In one recent study, researchers led by Adam Galinsky of Northwestern University primed participants to feel powerful by having them write about an incident in which they had control over others and then distribute lottery tickets to themselves and another study subject. These “high-powered” people were significantly less accurate in reading emotions from facial photographs than a comparison group of participants who were not primed in the same way. This and other experiments suggest that power can blind people to the emotions of those around them and lead to “objectifying others in a self-interested way,” the authors concluded.

“If the person has this sense of superiority, and they’ve gotten away with these kinds of things before, they begin to think that the risk-reward ratio that applies to everyone else doesn’t apply to them because they’re so special,” said Samuel Barondes, a professor of psychiatry at the University of California, San Francisco, and author of the forthcoming, “Making Sense of People.” “It’s hard for people who don’t think that way about themselves to believe that anyone else really does. But they do.”

The exception may be the sort of man who is so consumed with advancement that certain personality traits go unexamined or unexpressed along the way. Feelings of inadequacy, a longing for paths not taken, or a sense of gratification too long delayed can prompt the taking of one small risk, one awkward advance, and then another, therapists say. It’s easy to ridicule such motives, and they do not justify the harm done to others when the chairman reaches for the cookie jar, or the thigh of a Congressional page. But they are motives nonetheless — for sexual transgressions, if only rarely sexual deviance.

And once the cheating or the groping starts, “there’s really no telling where it ends, if the person has real power and begins to believe they can continue to get away with it,” said William B. Helmreich, a sociologist at City College of New York and author of “What Was I Thinking: The Dumb Things We Do and How to Avoid Them.”

That is, if it starts at all. In a survey of young men, Dr. Levant found that attitudes toward sex were far less defined by locker-room culture than commonly assumed. Responses varied widely but on average the participants agreed that a man “should love his sex partner,” that he should “have to worry about birth control,” and that he shouldn’t “always have to take the initiative when it comes to sex.”

These and other, similar findings seem only mildly surprising, until placed in a larger context. For most of human history, men have treated women much as they pleased, and powerful men routinely collected wives and lovers, feeling free to maim or kill those who offended. The social norms, criminal laws and progressive culture of the West evolved in part to check such abuses, and most men not only observe those rules but also, as the attitude surveys show, internalize them.

Mr. Schwarzenegger, who issued a public apology, is now familiar with the sting that violating such shared social rules can deliver. Mr. Strauss-Kahn, who is alleged to have committed a far more serious act, will suffer more than public embarrassment. He might face a jury of his peers.