Share story

It’s pretty much a no-brainer that a kid who joins a gang — even briefly during adolescence — stands a greater chance of committing crimes, using drugs and winding up in prison as an adult.

Less obvious, however, are the lasting consequences of gang membership on physical and mental health, educational and occupational prospects, and reliance on public assistance like welfare, according to a University of Washington research paper published this month in the online edition of the American Journal of Public Health.

Based on a study of 808 participants who were all fifth-graders in Seattle Public Schools when they were first interviewed in 1985, the paper utilizes “life course theory,” suggesting that gang membership puts kids on a trajectory that disrupts and rearranges the normal opportunities of school and work and negatively impacts them well into adulthood.

The paper — titled “Long-Term Consequences of Adolescent Gang Membership for Adult Functioning” — is the first study of its kind to cast involvement in a gang as a public-health issue, not just a criminal-justice one, said professor Karl Hill, who supervised Amanda Gilman, the doctoral candidate who authored the paper.

This week, save 90% on digital access.

Gilman, Hill and J. David Hawkins, an endowed professor of prevention, are the journal article’s co-authors.

The paper, which will also appear in the journal’s print edition in May, was based on three decades’ worth of research.

In 1985, 808 Seattle fifth-graders attending 18 different public schools in high-crime neighborhoods across the city became the very first research subjects for the Social Development Research Group (SDRG), which is part of the UW’s School of Social Work. More than half of them came from low-income families.

The study, known as the Seattle Social Development Project, was funded by the National Institute on Drug Abuse for the past 25 years.

The project was focused on providing teachers and parents with better instruction methods and intervention techniques, “evidence-based tools they could use to keep their kids on the right track,” Hawkins said.

Participants were 10 years old when the study began and were interviewed along with their parents and teachers. Now closing in on their 39th birthdays, 92 percent of the original study participants are still involved in the project and submit to lengthy interviews about their lives every three years.

Over the years, their answers have led to roughly 100 research papers — on everything from risky sex to high-school graduation rates — and spawned 20 doctoral dissertations.

Because participants self-report on illegal behavior, their identities are known only to data collectors, while researchers like Hill and Gilman know participants only by the random code numbers assigned to them.

In the late 1980s, after gang members from Los Angeles and Chicago migrated here to establish a crack-cocaine market, interviewers began introducing questions about gangs to the participants, then in their early teens.

Of the 808 participants in the study, 21 percent reported joining a gang, most when they were around 15 years old, according to Gilman’s paper. Slightly more than two-thirds of those who joined a gang were male and almost 42 percent of them were African American, mirroring national numbers that show a disproportionate number of gang members are male and members of ethnic groups.

Of the 173 gang members in Gilman’s sample study, more than half were in a gang for three years or less, she said. Only 17 — less than 10 percent — reported still being in a gang at age 27.

“For most kids, gang membership is a short phenomenon,” said Hill, noting most are part of a gang for 12 to 18 months.

“It’s not a lifetime commitment but we wanted to see if there were lifetime consequences.”

For her study, Gilman didn’t use data from all 808 participants. Instead, she employed a “propensity score analysis.” She matched each of the 173 participants who reported joining a gang with a peer from a similar background with similar risk factors, then statistically controlled for 23 variables until “the only difference” between them was that “one group joined a gang and the other didn’t.”

Her findings present a stark picture: Joining a gang is a life-changing turning point in a young life. Worse yet, people who quit gangs at a young age didn’t really fare any better in the long term than those who were still involved in a gang in their mid-20s.

Not surprisingly, at ages 27, 30 and 33, study participants who had at one point belonged to a gang were nearly three times as likely to have committed a crime in the previous year, more than 3½ times as likely to report receiving illegal income and more than twice as likely to have spent time behind bars in the previous year compared with those who never joined one, the paper says.

Compared with their peers who hadn’t joined gangs, former gang members — again at ages 27, 30 and 33 — were also more than 1½ times more likely to receive public assistance, three times more likely to abuse drugs or alcohol, and reported higher instances of depression, anxiety and poor physical health.

They were also more likely to be the victims of violence than their non-gang-involved counterparts and were about half as likely to graduate from high school as those who “had never joined a gang but shared similar risk backgrounds,” the paper says.

While there are a few programs nationally that are showing some promise in helping to prevent young people from joining gangs, there really is no gold standard or evidence-based model to point to, said Hill, who hopes research like Gilman’s can help change that.

Young people joining gangs is “not a police issue, it’s a public-health issue,” he said. “It’s not up to the police and courts to solve the gang problem. It’s up to communities and families and schools.”

Sara Jean Green: 206-515-5654 or

Custom-curated news highlights, delivered weekday mornings.