Editor's note: Frank Farley is a professor at Temple University and a former president of the American Psychological Association.
(CNN) -- Human behavior can be mysterious, and one big mystery is why successful, smart politicians commit adultery or near-pornographic stunts despite the constant presence of the eyes and ears of the public.
Given the number of politicans who have been caught in such behavior of late, one might be forgiven in thinking it's an epidemic.
U.S. Rep. Anthony Weiner, a New York Democrat headed for the top with large ambitions, tweets a photo of his occupied underpants to a young woman, and apparently tweets or "sexts" risqué comments and photos to other women.
One problem is he's married. What of those marriage vows about love and honor, especially honor? Another: Married or not, why would you ever take such a photo and send it to anyone, particularly if you are a public servant?
This behavior reinforces the view that politicians are screwed-up or stupid or out-of-touch. Sometimes we "throw the bums out," or they leave on their own. But often, they remain in the picture in one way or another, despite their perfidy or peccadilloes.
Bill Clinton left office with relatively high approval ratings and became a beloved former president and sought-after international leader and adviser. We know of FDR's mistress, JFK's many indiscretions and even MLK Jr.'s adultery. But that has not deterred Americans from often ranking them as heroes.
In demystifying these politicians' behavior, you find there are multiple causes: Very few complex human behaviors are caused by just one attribute. And the causes can vary somewhat from politician to politician.
I think a good way to approach the issue is to look at what kind of person would be attracted to the politician's job and do well in it?
Here are some key features of the political life: high uncertainty and unpredictability, no significant job security and no playbook that guarantees success.
You can be voted out and not know clearly why. You can say something or make a decision and lose the voters' support and your job. You have no 9-to-5 day or normal home and family life. You do have a fishbowl existence. You often must speak in public or to the media extemporaneously, travel extensively, meet new people all the time and you often encounter fans who offer opportunities for transgressions. A risk-taking personality would be attracted to many of those features. I call it the "Type T," for thrill-seeker personality.
It describes someone who is motivated by the thrill, excitement or stimulation of risk. It's a rush for them. For most politicians, the risk and thrill are basically psychological, and it happens in public speaking, media interviews and social life. But that thrill can also involve the physical, the kind encountered in travel and sex.
Novelty, variety, intense experiences, an emphasis on individual and independent judgment; a belief that you control your destiny; innovation, challenge and high energy are all factors. Apply these personal qualities to the demands of the political life, and it's a perfect fit.
So if a Type-T personality is a significant ingredient in the political life, interesting possibilities are raised.
We value the positive side of risk-taking, which can make a bold, active, change-oriented leader. But sometimes that hard-wired risk-taking can take a negative or destructive form, particularly given the relentless opportunities for cheating in the political life.
The deep self-confidence needed for risk-taking sometimes means the risk-taker refuses to acknowledge or see the possibility of getting caught, despite the fishbowl reality.
There is a storied history to the Type-T behavior in American politics. Some of our founding fathers exemplified it, Ben Franklin leading the way. It won't disappear.
Our history as a nation has tilted in the risk-taking direction. Given the openness and freedoms of a great democracy, boundaries of behavior will remain blurred and some risk-taking pols will always cross them.
The opinions expressed in this commentary are solely those of Frank Farley.