“Activism,” Dr. Ballard said, “is usually a different social experience than other forms of civic engagement.” While casting ballots and serving others both enjoy broad cultural support and are reliably gratifying, “activism tends to be more controversial. Activism can be empowering. But it can also be experienced as difficult and stressful.”

Indeed, the youth who engaged in activism — defined by the researchers as participating in a march or rally — enjoyed the positive benefits of greater educational attainment and larger incomes as they aged. But unlike those who only voted or volunteered, they also went on to engage in higher levels of risky health behaviors such as eating fast food, smoking cigarettes, using marijuana or binge drinking when they were between the ages of 24 and 32.

The study’s authors propose two possible explanations for this.

First, activists have, historically, often been members of counterculture groups where risk-taking may already have been the norm. Second, activists might become discouraged by the glacial pace of social change and turn to poor health habits to manage their frustration.

“We can help young people reframe their expectations from big ideas to small wins,” Dr. Ballard said. “The expectation shouldn’t be changing federal policy right away, but getting news coverage and raising awareness.”

According to Dr. Ballard, adults can also help teenagers feel that their activism is effective by making it about connection: “connecting with others, connecting with a cause and connecting with what’s already going on.” While most teenagers are too young to express their opinions by voting, participating in rallies is a way to make their voices heard. Those who want to join the effort to end school shootings can look to the student-led March for Our Lives movement to learn about the global rallies scheduled for March 24 — a Saturday, so there is no conflict with classroom time.

Of course the decision about whether to support or disapprove of a teenager’s activism is as personal as any in family life. Some adults will cheer on students who wish to participate in the walkout while others may oppose them or worry about the potential safety hazards, educational costs or disciplinary consequences of joining in. While some schools have threatened to suspend students who participate, legal scholars say students have the right to demonstrate unless they are disruptive. And dozens of colleges and universities said that any disciplinary actions against those participating in the protests would not affect their admissions decisions.

Looking at the issue from a social science perspective, adults should nurture adolescents’ efforts to catalyze political and social change because civic engagement can help teenagers grow. America has a long history of benefiting from the activism of young people; it’s good to know that the young people usually benefit, too.