Intergenerational support and women’s fertility in high-income countries: an evolutionary analysis

Abstract

There is now considerable evidence that humans are cooperative breeders – that is, women need allomaternal support to successfully reproduce. Families play a key role in providing this support to women. Evidence from low-income contexts linking allomaternal support to beneficial child outcomes is particularly strong, but associations between support and successful reproduction are more varied in high-income settings and when fertility is the outcome. Two possible reasons for this are (1) allocare is measured in many forms and at many time points with potentially different meanings for reproductive women, and (2) highincome populations are very heterogeneous, including large socioeconomic inequalities, which may modify associations between support and fertility. This publication-based dissertation has three main objectives: (1) to contribute to cooperative breeding literature in high-income, low-fertility settings; (2) to deepen our understanding of how family support plays into reproductive decision making by testing associations between many types of support and women’s fertility; and (3) to explore contextual factors, particularly socioeconomic position, with may moderate associations between family support and women’s fertility. These objectives are investigated in four research chapters (two published and two written for submission) using secondary data from low-fertility, high-income countries. This research firstly confirms that families provide key allomaternal support for women in high-income countries, while also highlighting other sources of support. However, the results demonstrate that all support is not equal. Types, timing, and sources of support vary in terms of their influence on reproductive outcomes (e.g.in the United Kingdom, material or practical support often associates with lower fertility while non-material support associates with higher fertility). Secondly, this research demonstrates that socioeconomic environments modify many components of the reproductive decision making process, not the least of which is how families interact with and support each other and, in turn, how family support associates with fertility outcomes.