When it is remembered that whole nations, stocks, races, are characterised by the prevalence of one or other of these skull-forms, it is at once seen that a physical basis is here presented for ethnic psychology worthy of attentive study. These authors have, in fact, applied their conclusions in this direction; but, concerning themselves chiefly with the mixed populations of European states, have been principally occupied with the “social selections” which may be attained in such communities from this cause.
While the skull-form thus becomes distinctive of brains possessing or lacking certain faculties, it must not be supposed that this relation is an essential one. The brain will perform its work without reference to the shape of the skull. This is proved by the many tribes who have artificially deformed the head in obedience to fashion or superstition. In America it is noteworthy that the crania thus malformed to the utmost degree are precisely those of the nations of the highest civilisation—the Mayas of Central America and the Quechuas of Peru.
The Nervous System.—Professor Haeckel, in his lectures on “anthropogeny,” lays down the maxim, “All soul-functions or psychical activities depend directly on the structure and composition of the nervous system.” This is illustrated by the biological development of the nerves of special sense,—of sight, hearing, taste, and smell. Originally they were all indifferent touch-nerves, and by slow degrees in indefinite time developed their specific reactions.
They are yet by no means the same in all persons, as everyone knows. They also differ widely in groups, nations, and races. The study of the “reaction-times” of the principal races has occupied Cattell, Bache, and other psychologists. The sense of taste is notably different. An Eskimo finds pleasure in castor oil and a Kamchatkan in eating rotten fish. The Annamite is almost insensible to pain from wounds, but suffers intensely from moderate cold and is acutely affected by odours. The Fuegian can sleep naked on the snow with comfort, but is easily disturbed by noises.
The intellectual differences between both individuals and races arise not so much from relative mental capacity as from varying reaction to mental stimuli. They all have pretty much the same power to pursue knowledge, if they choose to exert it. The difference is one involving the general nerve-tracts. Perception and attention were the forces which in the history of organisms developed all the special senses from nerves of touch; and the growth of the intellect is consequently closely conditioned by the qualities of nerve-sensations.
The Osseous System.—To be asked to define the ethnic life of a group from the bones exhumed in its cemeteries would seem a hopeless task. Yet it is possible, for on the osseous system the whole bodily structure is built up, and the activity of the brain is conditioned.
Races differ in their skeletons. That of the African black is heavy, the flat bones thick, the pelvis narrow, and presents many peculiarities which are termed “pithecoid” or ape-like. Contrasting with these are small-boned, delicately formed skeletons of the Indonesians and Japanese, resembling those of the female in other stocks. It would not be difficult to bring the ethnic into relation to these skeletal traits.
Professor Hervé, of the School of Anthropology of Paris, has argued that the presence of the “Wormian bones” and the complexity of the cranial sutures are a measure of the rapidity of brain-development, and consequently a criterion of mental activity in a stock. This can scarcely be accepted, for we are not sure that the rapidity of bone-formation bears any ratio to the growth of the brain-cells; but it is not rash to argue that a people whose bones are largely diseased must have lived in unhygienic conditions, and had become degenerate in mind as well as body.
Such is the case with the skeletons of that wholly unknown tribe who once densely peopled the Salt River valley in Arizona, and of those who dwelt near the great cemetery of Ancon in Peru. About one-third of the skeletons present pathological features indicating long-continued defective nutrition or widespread disease. No wonder that both stocks perished off the earth. Though at one time singularly advanced, they had sunk into complete degeneracy.
Muscular System; Height and Weight.—There is a relation between height, weight, and mental power, true for the individual and the group. This is not mysterious, as all three depend upon nutrition. Physiologists lay down ratios of height, weight, and age which are requisite to the highest health, mental and physical.