Finally it is of the highest importance in studying primitive peoples to make the distinction between the acts which have to do with persons of the same social group, and those which have to do with strangers. One of the principal causes of the charge of egoism made against primitive peoples is to be found in the fact that this dualism of ethics [[392]]is forgotten. In the passages I have cited (those from Maine and Steinmetz, for instance) the great difference between acts committed within and without the group is brought out. We have seen that the Indians of North America, although very altruistic toward those who form the same group with them, as also toward their guests, are the most pitiless enemies of those who attack their independence or their hunting ground. Now it has been by these last acts that these peoples have been generally judged, a wholly wrong method, since the “dualism of ethics” has always existed. Great would be the astonishment if any one were to maintain that the South African war proved that the English were a nation of murderers and incendiaries. Yet this is just the sort of reasoning that is applied to primitive peoples.[31]
How does it happen that some animal species are social while others are not? It is impossible to maintain with some authors that sociability increases according to the degree of development attained by the animal.[32] Certain insects, for example, are endowed with pronounced social feelings, while the cat tribe and some kinds of birds are on the contrary unsocial. Nevertheless the latter occupy a higher place in the scale than the former. The explanation, then, must be sought elsewhere.[33]
There are divers reasons that draw a more or less considerable number of animals to one place—the fact of being born in the same locality, for example. Most animals are social when they are young, even those which are no longer so when full-grown, like the arachnids. Another cause that brings animals together is emigration towards a country because of great changes of temperature. A third cause, probably the most important, that unites animals of the same species is the abundance of the food-supply of certain countries.
However, the occasional assembling of animals does not explain why certain animals are social while others are not. Lions, for example, often meet in places where they come to drink, and yet do not become social. It is not probable that there are animals who have remained together because they have comprehended the advantages [[393]]of a life in common, for this would suppose an intelligence on their part which it is difficult to attribute to them. In order that these animals should remain together they must find it agreeable, and disagreeable to be isolated.
When we study the social species of animals we notice that the life in common is in general one of their most powerful weapons in the struggle for existence, a weapon without which it would be nearly or quite impossible for them to maintain the fight. Consequently the animals for which the life in common is advantageous and which possess social instincts stronger than others, have, when brought together by any cause whatever, a greater chance to survive.[34] Per contra the animals who have to stalk their prey have more chance of surviving when life in common is disagreeable to them. It is therefore by survival that social feelings are developed in some species of animals and not in others.[35] Habit, and the tendency to imitate increase these feelings considerably.
The advantages to certain species of animals resulting from life in common are of two kinds; in the first place a better defense against their enemies, and in the second place greater ease in procuring subsistence. Wild cattle give us an example of the first case; while the wolves who in winter gather into packs for purposes of the chase, because food has become scarce, furnish us an example of the second. For other animals (like the simians) social sentiments are helpful in both ways.
It is unnecessary to amplify further upon the two ways in which life in groups is of advantage to certain species of animals. We have yet to turn our attention to the qualities developed by the group struggle for existence.
One of the principal characteristics of social animals is the pleasure they experience in living in common, so that a social animal is unhappy if he is separate from those of the group in which he lives. Further it is necessary that the animal that cannot live alone, and is happy with his group, should also feel a sympathy with that group. Pleasure or its opposite felt by any individual reacts upon the whole group. A social being will try then to favor the interests of his fellows as far as he can, and in so far as he comprehends these interests. This sympathy will not extend to the whole species but only to the group. [[394]]The general interest of the group does not permit the sympathy to embrace the whole species, but on the contrary requires one group to fight the other if, for example, the latter interferes with its food-supply. And even within the limits of the group the general interest may demand that a sick or wounded individual be abandoned, when by its presence it would for example, attract beasts of prey, and thus put the existence of all in danger.
Highly developed sympathy produces the spirit of sacrifice, which impels the individual to assist his companions sometimes even at the risk of his life.[36] This quality is reinforced by the desire of gaining the praise and avoiding the blame of companions, which desire in its turn is brought about only by the life in common. For the one that lives in conjunction with others, and takes pleasure in doing so, whose interests are those of the members of the group, must be sensible of the approval or disapproval of his acts felt by others, since their feelings of pleasure or displeasure react upon himself. The lack of the power of speech among animals, however, limits the force of praise or blame among them.