Any coherent unit of order, no matter if it is biological or social from an organism, to a group, to organizations and communities, or nation states are established by two primary behavioral drivers. The first driver is a collection of coordinated activities that establish the integrity of the unit. A group needs a cementing bond to identify “self” from “other”. Self behaviors are aligned around the community. In biological terms, an individual organism is built on a framework of shared genetics and common epigenetics that form a cohesive bond. In the case of complex creatures like ourselves, this coordinated effort extends to specialized organs that coordinate activities to maintain integrity, and the ability to collectively obtain and metabolize nutrients that also maintain the integrity.
In social terms, integrity also has bonds, these bonds may be formed with a set of ideas. It could be the love of a sport, or the behaviors that support the commonwealth of the community. In all cases, the global principle is that there is some form of cohesive glue that establishes and maintains the integrity of the group, thus establishing a metabolism social order.
Behavioral expressions are the way a social group demonstrates and reassures itself that it is maintaining integrity as a cohesive unit. These behaviors are how a group nourishes itself. This can come in the form of ritual behaviors such social nit picking in chimpanzees, or in the case of humans, it could come in the form of uniform clothing, symbols, the wearing of hats, common language, saluting a flags, the saying of pledges, or taking of oaths either formal or informal. These things, and how they are valued determine the strength of the bonds that maintain the metabolism of the group.
The second primary driver of group cohesion is the development of a kind of “behavioral immune system” that has the capacity to reject any behaviors or contend with situations that are perceived to be potentially harmful or destructive to the integrity of the group. This social immune system that provides a defensive group cohesion engine is not unique to humans by any means. In fact, we are but one expression of this global biological driver that is threaded throughout the entire web of biological life from top to bottom. We see its expression biochemically and socially.
Here is one small example of this principle at work in the case of ravens, those that cheat are excluded from the protective network of cooperative birds. Ravens are able to cooperate when, for example, mobbing predators, but they exclude cheaters because they free ride on the assumed risks the others take. Here is more detail on this group cohesion behavior in ravens.
The Wisdom Of Life 