Before proceeding to a detailed historical survey or to technical matters, it seems advisable to state at greater length than in the preceding section some of the principles which we believe to govern the formation of human races. First of all the question arises, "What is a race?" and the problem of this definition must be squarely faced. In the course of the present study the author has developed a definite point of view on this subject, which may be expressed as follows: The concept race is a general one, and any attempt to chain it down to a more specific meaning represents a too rigid attempt at taxonomy. The use, under strict definition, of such convenient words as sub-race, stock, variety, local type, etc., implies a Linnaean classification of categories which is foreign to the facts of human biological differentiation.

One may, in a group of animals such as man, definitely name and classify the major group to which all individuals belong. All living varieties of human beings are mutually fertile, and there is no other animal with which man may be crossed. Although the fertility test is not necessarily a diagnostic, Homo sapiens in the living sense comprises, without question, a species, even if in the formation of the living human group more than one related species, now extinct in the pure form, was absorbed.²

So much for the larger group. Within this larger group there are many variations of superficially great importance. There are pygmy men whose mean stature is less than 150 cm. There are giant-like men whose mean stature is over 180 cm. At the same time there ate black men and white men; men with kinky hair, men with straight hair; men with beards and without; and so on. Their variation is much greater than that found among wolves, or among tigers, or among any one species of mice. Yet it is not as great as the variation found among dogs, who again form a single species, and who in turn may include a blend of two - wolf and jackal.

Here again, we must repeat, man is a domestic animal, and as such is subject to the laws which govern animals in domestication. Being less dependent in a direct sense upon a given environment than a wild animal, he is much more variable; having become numerous as a result of this partial emancipation, he has spread into many environments, so that what influences these environments have had upon him have been extremely varied. At the same time the laws which govern his mating are different from those which govern the conjunction of wild animals. Furthermore there has been some degree of selection in this mating, but less than the selection which has so profoundly differentiated the dog.

All of the principles mentioned above have produced, as their effect, a prodigious differentiation within the human species, and one which must at times have proceeded with startling rapidity. At the same time there has taken place an almost equally great mixing and blending of peoples, under circumstances that could hardly occur among wild animals. For example, the mixture between whites and negroes has most frequently involved white men and negro women, and only occasionally the reverse. Within the ranks of mixture, there has often been a selection on the basis of differential social values attached to different combinations of characters. As a result of all these factors, one must not suppose that a racial classification of man into a simple and orderly scheme can be easy.

We have already recognized the concept species in regard to man. There is one other concept, wholly theoretical for practical reasons, which may be recognized with equal definition. That is the pure strain, the result of generations of inbreeding and selection of recessive characters. In man, the pure strain is impossible to create unless our social system radically changes. In rats, guinea pigs, and fruit flies, it has been created. From rats, guinea pigs, and fruit flies, biologists slowly and painstakingly discover the laws which govern inheritance. They almost unanimously favor the Mendelian form, and there can be little doubt that Mendelism also applies to man. But man is a genetically complex animal, and we do not, apparently, measure characters which are Mendelian units. If we were to measure the right things, we would theoretically find that Mendel's Law is always applicable. The principle of inheritance through blending, by which is derived the formula

depends upon a multiplicity of compensating Mendelian characters. That these are not always multiple, or that they do not always compensate, is shown by certain instances in which blending has not resulted from mixture.

For example, the height of the cranial vault and the heights of the face and nose often fail to respond in the expected manner. Negro-white hybrids in the United States have long faces and noses,³ and so do Ethiopians⁴ Pitcairn Islanders have more convex noses than do either English or Tahitians.⁵ Other instances have been found in which human inheritance has failed to assume the character of a blend. These serve merely as examples. Mixture alone, however, cannot create and perpetuate a new racial form, although it can produce new combinations. Mixture when combined with selection, to emphasize the new and eliminate the old, can, however, produce a decisive change.⁶

