Despite the headlines — the incessant reports of roadside bombs and gang killings and civil wars — humans are actually becoming less violent.

That's the encouraging news from a national conference this week at the University of Utah.

The conference, "The Evolution of Human Aggression: Lessons for Today's Conflicts," is presented by the university's Barbara L. and Norman C. Tanner Center for Nonviolent Human Rights Advocacy. Over three days, the conference has explored aggression among chimps, homicide rates among humans, and domestic violence.

The upshot: violence may be part of our nature, but so are cooperation and reconciliation, traits we may have inherited from our primate ancestors. Over the course of history, there is evidence that we're figuring out how to get along better, or at least recognizing that it's to our benefit not to whack each other's heads off.

"Contrary to popular belief, our ancestors were far more violent" than we are, said Harvard University psychology professor Steven Pinker. And today is "probably the most peaceful time in history."

Despite the fact that a third of men and 15 percent of women report having fantasies of killing someone they don't like, as individuals and societies we're better able to inhibit those violent tendencies, Pinker said.

From war deaths to capital punishment to sadistic entertainment (in 16th-century Paris, people enjoyed watching cats burned alive), violence has decreased over time. Since the Cold War, he says, there has been a sharp reduction in genocides, and since 2000 there have been fewer war deaths, including civil wars.

Instead of asking "why is there war?" he said, it might be better to study why there is peace.

That's what primate researcher Frans de Waal of Emory University has been asking for several decades, researching how chimps, monkeys and bonobos make up after a fight. (Actually, the only species that lacks a desire to reconcile is the domestic cat, says de Waal, perhaps because they haven't figured out why they need other cats.)

In one experiment, rhesus monkeys (considered among the most aggressive primates and the least likely to reconcile) were put in living situations with peaceable stumptails, who "tutored" them in the art of peacemaking. The rhesus monkeys' ability to learn peace "shows we can change behavior by changing the social environment," de Waal said.

Large-scale modern human warfare in which soldiers are sent off to fight an enemy is not based on aggression but on "political decision-making." And that's something, he added, that we have control over.