do exist, are quite negligible in their influence on conduct, on account of the repressive effect of environment or on account of the lack of any positively encouraging aspects of environment. If we could be at all certain that the natural inclination to reproduction was adequately measured in different people by the size of their families, it might greatly modify our attitude toward the differential birth rate in different classes of our population. But we are forced to conclude, in studying the actual situation, that there is no natural working out of hereditary inclinations apparent in our present birth rate. Social conditions rather than hereditary inclinations determine the greater part of the differentials we have been studying thus far.
To sum up our findings with regard to these smaller cities, we may say that they are much like the larger cities in the operation of the measurable factors influencing the ratio of children to women. At no point do any directly opposed tendencies appear in the two groups. The distinctive features of modern urbanism which first become manifest in the larger cities soon penetrate into these smaller places, at least as regards those attitudes of mind affecting the raising of children.
We have seen that some cities differ greatly from the others, but we have generally found a more or less satisfactory explanation of these differences in the particular circumstances existing in different localities which have impeded or abetted the spread of conditions favorable or unfavorable to the raising of children. In other words, the differences between cities appear to be based largely upon the degree of pressure felt by those raising children and the extent of their knowledge of methods of conception control. Some people feel the burden of children much more keenly than others; although this feeling of the burdensomeness of children, no doubt, is itself largely a measure of the extent to which the inclination to self-development in the individual has been encouraged at the expense of the inclination to reproduction. It seems evident that our present urban life tends to smother the inclination to reproduction under the avalanche of the individual's desires for pleasure and self-development. The modern city apparently furnishes abundant incitement to people to develop their personal qualities, particularly those that are immediately useful in attaining a desired status, and to work hard to satisfy all kinds of personal desires, but it furnishes little incentive to taking long time views or to the development of inclinations not of immediate use.