We did know this. Maybe slightly less about positively extracting information but certainly about the diminishing returns as you get rougher with people, event

We did know this. Maybe slightly less about positively extracting information but certainly about the diminishing returns as you get rougher with people, eventually you just get bullshit from them. CIA and DoD absolutely knew this, they conducted very extensive research on it. There are two different things we were doing and just called it interrogation or enhanced interogation to dance around various laws. 1) we were punishing people and catering to the very lowest common denominator in the defense community. 2) we were attempting to send a message to other potential terrorists that "we are mean and will fight dirty" and attempt to dissuade them from even associating with people that are our enemies. This is partially why we have traded some terrorists for prisoners, that technique works best when you let them talk about it first hand. No idea if that stuff works and I have no idea about the cost of having the sociopaths that do that stuff free in our society but it had very little to do with extracting real intelligence