In view of the complexity of the human species, as a result of its cultural peculiarities which have separated it from the rest of the animal world, it is not easy to define the word "race." Since man is the oldest domestic animal, his variation and selection have operated over an immensely longer span of time than those of the other species for whose present forms he is responsible. Any attempt to classify him by a rigid scheme is immensely difficult, and the scheme must be elastic if it is to work at all. Hence the term "race" must also be elastic. We may recognize, if we like, certain major races of the Old World such as the Khoi-San (Bushman-Hottentot), the Pygmy, the Australoid, the Negro, the Mongoloid, and the White. Within each of these major racial groups there are, or have been, smaller entities which may deserve the designation of race in a lesser sense. These smaller entities consist, for the most part, of groups of people reasonably isolated, and developing into local physical enclaves by the three processes, usually linked, of amalgamation, selection, and environmental (in the total sense, including cultural) response. At what borderline point such an entity becomes a major race, it is not always possible to say.

Let us consider these three forces - amalgamation, selection, and environmental response. We have already mentioned the first, which is more commonly called race mixture. We have already observed that while blending seems to be the usual result, in some criteria there is evidence of simple Mendelism or the heaping of dominants or recessives. Amalgamation, furthermore, can produce a differential dominance based on age grading; for example, the dominance of hair blondism in infancy, coupled with the darkening of the hair in adolescence and adult life, link blondism with infantile characters. The same is not true of eye blondism, which grows slightly more pronounced with age. At the same time mongoloid morphological characters are more pronounced in infantile hybrids than in the adults; the reverse is true of most distinctively white features in combination with those of either negroids or mongoloids. This differential age dominance is, except in the case of blondism, an heritable endocrine function connected with the relative degree of infantilism associated with each of the major racial groups.

Selection is a difficult force to study in man, at least in a scientific sense. But it is without question one of great importance. Sexual selection probably has and always has had a certain application, which may be seen in the current standards of beauty in different countries. The standards of one group may be shifted through the cultural medium to another. But since in any population other than an industrial, civilized one there are few bachelors and few spinsters, sexual selection must have worked slowly in most cases, at least in the sense of an eliminative rather than a segregative principle. Warfare, again, kills off a selected group of males, while celibacy connected with the assumption of religious offices may render genetically ineffective a selected population element.

The most important selection is probably that consequent on changes of environment, by which the selective factor may perhaps be a physiological economy in response to new types of mineral deficiency. This type of selection may have been of profound importance in the evolution of man as a species, as well as of different races.⁷ Small, foetalized, relatively weak races may be more efficient and hence more suitable for survival in certain environments than larger, more muscular, and less infantile ones. Small, foetalized, and relatively defenseless mammals develop elaborate social devices by which the solidarity of the group compensates for the deficiency in individual aggressiveness; man on the whole is a social animal comparable in this respect to the Cebus monkey. The type of environmental selection postulated by Marett may have been of profound im-portance in the evolution of man as a species, as well as of different races.

Another form of selection is intimately concerned with the complexity of the social structure. When a population is stratified into social horizons, this cultural differentiation is often the result of the conjunction of two or more social and hence ethnic groups, from two or more geographical sources. It takes time for cultures to blend and for people who practice these cultures to mix, and if there exists, at the same time, the idea that one group is superordinate and the other subordinate in social values, the social mechanism will often function in such a way as to perpetuate this cleavage. Thus the mixing process will be retarded, and at the same time a difference in the reproductive rates of the two racially identified social horizons may arise.

As a rule, at least in modern times, the group which is considered subordinate will reproduce with greater fecundity than will the superior class. In this way the upper class will gradually disappear, or else social mobility will gradually replace the upper from the ranks of the lower, and the social distinction will remain, but without racial significance. Thus a differential reproductive rate has, in effect, a selective value, and one population may quietly replace another. Whether or not the replacement is complete, the relative numerical importance of the two genetic strains will have been altered.

