Enron, Worldcom, Bernie Madoff, the subprime mortgage crisis.

Over the past decade or so, news stories about unethical behavior have been a regular feature on TV, a long, discouraging parade of misdeeds marching across our screens. And in the face of these scandals, psychologists and economists have been slowly reworking how they think about the cause of unethical behavior.

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 In general, when we think about bad behavior, we think about it being tied to character: Bad people do bad things. But that model, researchers say, is profoundly inadequate.

Which brings us to the story of Toby Groves.

Chapter 1: The Promise

Toby grew up on a farm in Ohio. As a kid, the idea that he was a person of strong moral character was very important to him. Then one Sunday in 1986, when Toby was around 20, he went home for a visit with his family, and he had an experience that made the need to be good dramatically more pressing.

Twenty-two years after Toby made that promise to his father, he found himself standing in front of the exact same judge who had sentenced his brother, being sentenced for the exact same crime: fraud.

And not just any fraud — a massive bank fraud involving millions of dollars that drove several companies out of business and resulted in the loss of about a hundred jobs.

In 2008, Toby went to prison, where he says he spent two years staring at a ceiling, trying to understand what had happened.

Was he a bad character? Was it genetic? "Those were things that haunted me every second of every day," Toby says. "I just couldn't grasp it."

This very basic question — what causes unethical behavior? — has been getting a fair amount of attention from researchers recently, particularly those interested in how our brains process information when we make decisions.

Read More http://www.npr.org/2012/05/01/151764534/psychology-of-fraud-why-good-people-do-bad-things