Like years past, this one has been a whopper for high-profile philanderers. Psychologists aren't surprised, as guys are wired to want sex, a lot, and are more likely than gals to cheat. The behavior may be particularly likely for men with power, researchers say, though they point out that despite the genetic propensity to sleep around, cheating remains a choice, not a DNA-bound destiny. The list of powerful individuals whose marital transgressions came out this year includes Tiger Woods, David Letterman, former senator John Edwards and South Carolina Gov. Mark Sanford. The obvious question, perhaps most perplexing when it comes...