Rhythm, have you by any chance read the book "On killing" by Dave Grossman?
http://en.wikipedia.org/wiki/On_Killing
Grossman being an army psychologist gives a pretty comprehensive account on different types of soldiers and how they deal with what is thrown at them.
http://en.wikipedia.org/wiki/On_Killing
Grossman being an army psychologist gives a pretty comprehensive account on different types of soldiers and how they deal with what is thrown at them.