My answer to the Quora question: Why do most humans still have a deep psychological need to have tribal affiliations?
Tigers have claws, birds have flight, fish can swim. The only thing human beings have is each other.
I know I just made an oversimplification. But it is not far from true.
One of the most important factors behind human beings’ survival was their ability to group in large numbers. Even today, this tendency remains. In fact, one explanation behind why many people have stage fright (glossophobia) is that it is a manifestation of our innate fear of being rejected by other members of our tribe.
If a member of an early human tribe wasn’t useful to the collective, he could end up on the periphery of society. Being alone was pretty much the kiss of death. There was strength in numbers and only by understanding this did humankind get where it is today.
In fact, this is why even today, leaving a community seriously messes up an individual’s life. In many religions, apostacy is a crime. Marrying outside your caste gets you killed sometimes. There were even times when it was considered bad to leave your country and travel to other lands.
Religions remain, nations remain, and football clubs remain. This is because anything large and all-encompassing defeats the purpose of belonging to a tribe. A tribe is not only an “us” label. It is also a “not-them” label. Many tribes define themselves by what they oppose.
We are a tribal species. The tendency to gather together in tribes made us what we are.