Fertility and social mobility

This article contains an analysis of part of the results of an inquiry into social mobility undertaken jointly by the Nuffield Research Unit of the London School of Economics and the Population Investigation Committee, in collaboration with the Ministry of Labour, based on nation-wide sample material collected by the Social Survey in England and Wales in 1949. Grateful acknowledgment is made to the Inter-Departmental Committee on Economic and Social Research for facilitating the collaboration with these government departments. In this paper, the relationship between fertility defined in terms of average family size of marriages of at least twenty years duration and social mobility is discussed. Two aspects of the latter phenomenon are discussed, namely, the position of sons on the social scale in relation to that of their fathers, and the change in the social status of a family in the period between the date of marriage and the date of the inquiry.

The conclusions reached stand in apparent contradiction to R. A. Fisher's ‘Theory of Infertility Selection’. It is shown that socially promoted families tend on the one hand to carry with them the family-building habits of the class of their origin, and, on the other, to acquire to some extent the fertility characteristics of the class into which they move.

The study of ‘personal’ social mobility throws some light on the question of the choice of the time-basis of socio-economic status allocation.