Page:Popular Science Monthly Volume 71.djvu/84

78 for that is great indeed. Modern improvements in medicine and surgery may check the incisiveness of such action of selection. But they can only lower, not destroy, the standard set for survival. Lethal selection, however, even as regards mere physical qualities, amounts to much less for Occidental civilized man than for any other species of living thing. But some other species of selection are proportionately more important.

A weightier consideration that might appear to make lethal selection of less interest to the sociologist is the fact that it appears hardly to touch what is distinctively human in man's constitution, that is, his mental and moral qualities. But such selection does in fact promote mental stability, so far as the strain and stress of modern life drive men to insanity and death. Alcoholism, too, as is proved by the experience of life insurance companies, and by statistics of occupational mortality, tends to eliminate those who are in this respect deficient in self-control. In various ways the ignorant, the imprudent, and the vicious, tend to destroy themselves.

The effects of sexual selection are much more deeply marked in the organisms of birds than among mammals. The sexes in civilized man, however, show pretty clearly its differentiating influence. The greater strength of the male in man is probably due in part to sexual rivalry. As regards women, on the other hand, their conventional title, the "fair sex," is probably due to something more than mere chivalry or mere flattery. The pretty girl still marries better or earlier than her less "well-favored" sister. It is to be hoped that more important qualities than personal appearance are also favored by sexual selection.

Alfred Russel Wallace, the co-discoverer with Darwin of natural selection, though he curiously enough grudges recognition of it as a factor in the evolution of lower animals, apparently because it involves rather highly developed mentality, sees in esthetic sexual selection on the part of women the great means to the future progress of the human species. With this opinion, the writer can not agree. Marriage is not so much a result of exclusive and exacting "elective affinities" that the relatively ineligible can not solace themselves with those of the other sex who are similarly situated. The approximate equality of sex numbers and the institution of monogamy, which forestalls monopolizing tendencies, leave no considerable class of persons eliminated by lack of opportunity to marry. Postponement of marriage on this account is probably of some influence, but of no great importance. Postponement of marriage and abstinence from it—the latter amounting to more than one fifth in some regions—are probably due to variation in the relative strength of the marital and