At age 5, Charles Jacobs fretted that the world existed only in his mind. As a teenager, he fell hard for Freud. That lifelong fascination with human behavior has informed his work with the world's largest corporations, first at Amherst Consulting Group, which he founded in 1983 and sold in 1999, and more recently with 180 Partners. Editor-at-large Leigh Buchanan sat down with Jacobs to discuss his new book, Management Rewired: Why Feedback Doesn't Work and Other Surprising Lessons From the Latest Brain Science (Portfolio; May 2009).

Why teach business leaders about brain science?

Business executives are all about execution, facts. Trot out a psychological theory, and they don't want to hear about it. But they accept scientific data. Brain science gives us that hard data, which is the kind of information executives like.

Do business people put too much stock in logic?

Objective decision making is a myth. When the area of the brain responsible for logical thinking is activated, it also receives input from the area responsible for emotion. Without input from your feelings, you can't think long term. You don't learn from past experience; you can't empathize. The more complex the problem, the more of the brain should come into play.

Does Management Rewired mean changing minds involves physically changing brains?

The brain is very flexible. We have 100 billion neurons that connect to one another in 40 quadrillion ways. Thinking about something causes synapses between neurons to fire, creating a network. If I say, "Picture a seal balancing a ball on its nose," you've just built a neural network. Think about that seal over and over; the network is ingrained deeper. The synapse structure is changed. The threshold for firing at those synapses is lowered.

So there really is power in positive thinking.

Physical exercise develops different parts of your body; mental exercise develops parts of your mind. We are not victims of the neural networks we've inherited. A pessimist can train himself to be more optimistic.

You say the nucleus accumbens, which is responsible for pleasure, matures before the orbital frontal cortex, which handles long-term planning. Corporate executives sometimes do anything to meet quarterly targets. Entrepreneurs are all about sacrifice and delayed gratification. Does that mean entrepreneurs' orbital frontal cortexes are more mature?

Possibly. But it's also possible that entrepreneurs' nucleus accumbens are very active because they're so engaged in what they are doing. They get a big rush of reward from the work itself.

Would that influence the kind of decisions each makes?

If you are totally consumed by what you do, you begin to tell yourself a story: "This is who I am. This is my life." You've built this big neural network that drives decisions supportive of that. If, instead, you think logically -- this is just a job -- there's no context to drive decision making. So your decisions may go against what you really believe.

What does brain science tell us about leadership?

Recently, we've learned a lot about mirror neurons. If I observe you doing an action, the neurons in my brain responsible for that action will fire. So do neurons in the area that indicates intent. I'm not only mirroring your action in my brain; I'm also mirroring the reason for your action. The best thing a leader can do is set an example. Entrepreneurs are really jazzed by what they do. All they have to do is be who they are.

For an extended interview with Charles Jacobs, see www.inc.com/keyword/may09.