In sixth grade, a boy’s friends leaned so heavily on him for emotional support, his teachers grew concerned and mentioned something to his mother. “When I asked him if he felt overwhelmed, he burst into tears,” she told me. “One girl in particular was unloading serious issues that were beyond his years or ability to handle, but he felt he had to listen, be kind and help her, because that’s all we ever tell our kids.” The greater his classmates’ distress, the more he felt compelled to give and the more depleted he felt.

As middle-schoolers separate from parents and other authority figures, they invest more in their friendships. “There’s a lot of stormy weather, but it’s also a time of deeply tender moments of shared vulnerability,” explains Helen Riess, an associate professor of psychiatry at Harvard Medical School and author of “The Empathy Effect: Seven Neuroscience-Based Keys for Transforming the Way We Live, Love, Work, and Connect Across Differences.” “This is when some kids just keep giving and giving because they confuse moral virtue with emotional exhaustion.”

As tweens sort out their identity, they want to be seen as trustworthy and caring, but insecurity can generate pressure to be “the best.” “For some, that translates into focusing too narrowly on personal achievement with little attention to others’ needs,” says Adam Grant, an organizational psychologist and author of “Originals,” “Give and Take” and “The Gift Inside the Box.” “For others, there’s a clear focus on being generous, but they take it too far — they try to become the most altruistic. To paraphrase the show ‘Silicon Valley,’ ‘I don’t want to live in a world where someone makes the world a better place better than I do.’ ”

We’re experiencing an unprecedented decline in empathy and can’t afford to discourage kindness, but we also need to impart lessons about reciprocity, healthy boundaries and the limits to generosity. Here are seven ways parents and educators can teach tweens to give to others without sacrificing themselves.

Applaud them for taking small steps

In middle school, a child might willingly adopt the role of peacemaker, mediator or adviser, but then feel stuck, says Lisa Damour, psychologist and author of “Untangled” and “Under Pressure.” “With groups of friends, they’re doing a dance, everyone has their steps, and it’s very hard to change their steps without changing the dance.”

Because tweens operate in complex networks, they have less autonomy and mobility in their social lives than adults. “One bold announcement at lunch won’t effectively shift firmly established dynamics,” Damour explains. A child could decide to stop sitting with a specific friend at lunch, but then get assigned to the same group project or have to play on the same team. Recognize that restoring equilibrium takes time and courage, and applaud them for making even small changes.

Honor their need for autonomy

Tweens may be open to help, but then shut down or rebel if an adult tries to dictate their behavior. It can be excruciatingly hard to watch your child experience bumps and bruises, but “the key for parents is not to shield them from that inevitability, but to make sense of it,” says Daniel Pink, author of “When,” “Drive” and other books. “That begins by working to build an environment of psychological safety so that young people know they can be who they are and admit difficulties without negative consequences or judgment,” he explains.

To respect their desire for independence, point out when a friend confuses emotional support with friendship, but don’t insist that they drop that friend. Highlight red flags, such as feeling pressure to keep a secret, dreading someone’s call or feeling physically worn out. Say, “That sounds really tiring. How are you managing this? How are you recharging? What do you want to see change?”

If you think a friendship is one-sided but your child isn’t complaining, Damour recommends telling them: “I feel really torn about your friendships. On the one hand, I love seeing how generous and thoughtful you are. On the other hand, I wonder if those friendships are sustaining for you or draining you.”

When Peggy Orenstein, author of ­“Cinderella Ate My Daughter,” “Boys & Sex” and other books about teens and tweens, senses that her teen daughter’s friendships aren’t equitable, she’ll try to help her articulate where to draw the line. “She may not come to those conclusions right away, but the fact that I’ve put it out there may give her some language and insight that help her see it sooner,” she says. “I’ve planted those seeds.”

Connect the dots through stories

Parents can use parables to demonstrate the difference between self-sacrifice and reciprocity. In Shel Silverstein’s classic book “The Giving Tree,” for example, a tree gives a boy everything from her apples to her branches until she’s only a stump with nothing left to give. In contrast, in Grant’s “The Gift Inside the Box,” co-written with Allison Sweet Grant, a mysterious package encounters a series of selfish kids until he meets the perfect recipient: a little girl who views him as a special gift for someone else.

