facts that psychology can explain, and these additional data accordingly require treatment by another science.

My conclusions as to the relation of psychology to culture are, accordingly, the following: The cultural facts, even in their subjective aspect, are not merged in psychological facts. They must not, indeed, contravene psychological principles, but the same applies to all other principles of the universe; culture cannot construct houses contrary to the laws of gravitation nor produce bread out of stones. But the principles of psychology are as incapable of accounting for the phenomena of culture as is gravitation to account for architectural styles. Over and above the interpretations given by psychology, there is an irreducible residuum of huge magnitude that calls for special treatment and by its very existence vindicates the raison d’être of ethnology. We need not eschew any help given by scientific psychology for the comprehension of specifically psychological components of cultural phenomena; but as no one dreams of saying that these phenomena are reduced to chemical principles when chemistry furnishes us with an analysis of Peruvian bronze implements, so no one can dare assert that they are reduced to psychological principles when we call upon psychology to elucidate specific features of cultural complexes. The ‘capabilities and habits acquired by man as a member of society’ constitute a distinct aspect of reality that must be the field of a distinct science autonomous with reference to psychology.

II. CULTURE AND RACE

If culture is a complex of socially acquired traits, it might appear that race could not possibly have any influence on culture, since by racial characteristics we understand those which are innate by virtue of ancestry. This, however, by no means follows. In order that certain traits be acquired, a certain type of organic basis is an absolute prerequisite; a chimpanzee or a bat is not able to acquire human culture through social environment. From an evolutionary point of view it appears, therefore, very plausible at first blush that within the human species, likewise, differences in organization should be correlated with the observed cultural manifestations of varying degree and complexity. There was, undoubtedly, some stage in human evolution where the organic basis for culture had not yet been acquired. Can the several races be regarded as transitional forms, each possessed of certain capabilities determining and limiting its cultural achievement? This question can be viewed in two ways. Comparative psychology may give us direct information as to qualitative and quantitative racial differences that would affect cultural activity. Or, we may infer such differences as the only possible causes for the observed cultural differences. Both modes of approach are helpful for a comprehension of the problem.

Until recent years the psychological evaluation of primitive tribes rested largely on the offhand judgments of travelers and missionaries. With the advent of more exact psychological laboratory methods, these have been, in some measure, applied by competent investigators to aboriginal populations. Unfortunately, the results hitherto secured are somewhat meager. There are technical difficulties, among them the necessity of examining fairly large numbers of individuals in order to get a good sample of the population. Worse still, laboratory methods are most effective in regard to what may be called the lower mental operations, which partake almost more of a physiological than of a strictly psychological character. Clearly enough, what we should be most desirous of knowing is how primitive compares with civilized man in logical thought and imagination. But these are precisely the things not readily tested, and here the additional technical difficulty comes in that they can hardly be examined at all without a far more intimate knowledge of the native languages than the investigator is likely to command. Nevertheless, something has been done and I will attempt to present as briefly as possible the essential results, following Thorndike’s convenient summary.[1-ii]

Although some observers have attributed unusual acuity of sense perception to the more primitive peoples of the globe, the investigations of Rivers, Woodworth, and others in the main establish the psychic unity of mankind in this regard. For example, though the Kalmuk are renowned for their vision, only one or two of the individuals tested exceeded the European record, and while Bruner found Indians and Filipino inferior in hearing a watch tick or a click transmitted by telephone, the fairness of these tests for natives unused to such stimuli has been reasonably challenged. In their reaction-time tests, widely different groups were very similar. In the tapping test, measuring the rate at which the brain can at will discharge a series of impulses to the same muscle, marked differences were also lacking; but when accuracy as well as rapidity were examined, the Filipino seemed decidedly superior to the whites. Optical illusions were shared by all races tested, which indicates, as Woodworth points out, that simple sorts of judgments as well as sensory processes are common to the generality of mankind. Woodworth subjected his subjects to an intelligence test, demanding that blocks of different shapes be fitted into a board with holes to match the blocks. In speed the average differences between whites, Indians, Eskimo, Ainu, Filipino, and Singhalese are small and there is considerable overlapping. On the other hand, the Igorrote and Philippine Negrito, as well as a group of supposed Pygmies from the Congo, proved remarkably deficient. “This crumb,” concludes our investigator, “is about all the testing psychologist has yet to offer on the question of racial differences in intelligence.”

It may well be, as Thorndike suggests, that if higher functions were studied, more striking differences would be revealed. But up to date we can simply say that experimental psychological methods have revealed no far-reaching differences in the mental processes of the several races. Even the Igorrote and Negrito deficiency may be due, Woodworth suggests, to their habits of life rather than to their native endowment.

Since exact methods tell us nothing of those higher operations we are most eager to know about, it might be deemed advisable to fall back on general estimates by the most competent observers. Unfortunately, the personal equation enters here to an extent that completely nullifies the value of individual judgments. Travelers in foreign lands are likely to make quite unusual demands on the capacities of the natives with whose aid they are working, and in this way too frequently arrive at an unfair conclusion as to their mental characteristics. In a corresponding test Europeans might do little better. It is, at all events, remarkable that unbiased observers who are fairly sympathetic and remain in long contact with a primitive people usually entertain a rather favorable opinion of their powers. Thus, Prince Maximilian of Wied-Neuwied, expresses the view that, whether other varieties of mankind differ or not, the American aborigines are not inferior to the whites,[2-ii] and corresponding estimates have been made of other races. Still, these are merely personal opinions and we must turn to our second method for possibly more objective, if indirect, evidence on the subject. Are, then, cultural differences necessarily the result of racial differences?

In thus investigating the