mon 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