Read both stories, then pose questions that encourage critical thinking, such as: “What would make the relationship between the tree and the boy less lopsided? Why does the box steer clear of all the ‘me, me, me’ individuals? What’s the difference between pleasing others and helping them?” As Grant explains, “Being generous doesn’t mean you never say no. It means you’re thoughtful about who you help, when you help and how you help.”

Brainstorm solutions together

“Remind your child that they don’t have to solve everyone’s problems,” says Michele Borba, author of “UnSelfie: Why Empathetic Kids Succeed in Our All-About-Me World.” She recalls one child who became the “Dear Abby” of her middle school. “Her mother would say, ‘You know, Jenna, they’re going to have to manage this on their own,’ ” then role-play remedies with her, such as recommending to her friend that she see the school counselor or asking them to wait until the end of the day. “If a kid postpones the intervention, the friend usually figures it out,” Borba says.

Underscore that helping should be a shared responsibility. In the school where I am a counselor, I demonstrated this by adapting Grant’s Givitas exercise. I had my sixth-graders write on an index card something that they wanted or needed but couldn’t provide for themselves. The requests ranged from, “I want to get better at basketball,” to, “I could use a friend.” I then asked the students to put their name on any card with a request they could fulfill. To their surprise, no card was left empty. They realized that everyone wanted to help, and no one had to carry an undue burden. When kids understand that empathy is a two-way street, they’re less likely to give to someone who consistently takes advantage of them.

Challenge gender stereotypes

Parents need to challenge the stereotype that girls are responsible for emotional labor or that “real men” suppress their feelings. “There’s a common dynamic where girls will give, give, give of themselves in processing boys’ emotions until it’s harmful to them physically, and it’s equally harmful to boys,” Orenstein says. “We have an epidemic of male loneliness and suicide, and we have to be aware of how equitable the divide is, and how much boys are learning to connect with one another and not just the girls or women in their lives.”

On the positive side, a father’s perspective may be particularly useful to daughters because men are socialized differently. “Fathers should pay attention to where their daughters fall on that spectrum and be talking about relationships, too,” Orenstein says. This isn’t to discount the importance of mothers. “As women, we have to interrogate how we conduct our relationships and be role models,” she adds.

Mention when they're out of their depth

Just as tweens would never feel qualified to help someone who needs heart surgery, they’re not equipped to deal with serious depression or intense emotional issues. “Tell a child, ‘You’re out of your league,’ ” Riess says. That’s often an effective approach because the last thing kids want to do is to cause harm.

When well-meaning, generous tweens spend a huge amount of time offering a friend support at the cost of their own sleep or mental health, Damour suggests implementing a three-part plan: Reassure the givers that not only are they unable to provide the appropriate support, but many adults also don’t have the necessary specialized training. Help them get their friend the support they deserve, then help them navigate their friend’s needs going forward.

“I’ll say, ‘When your friend is engaging you appropriately around things 13- or 14-year-olds talk about — outfits for the eighth-grade dance or something someone said on Instagram — feel free to be all in and share in their joy,’ ” Damour says. “Should your friend wander over the line, say, ‘That sounds awful, are you talking with a grown-up about it?’ ”

Teach them to spot emotion contagion

Research shows that moods and emotions are contagious, and this is especially true for middle-schoolers.

“What’s counterintuitive is that most feelings are mutual, so if you’re getting really overwhelmed or feeling scared, then your friend is probably overwhelmed, too,” Riess explains. “The more intense the feeling, the more they think they need to stay on the phone, but they’re picking up the other person’s desperation and should realize, ‘I’m in over my head.’ ” They may feel like they’re giving up on a friend who is in a downward spiral, so explain that they’re playing the critical role of helping their friend get the comprehensive care they need. “We teach children to feel it all, and then they try to take on the world and they can’t,” Borba says. “An empathetic child can get vaporized.”

This isn’t about extinguishing generosity; it’s about helping kids develop healthy relationships and strike a balance between compassion and self-compassion. As Riess points out, “Self-neglect is a really perilous approach to life, because when you run on empty, you’re of no use to anybody.”

Phyllis L. Fagell, a licensed clinical professional counselor, is the author of “Middle School Matters,” the school counselor at Sheridan School in the District and a therapist at the Chrysalis Group. She tweets @pfagell and blogs at phyllisfagell.com.