Does religion make armies stronger?

[Psychonaut]

I guess they're primarily fighting for survival. The buddies part may play a role, but that's already a statement made after the action.

Well, the heroic acts on the battlefield are often self-sacrificial. I'd think they would qualify as statements in the moment, in a manner of speaking: mute testimony to their love for their brothers, even into death.

I've seen, and heard of similar behaviours in other species, namely, chimpanzees. There are times when a healthy male will put themselves in danger and possibly die for other members of the troop, by baiting the predator toward themselves, in order that the troop may escape. It lends a lot of credibility to the idea that we are playing in to very ancient traits when engaging in defensive, and offensive violent behaviours as a species. A set of behaviours that our species is yet to overcome (violence that is).

The reason I'm interested in religion's ability to influence this ancient trait, is because it seems as though it further confirms a current theory I've been following in psychology. 

I couldn't explain it better than these guys (as they're the ones who've helped form the theory) 
So i'll provide a link to the documentary that I found on vimeo if you are interested.

https://vimeo.com/104959002


P.S you may have to look around for the other parts to the series, which I'm sure are by the same uploader, as it's set in 3 parts from memory.