Prognathism, or the degree of the protrusion of the jaws, is a conspicuous feature of the profile, and would seem to be of some historic importance as a sign of primitiveness, because all other mammals are more prognathous than man. The trait also has a general correlation with the fundamental racial types. Negroes are almost all prognathous, people of Mongolian type moderately so, Caucasians very slightly. Prognathism is however difficult to measure or to denote in figures. Various apparatuses have been devised without wholly satisfactory results.

The capacity of the skull is measured by filling it with shot or millet seed. The latter yields figures that are lower by 50 or 100 c.c. The average, by shot measure, for males the world over is about 1,450 to 1,500 c.c., for females about 10 per cent lower. European males range from 1,500 to 1,600, Asiatic Mongoloids but little less, American Indians and Polynesians from 1,400 to 1,500, Bushmen, Australians, Tasmanians, Negritos, Veddas from 1,300 to 1,400. These last groups are all small bodied. It appears that cranial capacity is considerably dependent on bodily size. Slender as well as short races run to small capacities. The heavy Bantu surpass the slighter framed Sudanese, and Hindus stand well below European Caucasians; just as the shorter Japanese average less than the Chinese. Broad headed populations show greater cranial capacity than narrow headed ones: Alpine Europeans (§ [24]) generally surpass Nordics in spite of their shorter stature. Individual variability is also unusually great in this measurement. The largest and smallest skulled healthy individuals of the same sex in one population differ sometimes by 500, 600, or 700 c.c., or more than one-third of the racial average. Overlapping between races is accordingly particularly marked in cranial capacity. Furthermore, the measurement obviously cannot be taken on the living. In spite of its interest as an alleged and perhaps partially valid index of mental faculty, cranial capacity is thus of restricted value in distinguishing races.

The texture of the hair is now universally regarded as one of the most valuable criteria for classifying races, possibly the most significant of all. Hair is distinguished as woolly in the Negro, straight in the Mongolian, and wavy or intermediate in the Caucasian. This texture depends principally on the diameters of each individual hair, as they are revealed in cross-section under the microscope; in part also on the degree of straightness or curvature of the root sacs of the hair in the skin. Hair texture seems to run rather rigidly along hereditary racial lines, and to be uninfluenced by factors of age, sex, climate, or nourishment.

Hairiness of the body as a whole is another trait to which more and more attention is coming to be paid. The fullness or scantiness of the beard, and the degree of development of the down which covers the body, are its most conspicuous manifestations. Caucasians are definitely a hairy race, Mongoloids and most Negroids glabrous or smooth-skinned. It is largely on the basis of their hairiness that races like the Australians have been separated from the Negroids, and the Ainus from the Japanese.

Except possibly for stature, color is probably the most conspicuous trait of any race. Under color must be included the complexion of the skin, the color of the hair, and the color of the eyes. All of these however present difficulties to the anthropometrist. The pigment in every human skin is the same: it differs only in amount. We have therefore a complete series of transition shades, and it is difficult to express these differences of shade quantitatively. They readily impress the eye, but it is far from easy to denote them accurately in numbers. Environment also affects skin color markedly. A day’s exposure to the sun will darken an individual’s complexion by several shades. In spite of these drawbacks, however, complexion remains sufficiently important to have to be considered in every classification.

Hair color and eye color are practically immune against direct change by environment. They unquestionably are excellent hereditary criteria, although they offer much the same resistance to measurement as does complexion. The utility of these two traits is however limited by another factor: their narrow distribution. Blue eyes and blond hair are racially characteristic of only a single subrace, that of northern Europe. In central Europe they are already much toned down: the prevailing type here is brunet. In southern Europe, blue eyes and blondness scarcely occur at all except where admixture with northern peoples can be traced. Outside of the Caucasian stock, black hair and black eyes are the universal rule for the human family.

Obviously it would be easiest to arrive at a clear-cut classification by grouping all the peoples of the earth according to a single trait, such as the shape of the nose, or color. But any such classification must be artificial and largely unsound, just because it disregards the majority of traits. The only classification that can claim to rest upon a true or natural basis is one which takes into consideration as many traits as possible, and weights the important more heavily than the unimportant features. If the outcome of such a grouping is to leave some peoples intermediate or of doubtful place in the classification, this result is unfortunate but must be accepted.

Racial Classification of Mankind

Primary Stocks and Races Texture of Hair of Head Hair of Body and Face Head Nose Prognathism Skin Color Stature Remarks
Caucasian or “White”
Nordic Wavy Abundant Narrow Narrow Slight Very “white” Tall Hair blond, eyes light.
Alpine ” ” Broad ” ” White Above aver. Hair brown, eyes brown.
Mediterranean ” ” Narrow ” ” Dark white Medium
Hindu ” ” ” Variable Moderate Brown Above aver. Probable Australoid admixture in South.
Mongoloid or “Yellow”
Mongolian Straight Slight Broad Medium Medium Light brown Below aver. “Mongolian” eye, broad face.
Malaysian ” ” ” ” ” Brown ”
American Indian ” ” Variable ” ” ” Tall to med. Broad face.
Negroid or “Black”
Negro Woolly Slight Narrow Broad Strong “Black” Tall
Melanesian ” ” ” ” ” ” Medium
Dwarf Black ” ” Broad ” Moderate ” Very short Bushmen show several special features.
Of Doubtful Classification
Australian Wavy Abundant Narrow Broad Strong Black Above aver. Negroid traits preponderate, some Caucasian resemblances.
Vedda, Irula, Kolarians, Moi, Senoi, Toala, etc. ” Moderate ” ” Medium Dark brown Short Generalized pre-Caucasian with Australoid resemblances. “Indo Australians.”
Polynesian ” ” Variable Medium ” Brown Tall Perhaps Mongoloid with some Caucasian traits and local Negroid admixture.
Ainu ” Abundant Narrow ” ” Light brown Medium A generalized Caucasian or divergent Mongoloid type.