In 2005 Afghanistan had a 7.6 earthquake. It killed nearly 18,000 people. Most of them were kids, because they were indoors, in school, when the quake hit. I'm reading about this when I come to as horrifying a sentence as I have ever read.
Strangely, the vast majority of those dead schoolchildren were girls, and as the debris was cleared away and the bodies were recovered, the explanation for this imbalance slowly emerged. While the boys had tended to race to safety by bolting out the windows and doors, most of the girls had instinctively huddled together and perished.
(Mortensen, Greg. 2009. Stones into Schools. p168)
How beaten down does a person have to be in order to extinguish their basic instinct for survival? How hopeless do things have to get before you don't even try to get away, just crouch down and hope you live through whatever happens to you?
It's a coping strategy for victims of horrendous abuse, I know, the type that results in multiple personalities and such. Lab rats show it as Learned Helplessness. When they figure out that nothing they can do will prevent being hurt, they just cower down and whimper, and keep on acting that way even after you change things so that escaping would be easy, they still don't even try.
As horrible as it is even to think very much about this happening to a few animals in a lab, here it is happening to an entire country, at least to all the girls. The boys fought to survive. The girls had already been trained.