...that the state is a creation of nature, and that man is by nature a political animal. And he who by nature and not by mere accident is without a state, is either a bad man or above humanity; he is like the "tribeless, lawless, hearthless one," whom Homer denounces—the natural outcast is forthwith a lover of war; he may be compared to an isolated piece at draughts.
Or, of course, the Stanford Prison Experiment: http://www.prisonexp.org/
More subtly: the notion of American "rugged individualism," and the group with which many (right-leaning) "indiviudalists" unironically self-identify.
On HN, I suspect there's high participation the group of rational, logical thinkers who consider themselves superior to the fears and insecurities that compel the typical "joiner."