I used to wonder why the rabbit didn't fight to the end when the dog caught it and was just carrying it around in it's mouth. Adrenaline had set in and the rabbit was just awaiting it's fate. I've also seen it in some of the vets I've dealt with who have PTSD. I've seen them in positions that are making them stress out, but they just "zero out." A lot of people think that they are just apathetic or ignoring the situation, but if you observe them they have a heavy pulse and may be sweating some. They have an adrenaline rush and can't function. Often they will tell you that they are stressing out and can't do anything. (I've noted that a lot of my coworkers will just talk over them or dismiss them, which ticks me off.)
So, the majority of the populace tends to be "soft." The majority of us on this forum know that in order to win a fight, you have to have the mindset that you are going to win the fight. But many citizens have no real fight experience or no military background... When Big Bad Jim goes to beat up on Little Mary Meek, Little Mary thinks that it's all over because on TV the big dude always beats up the little person. Mary's adrenaline is going to help her die. But when Big Bad Jim tries to beat up Big Bertha? Well, Big Bertha ain't got no time for that! She has a lot of ire and anger and she's going to teach this overgrown snot nosed brat a thing or two! Big Bertha's adrenaline is going to help her fight, and her mindset isn't one inclined to back down. Now Bertha's wooden spoon isn't going to do much harm to Big Bad Jim, but he's rattled all the same so his adrenaline is going to help him flee. His mindset was that Bertha was an easy target, just like Mary. But when Bertha fought back, Jim went from "winner" to "looser" really quick.
I'm going to keep looking for this study. My Google-Fu is weak. But I'm sure I have a copy of it in one of my folders from my Academy.