And because most of the faces we encounter are emotionally ambiguous, we’re forced into interpretations. …

“When you see someone just looking relatively neutral,” Munafo explains, “then it’s really down to you which of those interpretations you choose, and different groups of people see different things.” …

There they set up an intervention that attempted to retrain the way those kids interpreted faces. To begin, the kids were placed at computers and asked to identify the emotions in a series of faces that flashed on the screen. …

For a week, day after day, the kids looked at the faces again and again, relearning which faces were angry and which were happy.

Then the researchers tracked the number of aggressive incidents the kids were involved in. …

The kids who had been trained to visually see differently interacted with the world in a different way: They came at the world with less aggression.

“There was a 30 percent difference between the two groups,” Munafo says.