Humans are not individuals. Neither are they social animals, where society is an abstract entity, such as a nation or a religious community. Humans are tribal animals. Just like other primates, they are at home in groups of a few hundred individuals held together by kinship and shared culture. Ever since the appearance of larger social entities, most humans have lived in villages organized along tribal lines. As of late, humans living in towns and cities keep looking for ways to satisfy their tribal needs. These needs go so deep that they can be thought of as an instinct. The tribal instinct has been honed for millennia, and it cannot be replaced by larger social entities. As Charles Darwin noted in his Descent of Man (1871), a tribe possessing a high degree of communal spirit, where one member would always be ready to help another, would be more successful than other tribes, and this would provide another example of natural selection. Only the last five millennia or so have disrupted this evolutionary process, and this is true only of urban societies. Although an ever-larger number of humans now live in cities, they can always return to tribal life if cities come in danger, as is likely to happen with dramatic climate change. This is where the tribal instinct will come to the rescue of endangered humans.

Addendum (October 13, 2015)

The tribal mode of existence has been uppermost on my mind lately. And so is primitive communism that goes with it. Which is why I see the ravages of climate change and environmental degradation in an entirely different light than most of my fellow humans. As I like to say, the horrors that can be expected in the short and medium run are well worth the trouble in view of the bliss in the long run. The same holds for the very long run, which covers several glaciation cycles yet to come. Looking back, the human species as we know it has been around for at least a hundred-thousand years while the interruption in the tribal mode of existence has lasted a bit more than five-thousand years. So-called civilization is but a blip in human experience. Chances are that the next few glaciation cycles will not be very different in this respect. Five percent give or take a few! It is thus not surprising that my optimism about the distant future is growing by the day.