Can beliefs be true or false or are there only different survival strategies?

[bmcnicho]

Clearly survival pressures influence our worldviews greatly, but I'm contemplating whether there could be any truth value to beliefs independent of the evolutionary and psychological factors that produce them.  Is treating people with compassion morally right in some higher sense, or did it merely benefit our ancestors survival to be able to cooperate in groups?  Are virtues like competence, resilience, rationality, strength, creativity and love actually valuable or do they only happen to be useful for a group of apes living on a rock in space?

This line of thinking is leading me towards a caricature of postmodernism, where every perspective could be equally correct, so it's sort of impossible to really reach conclusions about anything.  I guess the more spiritual answer would be that Truth lies beyond thoughts and the mind, but I'm not ready to give up on the potential value of more relative truths.  Playing a game of trying to deceptively 1-up the other meat blobs around me doesn't seem all that compelling to me.  But if all our religions and philosophies are a bunch of nonsense our ego-minds invented then I don't see what else is there. 

The side of me that's an idealist tends to conflict with the side that's a rationalist, but that's what I've come up with so far.