What makes politicians stray?

Last week, Arnold Schwarzenegger joined the club of leading male political figures who are known to have cheated on their spouses. Other members have included presidents (John F. Kennedy, Bill Clinton and Franklin D. Roosevelt, for example), members or former members of Congress (among them, John Edwards, Newt Gingrich and John Ensign), and governors (including Eliot Spitzer and Mark Sanford).

So why do we keep electing such people? And why, in many cases, do we continue to see the philanderers as heroes? For one thing, some of the very personality characteristics that make a person suited to politics — features people tend to admire — are also ones that may predispose a person to infidelity.

Gingrich, who while still married to his second wife had an affair with the woman who would become his third wife, recently explained his actions this way: “There’s no question at times of my life, partially driven by how passionately I felt about this country, that I worked far too hard and things happened in my life that were not appropriate.�

His statement is an insult to millions of hardworking, monogamous Americans. But if passion for one’s country and hard work aren’t what predispose politicians to infidelity, then what does?

There are many possible factors: a need to express power, a love of conquest, perhaps narcissism — all characteristics that may serve a politician well in other arenas. But in my view the factor most responsible for philandering in public officials is a predisposition for risk-taking, which also happens to be an essential quality for politicians. My label for it is the “Type T personality,� with the “T� standing for thrill.

Being a Type T doesn’t have to be a problem: Many of America’s great successes and achievements couldn’t have happened without risk-takers. The nation was founded by Type T men who weren’t afraid to rise up against one of the world’s great empires. I believe the United States can be characterized to some extent as a Type T nation, tilting in the risk-taking direction. But Type T individuals may also be prone to negative types of risk-taking, including crime, drug use or sexual encounters that end badly.

Risk-takers want to live exciting, interesting, challenging lives. They tend to believe they control their fates. They are often attracted to variety, novelty, intensity and uncertainty. They are often creative, show independence of judgment and tend to have strong sexual drives and high energy.

In politics, we tend not to vote for wallflowers. We like charisma, boldness and new ideas emphatically stated. This is part of the reason Type T politicians so frequently win the day. But once in office, they may also display less desirable risk-taking behavior. It’s in their personalities.

Why might we expect risk-takers to be attracted to leadership roles in politics? Analyze the job. It’s unpredictable. A candidate can pour everything he or she has into a campaign and still lose. There is no tenure, no 9-to-5 schedule, and constant travel. A politician always has to be on, and be comfortable meeting a constant stream of new people and speaking extemporaneously in public. There is no proven playbook for success. A politician also lives a fishbowl life, with little privacy. Every day, there are decisions to be made that can make or break a career. Maintaining a normal home, family and marital life is nearly impossible. Who can not only accept but thrive in such circumstances? Risk-takers.

Another factor in the frequent infidelities of politicians is the fact that they are often surrounded by acolytes — adoring followers, campaign workers, office staff — all focused on pleasing the politician. That adoration can stand in stark contrast to, say, a wife back home who resents that she’s now the only one to take out the garbage, walk the dog and ferry the kids to soccer practice.

So far, political sex scandals have overwhelmingly involved male politicians, in part because they still make up the bulk of elected officials. But as the proportion of female political figures increases, it’s likely that the gender infidelity gap will narrow. After all, female politicians need to be risk-takers too.

One thing I find particularly interesting is how willing Americans are over time to forgive the cheating behavior of Type Ts as long as there was no crime or coercion, and as long as the betrayal wasn’t particularly heinous (as in, say, when there is a seriously ill spouse in the picture). In general, we don’t let sexual misbehavior color our view of an official’s political legacy.

But even though we tend to eventually forgive our politicians their sexual misadventures, they rarely run again once their infidelities have become widely known. This means we have little data on whether the public’s willingness to forgive extends to the ballot box. We who study such things need many more examples of known cheaters who try again to run for office before we can draw valid conclusions as to the electorate’s actual vote on such misbehavior. I have a feeling we’ll get them.

Frank Farley is a psychologist and professor at Temple University. He is former president of the American Psychological Assn.