Primitive societies (in the classical sense) are closed, that is, they tend to draw a sharp line between "us" and "others". This separation is inherently human, a consequence of our evolution in small wandering groups trying to survive by exploiting anything outside. This is the default organization and it returns when social institutions fall. Grumpiness is so strong that we cannot avoid it in every aspect of our life. For every activity, we feel as members of groups.
In every situation we know who are "us" and who are "the others". We organize the world in concentric circles around us. It happens that "us" means "the people we trust for the problem I´m concerned now".. We have a sophisticated intuition to reshape the the circles around us. We even change to competing groups when changing a job. Some groups are soft and some more hard to reshape, for example, our country. But the country is not the limit of our group-ism. In fact we consider every human to be part of our circle for some global problems. But this is by no means the norm. Tribes, Urban tribes, mafias, sects, clans usually have very sharp limits. The loyalty to the group is enforced to avoid circles outside and even inside the group. Out of these extreme cases, the racism, etnicism, culturalims is very strong among uneducated people. Concern for other people outside of our “hard” group is a brain waste that is a luxury available only for very wealthy societies as I will try to demonstrate.
Evolutionary Game Theory rejects the survival of pure altruistic behaviors in any process subject to variation and selection. This happens to be in the case of biological and cultural evolution. It means that neither human nature nor social institutions can be selfless. Pure altruism can exist, but its existence is transitory. However, the altruism with those who are altruistic with oneself is a successful strategy. This can be called "asynchronous interchange". It requires a detailed memory of past favors due and given to every other person with which we reciprocate. The sophistication of the human brain permits a long decoupling in time between give and take. A more decoupled interchange occurs between friends and stable neighbors. The more stable is a group, the more can be the interval between give and take. Thus, if we enforce a group, then more decoupled interchange exist, since the uncertainty about being reciprocated disappears and more selfless appears to be (for the external observer) the interchanges.
Asynchronicity is important because the more is the interval between give and take, the more is probable to do it optimally, that is, to give, when I can, to other in true need and vice versa. This increases the net gains of the interchange.
Usually we reciprocate with people we consider our equals, but for the above reason, the interchange is more mutually beneficial if we give when we are in a good situation and vice versa. Charity, fraternity, and now, solidarity is the name for the evolutionary result of this optimization. The psychological impulse to solidarity cannot be based on any selfless impulse of the human nature because this simply does not exist, besides our self-deception about that. This is a derivative of asynchronous interchange trough the mechanisms described above. Simply, it is a logical outcome of our evolutionary history due to the cooperation inside groups.
So the solidarity respond to a instinctive, and thus selfish, calculus. Let’s return to the details:. It’s a good investment to be solidary in a group where reciprocity is morally enforced. However when it is less enforced, the more is the risk, but this risk does not affect our survival when we are wealthy enough. We can accept more risk when we have more resources. For this reason wealthy people can permit themselves to psychologically worry about larger circles of people. Our material wealth is the main fact that permits us to worry about larger and larger circles of people including humanity itself.
But that is not all the history. Sometimes the risk of not being reciprocated is maximum, but the gain in terms of social consideration among our equals in doing so is enough for the little value of the lost, given our wealth. Because the base of our human nature is selfish as any other being created by natural evolution, it would be strange to leave aside any opportunity for exploitation, and solidarity permits such exploitation: image seekers advertise themselves with theatric acts of solidarity in search of undeserved social prestige. Being the success in the anonymous urban civilization driven largely by image, it is logical the appropriation of solidarity by (corrupt) elites. Probably this has been the case in every period of history. Magnanimity is an attribute very appreciated by ruthless tyrants, but, probably, in no time like this has been advertising so powerful and the power of image so pervasive. Advertising our concern about wider circles can be both an exploitation in search of social prestige as well as a claim of wealth.
The opposite also happens. A person whose expectatives have declined sometimes release ties with other people, because being compelled to reciprocate with them can be too onerous. That if fact happens every day. Our instincts regulate the predispositions to reciprocate with others trough variations of our mood. When something happens that make us feel confident and successful, we are in good mood. At this moment, we are more prone to give favors . When we are angry we release circles of people from the obligation to reciprocate, and sometimes we advertise it loudly. When our wealth expectatives decrease, we stretch our circles.
That means that to give favors can be aggressive. To give something to someone in a group where the reciprocation is morally enforced puts the other in debt with this he advertises his magnanimity and wealth. It is a problem to accept a gift when we are not sure if we can reciprocate. Sometimes when there are great disparity in wealth between donor and acceptor, what is little for the first can be problematic to reciprocate for the second. In some cases, the second retaliate whit an even greater gift. This is the type of “gift wars” typical between neighbor tribes or clans know by Anthropologists. While this interchange maintains peace, they don’t cease to advertise his respective wealth and power to the other.
In some isolated islands, where war is too onerous and even suicidal, giving gifts is really like a war, where each part advertises the value of his gift and denigrates the ones of the other in offensive ways that in other geographical situations would initiate a conflict.
In terms of Game Theory, pure altruism is challenged by free riders that get the favor and return nothing. Reciprocal altruists reciprocate only with those that reciprocate; this avoids free riders. For this reason, we, as reciprocal altruists, have instinctive mechanisms of appreciation, to estimate the degree with which we reciprocate with who in each situation. Those that advertise its favors are second order free riders that exploit these mechanisms of appreciation.
This is the moment to remember the Christian urge to give without advertising. Since the beginning of society moralists observed the corruptive nature of advertised solidarity so they prescribed the corresponding moral rules. Such rules are now largely forgotten. It is not casual, but a tautology, that game theory assert the value of successful social rules that in fact only can exist in successful civilizations, at least in good numbers. For that reason, the forgetting of our traditional moral rules and social values and traditions is very dangerous.