Note 45 — Chapter V

Morgan’s theory of exogamy. 11. Next comes that advocated by Mr. Morgan45 and others, that it arises from the recognition of the observed evils of intermarriage between near relations. This theory has been with some slight modifications accepted by Dr. Westermarck46 and Mr. Risley.47 Briefly put, it comes to this: No theory of exogamy can be satisfactorily based on any conscious recognition by the savage of the evils of interbreeding. Of all the instincts of primitive man the erotic are the most imperious and the least under control. To suppose that a man in this stage of culture calmly discusses the question whether his offspring from a woman of his group are likely to be weaklings is preposterous. But the adoption of marriage outside the group would, in the end, by the process of natural selection, give the group practising it a decided physical advantage. As Mr. Risley puts it:—“As a result of the survival of the fittest the crossed families would tend more and more to replace the pure families, and would at the same time tend to become more and more exogamic in habits, simply as the result of the cumulative hereditary strengthening of the original instinct. It would further appear that the element of sexual selection might also be brought into play, as an exogamous family or group would have a larger range of selection than an endogamous one, and would thus get better women, who again, in the course of the primitive struggle for wives, would be appropriated by the strongest and most warlike man.”