PTSD symptoms like hypervigilance are adaptive in combat but maladaptive in civilian life.

“And so we end up being a result of probably a lot of biology that's not that useful in the modern era. And I think in the brain for, say, let's say PTSD, right? A lot of veterans come back and they experience these PTSD symptoms and they're not at all useful back home, right? You know, they hear some loud noise and all of a sudden they're behind a car or they're behind a, you know, I've heard of folks, you know, jump and run behind a trashcan or whatever in the middle of San Francisco when they hear a loud noise. But if you put them back in the battlefield.”