I hold such deep issue with this. Sure, there's an aspect to all living beings that they "self-preserve." But you seem to be implying here that it's part of human nature to be primarily self-interested, and if that's a correct assumption, it's one I believe to be deeply incorrect.
We can look around and see people acting in self-interested ways all of the time, but we can also see people doing lots of benevolent, good, supportive things for other people. In addition, it's no surprise many people go around day-to-day acting this way, given that they live in a system which encourages (née requires) them to do so.
Just because people can conform and act within a system, does not mean it is part of their nature. A system that actively encouraged and promoted the common good and communal caring among individuals would likely produce more of that behavior as well. Just because we see one type of behavior or another is not enough to decide that it's human nature.