Men, women, and the joy of punishment.

Do men enjoy punishing evildoers? A study published last week in Nature suggests we do. Scientists planted actors among volunteers playing a game. Some actors played fairly; others played unfairly. Then the researchers delivered electric shocks to the actors while monitoring the brains of volunteers who looked on.

Men, like women, showed "empathy-related activation in pain-related brain areas" when shocks were administered to actors who had played fairly. But when shocks were delivered instead to actors who had played unfairly, empathetic responses in men, unlike women, "were significantly reduced." In fact, men showed "increased activation in reward-related areas, correlated with an expressed desire for revenge." Apparently, judgment controls men's feelings more than women's. It determines who gets our empathy and who gets our schadenfreude—the joy of watching the suffering of someone you dislike.

The study's authors say we need more evidence before asserting differences in empathy and schadenfreude between men and women. But we already have such evidence, in the form of polls about crime, war, and torture. All you have to do is look for gender differences, or lack thereof, on questions that touch various dimensions of the psychology of punishment.

Are men more vengeful? Yes. Five years ago, a Washington Post/ABC News survey  asked people whether they agreed or disagreed with a series of arguments for or against the death penalty. The biggest gender gap, by a factor of two, occurred over the argument that killers deserve death as "an eye for an eye." A plurality of women rejected this notion; two of every three men endorsed it. Princeton Survey Research Associates got similar results in a poll for Newsweek. Respondents were asked to name the main reason why they supported or opposed the death penalty. Among supporters, the reason that registered the biggest gender gap, albeit a small one, was "an eye for an eye."

But the Newsweek poll also illuminated the other side of the male mindset. As the electric-shock study implies, before a man can summon empathy or schadenfreude, he needs to know whether you're innocent or guilty. In the Newsweek survey, this proved true even among death-penalty opponents. When they were asked to pick the main reason for their position, the reason that registered the biggest gender gap by far was that "some innocent people being put to death." Thirty-five percent of the men picked that reason; only 21 percent of the women did.

Both aspects of male thinking were confirmed in a 2000 survey taken by Hart Research  for the Justice Project, an anti-death-penalty group. On executing murderers, male support exceeded female support by seven points. When respondents were offered the alternative of sending murderers to prison for life without parole, plus payment of restitution, nearly half the women who initially supported the death penalty abandoned it. But two-thirds of male death-penalty supporters clung to it, doubling the gender gap. Protecting the public wasn't enough; men wanted the killer killed.

Then the Hart poll sketched a bill that would require DNA testing in death-penalty cases but would do "nothing about the quality of court-appointed defense lawyers." Would such a law go too far, not far enough, or just the right distance? Sixty percent of women said it wouldn't go far enough; only 50 percent of men agreed. Men were less insistent than women on fairness, and more content to spare the provably innocent.

Are men more interested in violence? Yes. A 2002 Pew Research Center survey  asked Americans, "What should get a higher priority now: building our defenses at home to prevent future terrorist attacks, or taking military action to destroy terrorist networks around the world?" Women favored building defenses by a margin of 29 points; men favored it by just 8 points.

In the buildup to the Iraq war, men were less willing than women to string out diplomacy, and more willing to invade. Even among the war's supporters, an April 2003 Los Angeles Times survey found that reasons for doing so differed by gender. Women were more likely than men to say they wanted to stand behind President Bush, liberate the Iraqis, disarm Saddam Hussein, or remove a threat to America. Men were more likely than women to cite Saddam's violations of U.N. resolutions. The two reasons on which men overwhelmingly outscored women, by margins of more than three to one, were "retaliate for 9/11" and "finish 1991 Gulf War." Women focused on safety, loyalty, and compassion. Men focused on grudges, rules, and revenge.

Again, however, men's reactions hinged on distinguishing the guilty from the innocent. A Zogby poll  taken in March 2003, just before the invasion, illustrated the nuances. In a scenario with "thousands of American casualties," men were 10 points more likely to support war than to oppose it; women were 23 points more likely to oppose it than to support it. When the scenario was changed to "thousands of Iraqi civilian casualties," women's answers came out exactly the same, but men's margin of support shrank two points. If men were prone to empathy or schadenfreude purely on the basis of liking or disliking the suffering person, you'd expect them to support war more strongly, not less so, in the face of Iraqi rather than American casualties. But they didn't. The simplest explanation is that in men's minds—at least as strongly as in women's, according to the poll—the civilian character of the casualties outweighed the fact that they were foreign.