What would possess a smart, wealthy, successful business executive to lie and steal money they don't really need from people who do?
If you said greed, you only have part of the equation according to Terry Leap, a University of Tennessee-Knoxville management professor who has spent some three decades studying deviant behavior in business.
The other factor frequently found in some of the most egregious frauds: "narcissistic personality disorder," or that close cousin of greed: ego.
"Narcissistic people have a high sense of entitlement and an abundance of egocentric, 'the world revolves around me,' and egotistical, 'I'm better than anyone else' behaviors," Leap told CNBC. "They are shameless self-promoters who are arrogant, haughty, and oblivious to the harm they cause others."
Leap says a hallmark of narcissistic personality disorder is what he calls "a strong sense of entitlement."
"When they see something they like and want, such as the hard-earned money of fund investors, … they believe they are entitled to take it, regardless of the damage they cause."
In the annals of modern-day white-collar crime, few people have had a more powerful combination of greed and ego than Sky Capital founder Ross Mandell.
Even after his 2009 indictment for running a $140 million investment scam, Mandell refused to be humbled.
"Conventional wisdom for people in my situation is to lay low, get small, lawyer up," he said at the time.