HISTORY OF 100 BABIES
Fig. 42.—The top of the diagram shows the children "starting from scratch." By following down the vertical lines, one can see that their longevity depends largely on the size of family from which they come. Those who had 10 or a dozen brothers and sisters are most likely to live to extreme age. Alexander Graham Bell's data, 2964 members of the Hyde family in America.
ADULT MORTALITY
Fig. 43—If child mortality is eliminated, and only those individuals studied who live to the age of 20 or longer, the small families are still found to be handicapped. In general it may be said that the larger the family, the longer a member of it will live. Large families (in a normal, healthy section of the population) indicate vitality on the part of the parents. This does not, of course, hold good in the slums, where mental and financial inefficiency are abundant. Within certain classes, however, it may be said with confidence that the weaklings in the population are most likely to be from small families. Alexander Graham Bell's data.
1. The supposed inferiority of first-born children has been debated at some length during the last decade, but is not yet wholly settled. It appears possible that the first-born may be, on the average, inferior both physically and mentally to the children who come directly after him; on the other hand, the number of first-born who attain eminence is greater than would be expected on the basis of pure chance. More data are needed to clear up this problem.[168]
2. The advantage to a child of being a member of a large or small family is a question of importance. In these days of birth control, the argument is frequently heard that large families are an evil of themselves, the children in them being handicapped by the excessive child-bearing of the mother. The statistics cited in support of this claim are drawn from the slums, where the families are marked by poverty and by physical and mental inferiority. It can easily be shown, by a study of more favored families, that the best children come from the large fraternities. In fact Alexander Graham Bell found evidence,[169] in his investigation of the Hyde Family in America, that the families of 10 or more children were those which showed the greatest longevity (see Figs. 42 and 43). In this connection, longevity is of course a mark of vitality and physical fitness.
3. The question of the effect of child-bearing on the mother is equally important, since exponents of birth control are urging that mothers should not bear more children than they desire. A. O. Powys' careful study[170] of the admirable vital statistics of New South Wales showed that the mothers who lived longest were those who bore from five to seven children.