i think that's an overly simplistic statement. humans aren't machines designed to work toward selfish goals. viruses, may be. but not humans. people tend to group together and work towards a common goal even in the absence of some external enforcer.
and the other major component in a society is its beliefs. nobody forced the ancient Egyptian kings to build pyramids. they made them because of their beliefs. even capitalism is based on a set of beliefs. i think beliefs are a crucial ingredient ignored and criticized by everyone.
well a person would work with a team to achieve something which he wouldn't be able to achieve individually. That is by no mean less selfish.
in that sense i think u are right. we do everything either to feel good or not feel bad.
i think that kind of common sense selflessness is possible without so called socialism 


අපිනම් කඩෙන් ගස්ලබු ගෙනල්ලම නෑ මචං, ගෙදර ගස් හත අටක්ම තියෙනව, ඉතින් අපේ ගෙදර දවසක් ඇර දවසක් වගේ අනිවා ඩෙසට් එක ගස්ලබු තමා
