When children see others in pain, their brains respond as if it were happening to them, U.S. researchers said on Friday.

This response, which also has been shown in adults, suggests that normal school-age children may be naturally prone to empathy, they said.

"What it shows us is that we have this inborn capacity to resonate with the pain of others. That's probably a very important step toward empathy," said Jean Decety of the University of Chicago, whose study appears in the journal Neuropsychologia.

For the study, the researchers showed 17 children aged 7 to 12 animated images of people experiencing pain while they were undergoing a type of imaging known as functional magnetic resonance imaging or fMRI.

The series of images depicted accidents, such as a heavy bowl falling on a pair of hands, and situations in which pain was inflicted on purpose, such as someone slamming a car door on a person's hand. They also were shown images without painful encounters.

The study showed that when pain was accidental, brain circuits involved in the processing pain first-hand came into play.

Decety said these same areas have been shown to become active in studies in adults and are thought to be part of the empathy response.

"We can say children are like adults when they see people in pain," Decety said in a telephone interview.

But when the pain was intentionally inflicted, areas involved in social functioning and moral behavior also came into play.

These areas are involved in assessing threats, he said.

"The children were looking for a reason," Decety said. "If you watch someone being hurt, you want to know why."

Decety said many of the children asked whether the situation had been fair.

"If you think about looking for a reason, this is more like caring for others," he said.

Decety said he hopes to use these results to better understand brain function in children who are aggressive or engage in anti-social behavior, such as bullying.