Introduction to the Science of Sociology

by Robert Ezra Park; E. W. Burgess

It will be seen that on the answers to such questions depends the destiny of races and the consequences to the species of the facilities of transportation offered by modern inventions. The subject has therefore received the careful study of medical geographers and statisticians.

I can give but a brief statement of their conclusions. They are to the effect, first, that when the migration takes place along approximately the same isothermal lines, the changes in the system are slight; but as the mean annual temperature rises, the body becomes increasingly unable to resist its deleterious action until a difference of 18° F. is reached, at which continued existence of the more northern races becomes impossible. They suffer from a chemical change in the condition of the blood cells, leading to anemia in the individual and to extinction of the lineage in the third generation.

This is the general law of the relation to race and climate. Like most laws it has its exceptions, depending on special conditions. A stock which has long been accustomed to change of climate adapts itself to any with greater facility. This explains the singular readiness of the Jews to settle and flourish in all zones. For a similar reason a people who at home are accustomed to a climate of wide and sudden changes, like that of the eastern United States, supports others with less loss of power than the average.

A locality may be extremely hot but unusually free from other malefic influences, being dry with regular and moderate winds, and well drained, such as certain areas between the Red Sea and the Nile, which are also quite salubrious.

Finally, certain individuals and certain families, owing to some fortunate power of resistance which we cannot explain, acclimate successfully where their companions perish. Most of the instances of alleged successful acclimatization of Europeans in the tropics are due to such exceptions, the far greater number of the victims being left out of the count.

If these alleged successful cases, or that of the Jews or Arabs, be closely examined, it will almost surely be discovered that another physiological element has been active in bringing about acclimatization, and that is the mingling of blood with the native race. In the American tropics the Spaniards have survived for four centuries; but how many of the Ladinos can truthfully claim an unmixed descent? In Guatemala, for example, says a close observer, not any. The Jews of the Malabar coast have actually become black, and so has also in Africa many an Arab claiming direct descent from the Prophet himself.

But along with this process of adaptation by amalgamation comes unquestionably a lowering of the mental vitality of the higher race. That is the price it has to pay for the privilege of survival under the new conditions. But, in conformity to the principles already laid down as accepted by all anthropologists, such a lowering must correspond to a degeneration in the highest grades of structure, the brain cells.

We are forced, therefore, to reach the decision that the human species attains its highest development only under moderate conditions of heat, such as prevail in the temperate zones (an annual mean of 8°-12° C.); and the more startling conclusion that the races now native to the polar and tropical areas are distinctly pathological, are types of degeneracy, having forfeited their highest physiological elements in order to purchase immunity from the unfavorable climatic conditions to which they are subject. We must agree with a French writer, that "man is not cosmopolitan," and if he insists on becoming a "citizen of the world" he is taxed heavily in his best estate for his presumption.

The inferences in racial psychology which follow this opinion are too evident to require detailed mention. Natural selection has fitted the Eskimo and the Sudanese for their respective abodes, but it has been by the process of regressive evolution; progressive evolution in man has confined itself to less extreme climatic areas.

The facts of acclimatization stand in close connection with another doctrine in anthropology which is interesting for my theme, that of "ethno-geographic provinces." Alexander von Humboldt seems to have been the first to give expression to this system of human grouping, and it has been diligently cultivated by his disciple, Professor Bastian. It rests upon the application to the human species of two general principles recognized as true in zoölogy and botany. The one is that every organism is directly dependent on its environment (the milieu), action and reaction going on constantly between them; the other is, that no two faunal or floral regions are of equal rank in their capacity for the development of a given type of organism.