We all want our kids to have purpose in life, whether that’s raising a family or improving education for kids around the world. But, today, a surprising number of young people are without purpose. In researching his book The Path to Purpose: Helping Our Children Find Their Calling in Life, Stanford University psychologist William Damon found that only 20 percent of youth age 12 to 26 had found something meaningful that they wanted to dedicate their lives to. Another 25 percent of youth were “drifting,” without a wider purpose, or any plan to find one, and the rest were somewhere in between. So, what exactly does it mean to have purpose, and how can we prevent our kids from drifting?

Purpose, says Damon, has two components: First, it's a goal that’s meaningful to the child, not one that someone else assigns to him or her. Second, it makes a difference in the world. “It can’t just be about me,” says Damon, “it has to be some engagement in the world where you’re trying to matter.” It doesn’t have to be creating change around the world, however, meaningful purpose could come from making customers happy at their summer job or raising a family.

Richard Weissbourd, lecturer on education at Harvard, studied idealism in kids for his upcoming book The Parents We Mean To Be. Using the idea of idealism as “convictions about and a commitment to a better and more just world,” Weissbourd found that most high school students wanted to contribute to the world on some scale, and that the nature of their idealism was heavily influenced by what they’d just learned in school. In college, idealism is often shaped by the latest fad, whether Darfur or AIDS in Africa. And, many kids are frustrated with community service projects taken on with the goal of getting them into college. Weissbourd calls those projects “a kind of community service Olympics [where] kids are vying for the most high profile service.”

Kids develop their sense of purpose as early as elementary school or as late as young-adulthood. While you can’t force your child to find purpose, you can help direct him. In today’s world, without a unifying movement like Civil Rights or World War II, it can be difficult to find something to get passionate about. Even jobs are more confusing—kids aren’t just going into the family business of fishing or farming—and marriage has been postponed, making the idea of family more elusive. “Because things are so complicated, it’s all the more important that a kid develop a good inner compass,” says Damon, “the kids who don’t get it really flounder because there isn’t anything ready-made that they can fall into.”

So, how can you help your child find purpose? Here's are some guidelines to get you started.

Model it for your kids: “A lot of a sense of purpose develops when you’re in a family that lives and breathes idealism and purpose,” says Weissbourd. Around the dinner table after work, driving to church or a volunteer activity, talk to your kids about your work and purpose, why it’s important to you, and what it means.

Encourage their interests: Ask your kids what they’re interested in and help them pursue those interests, even if it’s not what you’d imagined they’d do. Along the way, beware of the service Olympics and help them find service activities that will help them make a real difference, even if it does end up on a college essay.

Understand that they likely won’t follow you: Most kids who have a clear sense of purpose don’t get it from their parents, says Damon, but parents are critical in supporting and encouraging purpose.

Be persistent: If your child seems direction-less, they’re hard to talk to and may shut down when you press them for more information, but, Damon recommends, keep pressing, eventually they’ll hear you. A delay isn’t really a problem; everyone is taking longer to figure themselves out these days. “Parents are in it for the long haul,” says Damon, “be patient and persistent, and keep offering kids something, eventually they’ll hear it.”