Page:Popular Science Monthly Volume 71.djvu/85

Rh tendency more often than to failure to find opportunity to marry. Sexual selection is probably still of some importance in man, though of problematic influence.

Reproductive selection is by far the most important of selective instrimientalities operating in civilized man. Here, and very recently, it has first come to great importance. One sixth and more of marriages in certain portions of civilized society are infertile. And differences in the number of children to a family are still more significant. This absolute or relative infertility must be more or less selective in its incidence. Nerve-racking indulgences and ambitions suggested or elicited by civilized life seem to create physiological conditions unfavorable to reproduction. Still more important is the fact that, with the increase and spread of physiological knowledge, the size of the family is placed under the control of volition, and children are no longer a necessary or to be expected result of sexual gratification. So the wish not to be bothered with children, with the moral traits it implies, leads to elimination. Over-cautiousness and desire to pamper children, on the other hand, resulting in the so-called "two-child system," bring about, though more slowly, the same result. The overcautious in such matters certainly will not "inherit the earth." Conscientiousness on account of transmitting physical weaknesses acts in the same way. Celibacy as a religious observance has probably taken from society some of its gentlest natures.

An average of nearly four children to a family is necessary to keep up the numbers of a population. For a family to have fewer is likely to mean that it will have less representation in the next generation than in the present. Such a family is certainly not holding its own in a country of increasing population like the United States. Hence the plaint of "race suicide," which is in fact never race suicide, but only the self-elimination of a particular section of society. The blood of France may become Breton, but it not at all likely that France will lose its population. The New England stock, which populated the West, is probably now declining in numbers in its old home by deficiency of natural increase. But New England is gaining population. There are always relatively and absolutely fertile elements in society, as well as the relatively infertile. The significant thing is what are their differences as regards mental and moral traits. Is "race suicide" due more to selfishness or to over-caution? Is high fertility due more to improvidence or to the love of children? How far is a high standard of life associated with the most desirable mental traits?