I think one of the difficulties here is that you may have a logical reason for cooperation leading to more pleasant life or increase production in a civilized s

I think one of the difficulties here is that you may have a logical reason for cooperation leading to more pleasant life or increase production in a civilized society, etc. but when it comes down to being in a gulag, you often need stronger reasons for morality than a belief that it will make your life more pleasant. The short term consequences of an action (e.g. stealing) may seem more pleasant [satiation of hunger], the long term consequences may seem to be unlikely to occur [because of imminent death]. Religion provides much stronger reasons for living in a certain way (belief in afterlife, that justice ultimately prevails regardless, consequences of character you've developer for eternity, and that human life is sacred and valuable beyond the grave, etc.). Reasons that neither death nor deprivation can change.