the instinctive plane, yet evidences of the workings of purely instinctive elements are to be found, not only in the various forms of social conflict, but also in the forms of social attraction and of cooperation. While there is no single "social instinct" which can be invoked to explain the forms of man's social life, there is a whole series of reactions connected with instinctive forms of sociability, beginning with the parental instinct. That sociability is itself an instinctive, not an acquired, trait has been amply demonstrated by the researches of practically all modern sociologists. Professor Giddings especially has shown the instinctive attraction which exists between individuals of like physical and mental traits; and that such instinctive sociability, along with the acquired traits built immediately upon it, accounts for much in our social life. More recently Mr. Trotter, a British sociologist, has shown very conclusively the obscure reactions of the same instinctive sociability in practically all phases of man's social life.[1] Illustrations of this sort might be indefinitely multiplied, but it is not necessary to do so, because all this is what any thinker would expect who takes the biological view of life. While the sociologist is not yet ready to trace in any final way the workings of various instinctive reactions in human society, there can be no doubt that such a task is scientifically feasible, and will doubtless be accomplished in the near future.
All of this, of course, in no wise denies either the influence of intellect or of objective conditions upon social evolution. As the writer has elsewhere emphasized,[2] it is the intellectual elements in human social life which after all give it its distinctive character in contrast to the social life which we find among animals. It should be remarked, however, that these intellectual elements quite as often work in line with instinctive impulses as in the way of modifying them. Again, the influence of objective conditions is, of course, to be taken for granted in considering human society from the standpoint of instinct, since no instinctive reaction can develop unless the objective environment furnishes the appropriate stimulus. It is a mistake, however, to consider that such stimuli in the objective environment of themselves give rise to the activity; for nothing is more clearly demonstrated in the psychology of the present than that the organism frequently, indeed usually, seeks the stimulus. The stimulus is not that which causes action, but is rather the opportunity for action, the organism being self-active; hence the error of those who would interpret social life and movements entirely in terms of objective conditions. The "economic determinists," for example, are under the burden of showing that all the psychological and biological factors in human nature are mediated