Extreme differences in skin color, in body odor, and in face form are more active deterrents to such mobility than are differences important to the anthropologist but not to the public, such as the cephalic index and other measures of head form. Differences of the first class prevent the American Negro from complete absorption into the ranks of the white, for his diagnostic racial characters, unless the negroid factor in the individual inheritance is dilute, are easily noticeable. On the other hand differences in head form are not usually noticed, and a brachycephalic white population may replace a dolichocephalic one by means of social mobility.

So far we have been considering selection within a geographically immobile group, or rather, selection at the geographical point under consideration. But there is still another type of selection which is very important, and that is mobile selection, operating at the point of emigration, the source of population supply. We shall see, in our survey of prehistoric European racial movements,⁸ that the Danubian agriculturalists of the Early Neolithic brought a food-producing economy into central Europe front the East. They perpetuated in the new European setting a physical type which was later supplanted in their original home. Several centuries later the Corded people, in the same way, came from southern Russia - but there we first find them intermingled with other peoples, and the cultural factors which we think of as distinctively Corded are included in a larger cultural equipment. The Corded people, therefore, who left southern Russia and moved westward into central and northwestern Europe, were a selected group of people, chosen from a larger and more heterogeneous human storehouse. This situation clearly involves the principle that people who migrate from an old home to a new do not represent, in most cases, the total or typical physical form of the home land, provided that the new home is different from the old; but they represent a special group selected on the basis of their suitability and opportunity for migrating. This principle can be clearly seen in the study of modern migrating peoples.

The Poles who came to the United States during the nineteenth century, and the early decades of the twentieth, did not represent a cross-section of the Polish population, ⁹ but a taller, blonder, longer-headed group than the Poles as a whole. In other words, there was a definite selection of a special physical type which influenced some Poles to come to America and others to stay at home. Dr. Shapiro has found that the Japanese who migrated to the Hawaiian Islands are significantly different in many metrical and morphological characters from their own relatives who remained at home¹⁰ This was determined not by a study of representative samples, but by the actual measurement of relatives, in Hawaii and Japan.

In the same sense, the Americans of colonial British ancestry are not like Englishmen in the larger sense of the word. The English who went to America in the Colonial period were a definitely selected group - selected on the basis of religion, social and economic position, and geographical distribution. Once in America, under new conditions, comparative isolation, and the intensive cross-breeding of relatively few family lines, this differentiation was accentuated. Once the arable lands of New England and New York State had been cleared and cultivated, the farmers who moved westward into the fertile Ohio Valley, and on successively to Indiana, Illinois, and Iowa, were not typical examples of the total population of which they were drawn. The selection of the mountain men of the Rockies, and of the early cattle rangers of the Plains was even more noticeable.

So far we have been considering selection in migration in reference to the new country settled by the immigrants, but this selection, when the migration occurs in any numbers, has an equally important racial effect upon the old country. The depopulation of Ireland and Sweden through emigration to America must have affected the racial constitutions of these countries, just as the mass exodus of several hundreds of thousands of Germanic tribesmen in the Völkerwanderung period must also have affected northern Germany and Scandinavia.

A lesser selection in scope, but equally important in principle and in effect, is the selection of urban populations from rural sources. Numerous European studies have made it clear that the young men and women who leave their villages to seek a new manner of living in the cities are racially atypical of the village populations as a whole, and that the drainage of these people from the fecund rural districts into the relatively fertile cities has a selective value in the determination of the physical nature of the rural population.¹¹

Selective differences in emigration and immigration exist in the cultural as well as in the racial sense. The Corded invaders who moved westward into Europe did not carry all the trappings of Asiatic and south Russian culture with them; they took only those objects which they would find useful in their new environment, and easy to replace from local materials. In the same way the early American plainsman and trapper did not till his knapsack with lace sleeves, wine glasses, and silver shoe buckles, but carried only such clothing, weapons, and other equipment which he knew would be of service to him. Later on, after he had settled the new country, the more luxurious trappings of the old culture could follow, provided that he had maintained contact with his original home.

This last principle again applies to race as much as to culture. The settlers who come to a new country later, after the ground has been explored, are often drawn from a different segment of the original society, and may represent a different racial entity, with different cultural associations and aptitudes from that of the pioneers.

