# Personal Beauty and Racial Betterment/Incest and Inbreeding

In all stages of society there have been developed restrictions on mating which are conveniently described as incest-prohibitions. The wide variations in the tabus or conventions of this sort have given rise to much discussion among anthropologists and sociologists, but the universal principle on which these tabus are based is now quite clear. Whether the prohibition is against the mating of blood-relations of certain degrees, or against mating of persons socially related through
​common name, or totem, or tribal subdivision, it is always of such a nature as to prevent the conjugation of persons who are reared in close assocation or intimacy; causing the individual to look for a sex-mate beyond the limits of his immediate “family.” In many cases, the prohibition is retained long after the “family” life is so changed that the original reason has ceased to exist; as for example, is the case with the prohibition of the marriage of first cousins, who in many communities are no longer apt to be reared in greater intimacy than are children not blood-related at all. This persistence of conventions no longer useful is so common in society generally as to raise no special difficulties in understanding the incest prohibitions. In origin, these prohibitions are, without exception, conventions against the sex-mating of what may be designated as “house-mates.”
The importance of incest-conventions needs no argumentative support. The sex-impulse, in spite of its strength, is easily directed by conventions: the assumption that such and such persons are not possible sex-mates, if inculcated early enough, is a very efficient preventive of sex-interest in those persons. Without such conventions, the probability of the too early maturation and excessive development of the sex-instinct is very great. Incest-prohibitions must therefore be religiously, if ​not blindly, preserved, if the future of the race is to be guarded.
Inbreeding, which is frequently confused with incest, is a radically different matter, although in particular cases the two conditions may overlap. The union of cousins is inbreeding, and may be incest, but the reasons for prohibiting it as incest have nothing to do with the biological results of the inbreeding. The popular notion that the incest-convention has grown up as a result of observation of the evil effects of inbreeding, or through an “unconscious” knowledge of such evil effects is entirely fallacious. The justification, moreover, of an outworn incest-convention of this sort, through an appeal to the supposed evil effects of inbreeding, is without proper foundation.
It is now well known that inbreeding has in itself no evil effects. Stocks do not deteriorate through consanguineous marriages, but strong points as well as points of weakness are accentuated. Feeble-mindedness furnishes a good illustration of the results of breeding. Some of the progeny of the union of a sound and a feeble-minded parent, will be sound: but they carry in their germ-cells the “determinant” of feeble-mindedness, and transmit it to a certain proportion of their own progeny. If two persons, both of whom carry this determinant, mate, the ​characteristic will reappear in certain of their progeny (that is, some of their children will be feeble-minded) although the characteristic may have been latent for several generations. Obviously, parents who both come from feeble-minded stock are more apt to possess this determinant than parents of diverse stock: hence we see the feeble-mindedness reappearing strikingly in certain cases of consanguineous marriages. The situation with regard to other weaknesses is similar. Marriage of cousins produces a significant number of deaf, or color-blind, or otherwise defective children because these defects were latent in the stock and are brought out by being transmitted through both parents. If the parents in such a case had each married persons not carrying the “determinant” of the defect in question, the defect might not have appeared, but (and this is the consideration which must not be forgotten), the determinant would have been transmitted to a certain proportion of their progeny, to reappear or produce the defect, in later generations when the conditions were favorable.
With regard to points of strength, the situation is the same as with points of weakness. High intelligence and longevity are actualized in the progeny of parents who both possess the determinant, whereas the determinant is in a large ​proportion of cases merely carried over to later generations if only one parent possesses it.
Instead of inbreeding being a racial evil, it may be a distinctly valuable means of progress. Strong strains are thereby conserved, and weaknesses in other strains are brought to the surface, so that they may be recognized and eliminated. This consideration applies not only to inbreeding, but the general mating of like with like, for the results of conjugation are the same when two persons who mate both possess the same determinant, whether these persons are closely or remotely related in blood. If feeble-minded mate with feeble-minded; if those who carry the determinant but do not show it, mate only with those who also carry the determinant, a large proportion of feeble-minded children will result from these unions. These children may then be institutionalized (if not sterilized) and prevented from reproducing, and their heredity thus eliminated. If, on the other hand, those of feeble-minded heredity mate largely with those of better heredity, the determinant is passed on, to make trouble in a larger degree in future generations, when like mates by chance with like.
For the welfare of the race therefore, like should be encouraged to mate with like, especially in so far as weaknesses are concerned, and inbreeding, in so far as there is no encouragement of
​incest, should have the ban against it removed. However unwise the removal, in England, of the prohibition against marrying a deceased wife’s sister, may have been—because she is so frequently a husband’s housemate—there is little reason, in America, in discouraging the marriage of first cousins. In the cases of aunt and nephew, and of uncle and niece, the incest-relation is possibly a distinct consideration.