A new study suggests that having been a member of a teen gang means years later an adult is not only at higher risk of crime conviction and receiving illegal income, but also is less likely to have completed high school and more likely to be in poor health, receiving welfare and struggling with drug abuse.

Writing in the American Journal of Public Health, researchers from the University of Washington (UW) in Seattle, describe how they used 23 risk factors to identify children likely to join street gangs, then compared some who did and some who did not, and linked this to outcomes in adult years.

One of the researchers, Karl Hill, research associate professor in UW’s School of Social Work, says:

“It turns out that, like violence, gang membership is as much a public health problem as a criminal justice problem. Joining a gang in the teens had enduring consequences on health and well-being.”

The study looked at results from the Seattle Social Development Project, which was founded by study co-author Prof. J. David Hawkins, Social Work Endowed Professor of Prevention at UW.

Starting in 1985, the project followed 888 fifth-grade students, half of whom were from low-income families. The children attended 18 elementary schools serving neighborhoods with high levels of crime.

The children were interviewed every year until they reached the age of 18, then every 3 years after that, until they reached the age of 33.

From the interviews, and using a cluster of 23 risk factors, the researchers could identify children with a propensity for joining a gang. They then compared 173 teenagers who did join a gang with 173 who did not, but who also matched the same risk factors. So the only difference between the two groups was gang membership.

The 23 risk factors for making it likely that a child would join a gang were:

  • Individual factors: such as having antisocial beliefs, use of alcohol and marijuana, hyperactive and violent behavior
  • Family factors: including poverty, sibling behavior, parents with pro-violent attitudes, and family structure
  • Neighborhood factors: including extent to which neighborhood kids were in trouble and the availability of marijuana
  • Social factors: such as whether the child associated with friends who engaged in problem behaviors
  • School factors: such as academic aspiration and achievement.

The researchers assessed three factors in adulthood when the participants reached the age of 33:

  • Education and occupational achievement
  • Illegal behavior
  • Mental and physical health.

They found adult participants who were former members of teen gangs, were nearly three times more likely, between the ages of 27 and 33, to report engaging in criminal activity, more than three times more likely to be in receipt of illegal income, and more than twice as likely to have been in jail in the previous year.

Former teen gang members were also nearly three times more likely to struggle with drug abuse, twice as likely to report poor health, and twice as likely to be in receipt of welfare. They were also half as likely to complete their high school education.

The average age at which a child joined a gang was just under 15. None of the participants reported joining after the age of 19, and 60% reported being in a gang for a maximum of 3 years.

Lead author Amanda Gilman, a doctoral candidate in UW’s School of Social Work, says joining a gang was a turning point, leading to consequences that spread into other areas of the participants’ lives for years afterwards:

“Very few of them reported still being in a gang at age 27. The vast majority had left a long time ago, but the consequences stuck with them long-term,” she explains.

The National Institute on Drug Abuse, the Robert Wood Johnson Foundation, and the National Institute on Mental Health helped fund the study.

In July 2013, Medical News Today reported a study that found gang membership is linked to poor mental health. The UK researchers found unprecedented levels of psychiatric illness among young male members of street gangs and said the findings identified a “complex public health problem at the intersection of violence, substance misuse, and mental health.”