The reason the teenage years have always been such a perilous time, Steinberg says, is that the incentive processing system reaches its full power in early adolescence while the cognitive control system doesn’t finish maturing until you’re in your twenties. So for a few wild years, we are all madly processing incentives without a corresponding control system to keep our behavior in check. And if you combine that standard-issue whacked-out adolescent neurochemistry with an overloaded HPA axis, you’ve got a particularly toxic brew.
