THE NATURAL HISTORY OF POPULATION

By Raymond Pearl '99, Oxford U. Press, 1939, 416 pp. $3.50.

In this work, Professor Pearl adds another to his impressive series of contributions in the field of the sociobiological aspects of human fertility. Starting with general biological principles, he proceeds to the discussion of the interrelationship of that complex group of variables, including social, economic and biological factors, which appear to have some bearing, direct or indirect, on human fertility. Sexual desire, the span of reproductive life, reproductive wastage, nativity, race (colour), age patterns, these are some of the factors analyzed and correlated. At some points conclusions emerge which are strikingly divergent from the researches of others, as represented in excellent bibliographical references.

Perhaps the most unique contribution of this work lies in an analysis of the extent of contraceptive effort in the American population as determined by reports made by the obstetrical divisions of urban hospitals in fifteen states. Detailed and reliable information on 30,949 cases coming from 139 hospitals was obtained. Making due allowance for possible errors arising from such factors as the nature of the data, its representativeness as to age, color and general population composition, and the probability of continued success in the practice of contraception as eliminating a sizeable group from obstetrical care, the author concludes that the proportion of white contraceptors in the general population does not exceed 55 to 60 per cent.

What gives rise to our present high differential fertility rates among social classes? On the basis of a number of comparative studies, Pearl is convinced that the answer to this question is to be found solely in the effects of contraceptive efforts together with the practice of criminal abortion and the postponement of marriage. To the general reader this may seem the obvious conclusion but not to the student of population problems.

If the protagonists of contraception are heartened by the author's conclusion just stated, he quickly dispels their pride of achievement. In examining world population trends, he finds that after a gooyear period of acceleration of scientific knowledge and population growth, this phenomenal situation has been followed by generally declining birth rates all over the world. Such declines are not to be attributed to state planning nor wholly to individual planning. "Rather, what is going on appears to be a much more complex biological adjustment or adaptation involving many factors Among these factors an important one is conscious individual contraception, but probably nowhere the only important one." (p. 286.)