Having dealt with amalgamation and selection, there remains the principle of environmental response. That human evolution has been going on ever tzce the initial acquisition of the distinctive human traits, such as speech, the use of fire, and the making of tools, cannot be denied. Man did not stop evolving once he became a man. We have seen that Pleistocene man, of whatever type, was more primitive in some respects than modern civilized man. The reduction of face size, and especially of the masticatory apparatus, is, for example, one of the most marked and most widespread active human evolutionary trends.¹²

There are other responses, however, which are not necessarily evolutionary, but which must be considered direct reactions to environmental change, in a broad sense. Changes in type and complexity of civilization, acting presumably through nutritional agencies, may serve as environmental stimuli and produce somatic effects. These responses, as observed in modern times, take the form of sweeping trends. The increase in stature which has affected northern and western Europe and much of the New World so profoundly within the last century is lust such a trend. That it is a true mass response and not merely a selective process is shown by Bowles's studies of three generations of Harvard freshmen, taking only actual genetic lines of grandfathers, fathers, and sons.¹³ That it is culturally motioned, whatever the mechanism, cannot be denied, for it is found only in countries which have been modernized progressively and thoroughly during this period.

The most striking modern stature increase must be that of the English colonists in Queensland, for which there is ample evidence but no available scientific data. The Queenslanders have shot up to an immense height, uniformly and with few exceptions, and have acquired a lanky, leptosome bodily habitus. Since the Queenslanders are essentially pioneers, living largely off the soil, this must be due to direct environmental stimulation in the geographical sense.

Stature increases may be matched with equally marked decreases. During the Dark Ages, from the time of colonization to the sixteenth century, the Icelanders, originally as tall as their Norwegian ancestors, shrank in stature to the size of southern Italians.¹⁴ Climatologists now tell us that this shrinking accompanied a lowering of mean annual temperature, and an increased dampness.¹⁵ Icelandic history adds that it was a period of near starvation. The Greenlanders, who suffered even more from this climatic change, became even smaller than the Icelanders before their extinction.¹⁶ Yet the Ieelanders who survived this depression grew rapidly once it was over, until at present they comprise one of the tallest groups in europe. The population of Iceland has not been materially added to by migration since the initial settlement.

One of the best examples of environmentally conditioned physical stunting is to be seen in the misery area of the Limousin hills in central France.¹⁷ Here isolation, poverty, and the dependence on the produce of an infertile granitic soil seem without reasonable doubt to have been the contributing causes. Mineral deficiency, in the sense in which Marett uses it, may be invoked, as well as malnutrition. Another example of environmental conditioning may be seen in the common level of short stature, for the most part below 160 cm., which extends in a circumpolar zone around the world. If environment can so demonstrably affect stature, and act with such rapidity (the New Englanders have grown 7 cm. in 100 years), then it is more than likely that it can affect other racial criteria, including head form. The excessive brachycephalization which swept over central Europe in the Middle Ages, affecting especially southern Germany and Bohemia, followed the same pattern as the stature change. Both proceeded as orderly increases at fixed rates of speed. Selection may have been a large contributing cause, through infiltration and differential birth rates. Simple Mendelian dominance of brachycephaly, which has never been demonstrated, may not be eliminated, but it cannot have been the only factor involved. But even if we grant infiltration and differential selection and direct Mendelism, it is difficult to account for the rise in cephalic index in the south German and Alpine region over any level which it had attained in antiquity, historic or prehistoric, unless we place this change at least partly on the basis of a response to environmental stimuli. The food-gatherers of west-central Europe seem to have respnded to an earlier and equally extensive brachycephalization during the Mesolitbic, a period of profound climatic change; and the parallel modification, millennia later, among civilized food-producers, may, for reasons as yet unknown, have followed a parallel mechanism of change.

