"The payoff for cheating, whether it's cheating on a college SAT test or cheating on your wife or cheating in athletic competition, is you'll win and get all the proceeds and accolades that go with the championship," Walsh said.

In the case of Armstrong, his alleged cheating began "as a little to win, and I don't think he envisioned seven Tours de France and millions of dollars of corporate sponsorship and America's reputation on the line in a worldwide stage," Walsh said.

"The problem with lies like that is that they have to build. They don't go away," she said. "The lies become bigger, bolder, more emphatic."

Why cheat in relationships?

Weinstein cited several reasons, more commonly afflicting long-term marriages or relationships.

"There's the thrill of being with somebody else. There's the thrill of participating in a taboo," Weinstein said. "If things aren't going well in your marriage, an affair may provide for needs that your marriage isn't."

The consequences of cheating in a marriage are considered by some as not as devastating as before, Walsh said.

"One of the reasons we're seeing so much marital infidelity, that version of cheating, is because the consequences have gone down. Divorce is not as expensive as it used to be, and women can support themselves now and there's far less social disgrace associated with it," said Walsh, author of "The 30-Day Love Detox."

But even for people with lots of money such as successful public figures, there can be a high cost elsewhere, such as in Tiger Woods' loss of corporate sponsors and his struggles as a player once his marital cheating was publicized, Weinstein said.

"You have to wonder is if there is a relationship between the scandal and his performance after the scandal," Weinstein said.

What's the answer to cheating?

It starts with leadership and setting standards, Wolpe said.

For example, he was working in Washington this week on a committee revising "Responsible Science," the bible on proper scientific conduct published by the National Academy of Sciences. The guide combats fraud, plagiarism and falsification in research and science, he said.

"Whether an institution or scientific enterprise, the expectation or models that they hold or they actually demonstrate in the way they live their lives are crucial," Wolpe said. "There's really a trickle-down theory in ethics."

The individual must take initiative too, Weinstein added.

"It's very difficult to live an ethically intelligent life," Weinstein said. "Keeping your word, keeping things private, telling the truth, avoiding hurting people, being fair and compassionate, all this takes work."