Recommendations."