I agree that we're naturally social, which means we live in groups to survive. If by naturally "authentic," though, you mean to speak of our sociobiological function, that function would still be set by the long Stone Age, which means we're adapted to live in small groups, not huge cities, kingdoms, or nations. So civilization would still be inauthentic or maladaptive, even if we take our cue from nature. I think it's easier being true to yourself when living in a tribe, clan, or club than when you have to adapt to enormous institutions, like a corporation or an organized religion.