Even less reliable are the opinions of speculative biologists who by the use of analogy—that is, by examples of hybridization of plants and animals—try to throw light on the subject of racial intermarriage. In general, the assertions of these biologists agree that the intermixture of races too far apart is undesirable because it results in a breakdown of the inherent characteristics of each, but that the combination of races slightly different is more desirable than intra-racial marriage because it tends to invigorate the stock. To this extent, opinions concur; but as to the question what races may be considered similar and what races different they begin to disagree. Most of them divide the human races by the color of the skin, and state that the case of the black and white races is that of extreme intermixture, and cite that between two white races as a desirable one. When they are pressed to pass a verdict on the result of mixture between the yellow and white races, most of them give only vacillating replies, as in the following extracts:
Yellow-white amalgamation may not be fraught with the evil consequences in the wake of the yellow-black and the white-black crosses. At the same time, it should be pointed out that the Caucasians and the Mongolians are far apart in descent, and that the advantages to be gained by either in this breaking up of superior hereditary complexes developed during an extended past are not clear.[46]
Professor Castle is more precise in his assertion. He says:
Mankind consists of a single species; at least no races exist so distinct that when they are crossed sterile progeny are produced.
Offspring produced by crossing such races do not lack in vigor, size, or reproductive capacity....
Racial crosses, if so conducted as not to interfere with social inheritance, may be expected to produce on the whole intermediates as regards physical and psychic characters.[47]
Here, Professor Castle touches on the important question involved; namely, social inheritance. Indeed, human civilization is not all that is contained in germplasm. Mankind developed and accumulated an elaborate system of living conditions which operate independently of biological processes. However wonderful a brain a child has, he will have to remain a savage if he is born in a savage tribe of Africa or in a place where the level of culture is extremely low. In discussing the possible effect of intermarriage upon progeny, therefore, the cultural level of parents and their environment must first of all be taken into consideration. It is here that we find ground for opposition to intermarriage between Japanese and Americans at present. With some marked exceptions, the cultural standard attained by the mixed couples has on the whole been not of a very high order. This is inevitable when we consider that intermarriage between Japanese and Americans has not yet received full social sanction, thus obstructing free play to the process of natural selection. Aside from the purely biological consideration, this want of social approval of intermarriage, with its concomitant, an unenviable social position of the parents, results in an undesirable environment for the offspring.
The welfare of their progeny is not the only determining point of intermarriage. Is it, then, sufficiently happy for the couple? Our observations lead us to answer in the negative. To be sure, there are cases of fortunate marriages in which it seems impossible for the couple to be happier. But, on the whole, the husband and the wife often find it difficult to harmonize their sentiments and ideals on account of different antecedents. The inharmony seems to grow as the couple advance in age, rendering their lives miserable. The greatest stumbling block, however, seems to be economic. The Japanese in the United States who are engaged in the ordinary walks of life are offered very little opportunities save in farming on a small scale and in petty businesses. Regardless of their ambition or ability, the Japanese cannot get what are considered in America good positions. Hence, neither their positions nor incomes improve very rapidly—perhaps no advance is made. Most American women are not satisfied to follow a blind alley. They turn back and get a divorce. Exceptional cases, of course, are found in the American-Japanese couples, whose husbands have won distinction and wealth by extraordinary personal ability or by scientific or literary attainments, or by representing great firms of Japan.
Our discussion of intermarriage seems to suggest that it is not likely to occur, for some time at least, in large numbers; that as far as hereditary effect on progeny is concerned, it is wholly premature to pass any judgment at present because of our limited knowledge; but that the social as well as the economic position of the contemporary Japanese in America does not seem conducive to the happiness of either the children of such unions or their parents.