AMRISHA VAISH: There's no doubt that being social, being cooperative, being what some people have called ultra co-operative is in many ways our superpower. When those relationships are ruptured in some way, due perhaps to one person causing harm to another, it's really important that we are able to repair those relationships. Forgiveness is a really critical part of that repair.

NARRATOR: Social ties are the basis of every community on Earth. But those relationships are also fragile. So how do we repair them when they're strained or broken? Philosophy and religion have espoused the virtues of forgiveness for millennia, but the scientific study of forgiveness is fairly new.

VAISH: My name is Amrisha Vaish, and I study how children behave cooperatively towards others and learn to be moral individuals. Causing harm, apologizing, showing remorse, feeling concerned for someone who's been harmed, all of those are things that children pay attention to very, very early on. Really in the first year already. And I think that tells us something about who we are as a species.

NARRATOR: Amrisha's research involves observing different interactions between a transgressor, someone who does something hurtful, and a victim, the person hurt by the transgressor. By observing these interactions, she has been able to see what actually matters to children when they choose their friends and collaborators. And how we as adults could re-examine our priorities when it comes to maintaining these social ties. In one study, two experimenters and one child all drew pictures. Then, the experimenters ripped the child's drawing.

VAISH: And one of the transgressors now shows remorse to the child. So she says, "Oh, I've torn your picture. I didn't mean to do that. It's my fault." And the other transgressor is neutral. So she says, "Oh, I've torn your picture. Oh, well." And so what we now do is ask whom they prefer. Then what we found is that by five years of age, children clearly preferred the one who had shown remorse.

NARRATOR: By apologizing to the child, the transgressor demonstrated a commitment to maintaining their positive relationship. That made the child want to maintain it too. But in real life, our interactions always have more background context, such as where we grew up, where we went to school, and what social groups we align ourselves with. So how do our group identities affect our ability to choose who we associate with?

VAISH: In a more recent study, we placed children in a group, either a yellow group or a green group. And then the two experimenters who came in, one of them was in the same group as the child, and the second experimenter was the out-group member. And so we had now, the same thing, everyone drew a picture and both individuals accidentally tore the child's picture. And this time both of them showed remorse. And what we found is that even though both of them had shown remorse, children very clearly preferred the in-group individual.

NARRATOR: By the age of five, children have already developed biases for their group, their community. But do children just prefer their own group, no matter how they treat them?

VAISH: And so to follow up on this, we had the same setup, but now the in-group member did not show remorse, but the out-group member did show remorse. And so even though she's in the out-group she's showing this kind of commitment to the child.

NARRATOR: Amrisha's team found that children consistently prefer the transgressor who showed remorse in this scenario, in spite of their different group identity.

VAISH: And so here we see what they really care about is that the transgressor shows their commitment to them, to the relationship. And they will seek that person out over even an in-group member.

NARRATOR: When we apologize to someone outside of our group, we signal to them that we recognize their humanity and that we want to treat them well, regardless of what group they're in. We're also acknowledging that a relationship with them could be valuable to us, and being in different groups doesn't have to define how we interact. And when we forgive an individual from another group, we're allowing them to try and bridge that gap too. The more often we can practice these skills, the greater chance we have of building trust and relationships between groups that may seem vastly different.

VAISH: We humans are such a super social species. We really rely on each other to succeed, to achieve what we want to achieve both as individuals and as a community. To do that, it's really vital that we maintain and sustain our cooperative relationships. We wouldn't survive without them. Absolutely.

NARRATOR: To learn more about challenging ideas like this, visit us at templeton.org/big questions.