DIFFERENTIAL FERTILITY IN MADISON COUNTY, NEW YORK, 1865

Abstract

HE hypothesis that the "normal" pattern of differential fertility in a population is that of a "J" shaped curve rather than a straight line inverse relationship between birth rates and social status has gained increasing acceptance in recent years. According to the interpretation of the history of these patterns, the straight line inverse relationship is a product of the diffusion of contraceptive information through a population, beginning in the upper classes and in the urban centers and spreading downward and outward. Most of our reliable information about differential fertility falls into the period of this transition, and actually toward the end of it as we can make out the cycle.2 Verification of the "J" hypothesis depends upon the most recent census information in the United States and Europe,8 and this is necessarily incomplete. The surge in the birth rate of these nations during the 1940's and early 1950's is closely related to the rapidly rising marriage rate and consequent speeding up of family formation. Not until reproductive histories of this generation of wives is more complete can we be certain, even though there are many indications in census materials,4 of some real change in family size. Another source of materials for the verification of the "J" hypothesis can be in the historical period before the beginning of this transitional period. Unfortunately, Western nations in this stage of the cycle rarely collected census information usable for this analysis, and this has also been true of those non-West-