The desirability of selecting a wife (or husband) from a family of more than one or two children was emphasized by Benjamin Franklin, and is also one of the time-honored traditions of the Arabs, who have always looked at eugenics in a very practical, if somewhat cold-blooded way. It has two advantages: in the first place, one can get a better idea of what the individual really is, by examining sisters and brothers; and in the second place, there will be less danger of a childless marriage, since it is already proved that the individual comes of a fertile stock. Francis Galton showed clearly the havoc wrought in the English peerage, by marriages with heiresses (an heiress there being nearly always an only child). Such women were childless in a much larger proportion than ordinary women.
"Marrying a man to reform him" is a speculation in which many women have indulged and usually—it may be said without fear of contradiction—with unfortunate results. It is always likely that she will fail to reform him; it is certain that she can not reform his germ-plasm. Psychologists agree that the character of a man or woman undergoes little radical change after the age of 25; and the eugenist knows that it is largely determined, potentially, when the individual is born. It is, therefore, in most cases the height of folly to select a partner with any marked undesirable trait, with the idea that it will change after a few years.
All these suggestions have in general been directed at the young man or woman, but it is admitted that if they reach their target at all, it is likely to be by an indirect route. No rules or devices can take the place, in influencing sexual selection, of that lofty and rational ideal of marriage which must be brought about by the uplifting of public opinion. It is difficult to bring under the control of reason a subject that has so long been left to caprice and impulse; yet much can unquestionably be done, in an age of growing social responsibility, to put marriage in a truer perspective. Much is already being done, but not in every case of change is the future biological welfare of the race sufficiently borne in mind. The