We humans are social creatures. Many, if not most, of us belong to groups or organizations related to our hobbies, business, profession, school, religion, political affiliation or some other aspect of our life. Much of this socialization is for enjoyment while our participation in other groups may stem from a sense of obligation or commitment.
Whatever the personal reasons for socializing, there seems to be an inherent tendency in humans to associate with one another; perhaps this stems from the earliest days of human history, when cooperative behavior was essential to the survival of our species. While practical reasons for group participation and networking persist today, the need to belong to cliques, clubs or organizations is also likely of psychological importance for many humans.
Then there are those, myself included, who enjoy solitude and prefer to interact with others as individuals or, at most, in small groups. Some might define this trait as antisocial and perhaps there is some truth to that assessment. On the other hand, privacy and personal freedom are often threatened when group mentality reigns supreme and meaningful, intimate dialogue is too often lost amidst the tweets and texting of modern society.