All of this leads us back eventually to where we started, when we began to consider the meaning of the word race. A race is, in view of this discussion, a group of people who possess the majority of their physical characteristics in common. A pure race, if the term need be used, is one in which the several contributing elements have become so completely blended that correlations fail to reveal their original combinations.¹⁸ At the same time the processes of selection and of response to environmental influences have given the resultant blend a distinctive character.

The longer such a human entity remains isolated, the more distinctive it may become in the racial sense. It may expand numerically, divide, and become a major human stock, while others once much more numerous may become almost extinct, or fully so through absorption. But the most important fact about a race is that it is an entity, however ill defined, which is never static, but always in process of change.

If, as above, we define race as a group of people reasonably unified in the physical sense and living in one place, difficulties at once arise. How are we to draw the borderline between that place and the next? Where does one race leave off and the next begin? There are those who assert that a race is merely an artificially assumed point on the smooth and glassy surface of a geographical continuum,¹⁹ for what may be the concentration point for an extreme condition in one criterion will be an intermediate point in others. This assertion is, to a certain extent, true. If we view the panorama of living races on a two dimensional map, we can but agree that a race in this sense is merely a reasonably homogeneous group of people who occupy a given arbitrary point upon a terrestrial continuum. In regions of geographical smoothness one condition blends broadly and gently into another; in regions cut up by geographical barriers, such as deserts or mountains, the contrasts are sharper and the transitions more rapid.

As long as we confine our glance to the surface, we will continue to be faced with this dilemma. But a solution comes with the application of a third dimension, that of history. By means of an historical reconstruction, with numerically adequate and competently documented skeletal material, it should be possible to determine what has happened in most regions occupied by the white race; why present conditions obtain; and what is a suitable classification of existing races, built upon the dual basis of the past and present.

This classification must, of course, meet existing conditions and not be an expression of history alone, or of national ideals. By means of such a classification we may hope to answer the continuum objection, and show which spots on the map do actually represent centers of racial dissemination and which have functioned more characteristically as zones of intermediacy and blending. in accordance with principles which are now beginning to be understood.²⁰

But we must remember, at the same time, that zones of intermediacy and blending may change their function without warning and assume the rôle of feeders of racial material to other regions. The interplay of these functions, in accordance with the principles already detailed in this chapter, has produced the racial complexity which characterizes most of the earth, and especially those portions occupied by the more active and vigor-ous and numerous branches of man, the Negroids, the Mongoloids, and the Whites.

Notes:

2 See Chapter II, section 5.

3 Hooton, E. A., HAS, vol. X, part II, 1932, pp. 42-107.

4 Unpublished data in author's possession.

5 Shapiro, H. L., The Heritage of the Bounty, pp. 229-233.

6 Baur, Fischer, and Lenz, Human Heredity, p. 176.

7 Marett, J. R. de la H., Race, Sex, and Environment.

8 Chapter IV.

9 Rosinski, B., PAn, vol. 8, 1934, pp. 42-44.

10 Shapiro, H. L., SM, vol. 45, 1937, pp. 109-118; also, Migration and Environment.

11 Bryn and Schreiner, Somatologie der Norweger, pp. 342-344, will serve as an example.

12 Ashley-Montagu, M. F., QRB, vol. 10, 1935, pp. 32-59.

13 Bowles, Gordon T., New Types of Old Americans at Harvard.

14 Seltzer, C. &, unpublished MS. in Peabody Museum. Author's permission.

15 Brooks, C. E. P., QRMS, vol. 47, 1921, pp. 173-1 90.

16 Hansen, Fr. C. C., MOG, vol. 67, 1924, pp. 291-547.

17 Ripley, W. Z., Races of Europe, pp. 168-171, after Collignon, R., MSAP, scr. 3, vol. 1, 1894, pp. 3-79.
Collignon, R., AG, vol. 5, 1896, pp. 156-166.

18 Scheidt, W., ZFMA, vol. 27, pp. 94-116.

19 I am indebted for this concept to Dr. George Woodbury.

20 Keiter, F., ZFRK, vol. 3, 1936, pp. 40-46.