We need to provide them with adult roles earlier in life.
I wonder whether teenagers who, for example, hack into company computers or join movements such as Isis do so because to be labelled a hacker, or jihadist, or a sports star or a pop star, is to be labelled an adult.
If they have not earned recognition as an adult, or at least as an embryonic adult while still adolescents then some of them seem to think that if they seize or highjack an adult role then recognition as an adult will follow. This way they oblige the adult world to confer an adult label upon them, be it as a tearaway who alarms the adult world, as a criminal or as a terrorist.
Treating other people with complete disdain, or in anger, or out of hate is not the only way to do this, but this is the route to a short-lived kind of adulthood, a forced recognition as an ersatz adult. But it is not the only way. Working and playing with adults, sharing interests or joining worthwhile endeavours, passing exams, gaining professional qualifications, earning the trust and friendship of older work-mates would seem a better route. (I well remember my parents sending me, aged eight, out to deliver Christmas cards to neighbours and I recall my pleasure in adult approval, away from school or family.)
What do we do with adolescents? Longer at school, in education. Longer away from the adult world and sometimes confined with other resentful adolescents, this is not just a waste of time for it provides a breeding ground for disaffection and worse. It should be no surprise that some teenagers kick over the traces. Wrongly but understandably they perceive adults as having all sorts of freedoms that are denied them. When they are denied freedoms, most basically to leave school and get a job, it is no wonder that some of them rebel. The obligation to attend school in some sort of guise is the clearest marker to many of them of their non-adult status. As long as they are compelled to be at school, or in college, under the direction of adults who are imposed upon them, they will see themselves as captives, forced to remain within the confines of childhood, and like those other captives, war-time POWs, they will seek ways to escape. Some of them will not merely want to escape a world that rejects them, they will seek to destroy it.