The evidence that these children have greater powers of application, or at least that some of them do, lies in the birthdays of eminent people in countries as diverse as India, Spain, Russia, England, France, Germany, Sweden, and the United States. In all these countries the percentage of eminent people conceived when the optimum weather prevails rises much higher than does the corresponding percentage among ordinary people. Moreover, the greater the degree of eminence, the more marked is the contrast with people as a whole.
The reason for this condition must be that the vigor which gives to many people long life gives to highly gifted people a sort of power of steady application and hard work—an emotional stability—which enables them to use their faculties to the best advantage. Thus they achieve fame in greater measure than do equally well-endowed persons with less vigor. There is not the slightest reason to suppose that children conceived at one season of the year inherit any better minds than do their brothers and sisters conceived at other seasons. There is equally little reason to believe that the average inheritance of mental ability declines as the period of conception approaches midwinter, the low point in the seasonal cycle of reproduction. On the other hand, length of life furnishes evidence that physical vigor varies according to the degree to which the mothers at least, at the time of a child's conception, have been under the influence of environmental conditions which assist the germ cells in developing into vigorous babies. Many studies of eminent people show that they are uncommonly long-lived. When deaths in war and by accident are omitted, the average length of life of 11,000 people in the British Dictionary of National Biography was 71 years. Eminence and the kind of constitutional vigor that leads to long life go together.
This brings us back to the problem of fitness for marriage. If the effect of the weather on the vigor of parents can have such an influence on health, longevity and achievement, such conditions as diet and mode of life may produce similar effects. This possibility adds still greater interest to the two-edged bearing of what we have just been saying upon the problem of fitness for marriage. In the first place it appears that an unexpected number of weaknesses which are sometimes considered hereditary are environmental. Nevertheless, they are also inborn and cannot easily be eradicated by education. Therefore the chance that ordinary normal people carry a dangerous heredity is reduced, but the responsibility of parents to see that their children are properly born is increased. In the second place, it becomes more evident than ever that fitness for marriage implies intelligent willingness and persistence in acting upon the discoveries of science in whatever way may be best for the unborn child. We have long insisted upon the right environment for the expectant mother during pregnancy. The new discoveries suggest that we must insist equally upon the right environment and manner of life before pregnancy begins.
This brings up a very interesting question upon which biologists are not agreed. Does what has just been said about the period before pregnancy apply to the father as well as the mother? Many biologists doubt whether we have any proof that environmental influence can weaken the sperm cells of the male in such a way that the offspring are thereby weakened. Other biologists, such as Professor Pearl, of Johns Hopkins University, and Professor C. A. Mills, of Cincinnati, have made some interesting experiments which lead them to believe that sperm cells weakened by environmental conditions may affect the vitality of the developing offspring. In short, at the present time there is no agreement among competent scientific men that the health and mode of life of the father, as well as of the mother, influence the physical well-being of the developing child, and thereby affect its emotional stability and other qualities. Until this question is scientifically settled it is obvious that the men best fitted for marriage and parenthood are those who act in such a way that they cannot harm their children no matter which view is correct.
Let us return once more to the problem of deciding how far the mental and social characteristics of ourselves and of the persons we are interested in are due to inheritance and how far to pre-natal and postnatal environment. In the present state of knowledge no exact decision is possible. Nevertheless, in some families an undesirable trait is exhibited by a parent, brothers or sisters, and perhaps by more distant relatives. In such cases, it is probably inherited, or at least due to an inherited deficiency or tendency of some sort, and there is a chance that it may be handed down to the next generation. On the other hand, many persons who suffer from some form of emotional instability come from families in which the parents and near relatives appear normal in this respect. In such cases it is probable that the trait is not hereditary, but due to some influence in pre-natal life or childhood. Until the sciences of human genetics and eugenics have made more progress, the safest way to judge in such matters is by the qualities of a family as a whole.
Whether you have any doubt about this or not, a thorough examination by a good physician who is also a psychiatrist and a man of fine character will be a great help. The physician must frame his judgments for the good not only of the individual who consults him, but of the prospective partner, and of the children who may be born to such a couple. Even the best physician is often unable to decide whether a given defect is hereditary. He can merely frame an opinion based on the whole family. Young people find it hard to believe that they marry into families, but they do. As the old Jewish saying puts it, "It is not good to marry a maid who is the only good maid in her family." The responsibility that thus rests on physicians is tremendous. That of the young people who wish to be married is also great, but very different. Theirs is to submit themselves fully and frankly to the physician's examination and advice. He may decide that it is safe to marry a person of stable temperament, but not one who is nervously unstable.
It must always be remembered that even if the physician has given you a clean bill of health, you are still unfit for marriage unless you are willing to go more than halfway in adjusting your life to "his" or "hers." Lovers generally feel sure that they can do this, but have you proved it in your treatment of parents, brothers, sisters, and friends? If you are free from transmissible disease and innate defects, and if you are capable of having children, it is still unwise for you to marry unless you display good evidence of the qualities which make a happy home and insure the right training of children. Darwin once said that the trouble with mankind is not lack of ability, but failure to use the abilities that we possess. Even if it is not wise for you to marry now, perhaps you can take yourself by the scruff of the neck and make yourself fit.
If you are fit, the next question is, "Is it wise for me to marry?" For the vast majority of people the answer is emphatically "Yes" both for your own sake and that of society as a whole. For most people the married state is happier and more useful than the unmarried state. Biologically the two sexes are meant to live together. Long experience has proved that the only permanently happy way of living together is as husband and wife. If the marriage is of the right kind, both the man and the woman become happier, healthier, more adaptable, more interested in the community, and, in many cases, better workers. Marriage is unquestionably one of the best schools and one of the best health resorts. It often has a wonderful effect in steadying people's nerves, provided the partner is wise as well as loving.
The probability that any given marriage is wise is greatly increased where the two young people have reasonably similar ideals and habits and are sufficiently intelligent so that each can enjoy the interests of the other. It is increased still more when both the man and the woman realize that marriage is a comparatively hollow affair unless entered into with the purpose of having a family. Few experiences have greater value than the sacrifices which parents must make if they are to create a real home. The making of such a home brings out the best that is in people. Hence from the purely personal standpoint marriage is a priceless advantage.
There is a social as well as a personal side to marriage. The unstable conditions of the present century have made some people believe that the family is a thing of the past, but this is a mistake. The family life of the future will be different from that of the past, but the finest traits in it will still be the same. Loyalty of each to all and all to each is one of the greatest assets in this tumultuous, changing world. In times of distress, whether it is financial or mental, the most pitiable person is the one without family ties. A family of children may be a handicap at such times, but often it is the very thing that keeps people from failure. Moreover, in adversity and old age a family group of loyal brothers and sisters, even if each has several children, gets along much better than does the man or woman who fends only for himself. It pays to be married and to be married into a large family.