Not necessarily. Gang members, if they don't end up in jail (and can't get a job afterwards as felons), too, tend to settle down in early to mid-30es.
What we call "gang activity", to a degree, is also very stupid behavior of young people. But they do get in groups to commit it. I have seen kids get in a juvy for breaking into a pizza shop and stealing pizzas - in a group. Not a dangerous thing, but the group factor made it look like a gang.
Now, impulsive behavior of young men in typically group-driven. On a positive note, one can work with a group (e.g., AA or NA). These lone serial killers are a problem because they are typically outside the groups.
I think we may agree. I’d think it likely that gang members tend to settle down in their 30s—or be in prison. Either way, not adding as much to the crime statistics—which is what I was saying.