Children as young as 3 years old will intervene on behalf of a victim, reacting as if victimized themselves, scientists have found.

With toys, cookies and puppets, Keith Jensen, a psychologist at the University of Manchester in England, and his colleagues tried to judge how much concern 3- and 5-year-olds had for others, and whether they had a sense of so-called restorative justice.

In one experiment, when one puppet took toys or cookies from another puppet, children responded by pulling a string that locked the objects in an inaccessible cave.

When puppets took objects directly from the children themselves, they responded in the same way.

“The children treated these two violations equally,” said Jensen, a co-author of the study published in the journal Current Biology.

In another experiment, when an object was lost or stolen, children tried to right the wrong by returning the object to the puppet it belonged to.

“Their sense of justice is victim-focused rather than perpetrator focused,” Jensen said. “The take-home message is that preschool children are sensitive to harm to others, and given a choice would rather restore things to help the victim than punish the perpetrator.”