Yeah, I’m not sure there is much design or forethought to it?
I think people just flock through ideas and beliefs in this manner, rather like murmurations of starlings. No single bird decided that the flock will turn left, its more an expression of a complex system.
For humans the truth has nothing to do with it at all, it’s more a case of behaving predictably to signal trust patterns and loyalty during resource allocation. It’s a sort of compression algorithm for the individual to act in concert with many other individuals in order to create a mutually advantageous structure of some kind.
People fall into these patterns merely by following self interest, not because they followed any instruction. But yes, they can often be severely injurious to people outside of it.