“That’s my red train!” Emma yells at her twin sister.

“No it’s not! It’s mine!” shrieks Olivia.

The little lookalikes explode in anger — biting, scratching, and slinging toddler epithets as they battle for sole possession of the crimson locomotive.

“Stop, please,” you beg, wondering how did they share my womb for nine months?

While watching toddlers fight over a toy can make it seem like their natural state is every-kid-for-herself, anthropologists say generosity is a deeply ingrained human behavior. Helping others promotes the survival of our species. Young children’s understanding of the nuances of generosity is complex, but encouraging altruistic behavior doesn’t have to be. Try working these simple tips into your daily routine to cultivate your child’s generosity.

  1. Share and show it

    Even very young children pick up on the generous behavior of those around them. Research shows a parent’s generous acts influence the child to be similarly giving. While other studies have discounted the impact of role modeling in getting kids to be generous, Mark Ottoni-Wilhelm, professor of philanthropic studies at the Indiana University Lilly Family School of Philanthropy and lead author of a study on the intergenerational transmission of generosity, has a theory about this. “It may be that kids do not see their parents role modeling generosity,” he says. He has become more open about his own generous acts, he says, so that his kids learn to behave likewise. “My kids knew my wife and I gave, but they had little idea to what and to what extent. So I started talking about it a little more.” The takeaway? Model generosity and don’t hide it — make it a part of your family’s culture.

  2. Take turns

    A recent series of Stanford University studies found that simple reciprocal activities triggered altruistic behavior in children as young as 1 and 2. In other words, you can plant the seeds of generosity in your child by taking turns rolling a ball, pushing buttons on a small musical toy, or handing objects back and forth to each other. The results suggest that kids are socialized to behave generously, and that taking turns fosters both the act of giving and the expectation of such behavior from others. “After an experience with reciprocity, children seem to construct a community characterized by care and commitment,” the researchers wrote. “Experimenters, parents, teachers, and others who regularly interact reciprocally with children may be implicitly communicating to children that in these contexts, people help one another.”

  3. Serve meals family-style

    A plate of perfect pancakes comes to the table, accompanied by syrup, blueberries, and whipped cream. Instead of doling them out evenly, try guiding your kids to help themselves. A 2015 Belgian study found that young adults who had experienced more family-style meals (where diners help themselves to portions from a communal dish while being mindful of how much is left for the other people at the table) in childhood scored higher on tests of altruism. “Sharing meals has the power to train children to become fair-minded,” conclude the study’s authors, because it creates regular situations where diners are confronted with issues of fairness and respect. The takeaway? Spare yourself the cries of “His slice is bigger!” and let the kids practice serving themselves.

  4. Be careful of comparisons

    From babyhood, humans are attracted to kind individuals. But recent research suggests that there are contexts in which generosity can provoke aversion and resentment, particularly if one child is held up as an example to other kids whose behavior is less generous. A 2015 study of 8- to 10-year-olds showed that when adults praise one child’s generous behavior at the expense of another’s, the generous child will be disliked by his peers. To avoid making generosity unappealing and prevent an altruistic child from being perceived negatively, don’t voice your approval of one child in a way that belittles another. A no-no example is: “Why can’t you be nice like your sister?”

  5. Give kids a choice

    It might seem counterintuitive, but giving preschoolers a choice about whether to share encourages sharing behavior. In a 2013 study, 3- and 4-year-olds were asked to share a sticker under three separate conditions. One group could choose to either keep the sticker for themselves or give it to someone. The second group could choose whether to give away the sticker or have the researcher put it away. The third group was simply instructed to give the sticker away. Then all the kids participated in a follow-up experiment where they were allowed to choose whether or not to share stickers with a new individual.

    “Almost all kids shared something,” researcher Tamar Kushner of Cornell University says, “but kids who were given costly alternatives shared more.” In other words, the kids who had to choose between giving away the sticker or keeping it for themselves in the first experiment were more generous in the second experiment. This suggests that sharing begets more sharing when kids are given a choice to share something at their own expense.

  6. Help kids discover that giving feels good

    Research shows that young children can understand the relationship between generosity and happiness, and they behave more generously when they do. Parents and teachers can reinforce this awareness in multiple ways. “First, just notice their spontaneous generous acts,” advises Diane Divecha, developmental psychologist at the Yale Center for Emotional Intelligence. Then, ask questions that encourage them to reflect on the experience of sharing with others. How did it feel to let your cousin play with your favorite toy? Was it easy or hard for you? Did it make you want to do it again? Chances are, the answer will be a resounding Yes.

This article is part of a series on how the science of character development can help parents promote honesty, diligence, gratitude, generosity, forgiveness, and curiosity in their children.