Quite a few commentators on the Eliot Spitzer scandal are searching for some deep explanation for the frequent sex scandals involving powerful men. "Do you think men of power and success, men like Eliot Spitzer, get intoxicated with this kind of success?," asked Nightline's Terry Moran on Tuesday. "Are they reckless? Do they secretly want to get caught?" "Maybe it's the thrill, the rush of trying to get away with something. Maybe it's just arrogance," speculated the former wife of the former New Jersey governor in the New York Times.

It only takes a little bit of knowledge of how natural selection works to understand no such complicated explanations are necessary. In the evolutionary environment, men's best reproductive strategy was to have sex with as many fertile women as possible. (The incentives for women were different because of their ability to produce only one offspring per year). There were no doubt men who weren't interested in sex, or who wanted to have sex only with one woman, but they had fewer offspring and therefore failed, ultimately, to pass along their genes. The result: most men have a desire to have sex with multiple women. Men also tend to prefer younger women, because in the evolutionary environment (as now) youth is correlated with fertility. Rich and/or powerful men are no different in this respect from others, although it is easier for them to attract women. Monica Lewinsky probably wouldn't have been as interested in a middle-aged and married Bill Clinton if he were not the President, and 22 year-old Ashley Dupre certainly would not have been interested in having sex with 48-year old Eliot Spitzer if he hadn't been willing and able to shell out $4300.

That evolution provides an explanation doesn't mean it provides an excuse for selfish or socially irresponsible behavior, for Spitzer or for anyone else. The good news is that evolution has also equipped us with the ability to appreciate the consequences of our actions and exercise control over our instinctive drives. We should expect our elected officials obey the law, set a good example, and avoid putting themselves at risk of blackmail, even if they'd rather be sneaking off to the Mayflower Hotel. Invoking evolution in no way absolves Spitzer of responsibility for his actions. But if we want to understand what motivated Spitzer -- and before him the likes of Clinton, David Vitter, Gary Hart, John Kennedy, and list goes on -- to do something so risky, stupid, and potentially self-destructive, we need to recognize that drives honed by millions of years of natural selection are powerful and more difficult to resist than more ordinary types of preferences or desires. It is a safe bet that Spitzer would never in a million years consider shoplifting from a department store, even if he saw something he wanted and found he had left his credit cards at home.

To understand Spitzer's behavior, we really don't need an explanation any more sophisticated and nuanced than the one offered by former Hollywood madam Heidi Fleiss on Nightline. She responded to Terry Moran's absurd string of questions about Spitzer's possible psychological motivations by saying, "he wants to get laid."