Caroline Uggla

Family Structure and Health in the Developing World: What Can Evolutionary Anthropology Contribute to Population Health Science?

In this chapter, we consider what evolutionary anthropology contributes to the study of population health, focusing specifically on family structure and its relationship to child and adult physical health. Evolutionary anthropologists have now built a substantial body of literature on relationships between family structure and various dimensions of human wellbeing, particularly in the context of small-scale ‘traditional’ societies and developing rural communities most at risk of poor health outcomes. Crucially, they have also constructed theoretical models to account for variation in key dimensions of family structure in relation to individual, ecological, and cultural factors. Thus, evolutionary anthropologists have much to say, not only about the extent to which specific family structures may influence health but also why certain family forms may persist or change across time and space. Here, focusing on studies primarily conducted in sub-Saharan Africa, we review the literature on three interrelated dimensions of family structure and their relationship to health: (1) family size, (2) polygynous versus monogamous marriage, and (3) the role of extended kin. Using these examples, we highlight the theoretical and empirical contributions of evolutionary anthropology and draw out implications for population policy and related initiatives seeking to improve family health in the developing world.

Effects of local extrinsic mortality rate, crime and sex ratio on preventable death in Northern Ireland

Variation in preventable death can be understood from an evolutionary life history perspective. However, previous studies have failed to isolate ecological effects on preventable death. We use population-wide Census data from Northern Ireland and find that extrinsic mortality rate and crime, but not sex ratio, impacts on male preventable death.

Adult sex ratio and social status predict mating and parenting strategies in Northern Ireland

Evidence from animal species indicates that a male-biased adult sex ratio (ASR) can lead to higher levels of male parental investment and that there is heterogeneity in behavioural responses to mate scarcity depending on mate value. In humans, however, there is little consistent evidence of the effect of the ASR on pair-bond stability and parental investment and even less of how it varies by an individuals mate value. In this paper we use detailed census data from Northern Ireland to test the association between the ASR and pair-bond stability and parental investment by social status (education and social class) as a proxy for mate value. We find evidence that female, but not male, cohabitation is associated with the ASR. In female-biased areas women with low education are less likely to be in a stable pair-bond than highly educated women, but in male-biased areas women with the lowest education are as likely to be in a stable pair-bond as their most highly educated peers. For both sexes risk of separation is greater at female-biased sex ratios. Lastly, our data show a weak relationship between parental investment and the ASR that depends on social class. We discuss these results in the light of recent reformulations of parental investment theory. This article is part of the themed issue ‘Adult sex ratios and reproductive decisions: a critical re-examination of sex differences in human and animal societies’.

Parental investment in child health in sub-Saharan Africa: a cross-national study of health-seeking behaviour

Parents face trade-offs between investing in child health and other fitness enhancing activities. In humans, parental investment theory has mostly been examined through the analysis of differential child outcomes, with less emphasis on the actions parents take to further a particular offspring’s condition. Here, we make use of household data on health-seeking for children in a high mortality context where such behaviours are crucial for offspring survival. Using Demographic and Health Survey (DHS) data from 17 sub-Saharan African countries, we examine whether maternal factors (age, health, marital status) and child factors (birth order, health, sex, age) independently influence parental investment in health-seeking behaviours: two preventative behaviours (malaria net use and immunization) and two curative ones (treating fever and diarrhoea). Results indicate that children with lower birth order, older mothers and mothers with better health status have higher odds of investment. The effects of a child’s sex and health status and whether the mother is polygynously married vary depending on the type of health-seeking behaviour (preventative versus curative). We discuss how these results square with predictions from parental investment theory pertaining to the state of mothers and children, and reflect on some potential mechanisms and directions for future research.

Unemployment, intragenerational social mobility and mortality in Finland: heterogeneity by age and economic context

Background We explore how mortality is related to unemployment and intragenerational social mobility in Finland. Unemployment and social mobility are two labour market experiences that are largely studied separately, despite the fact that selection processes into unemployment and downward mobility are intertwined. Because both causal and health selection mechanisms may vary depending on the timing of these experiences, we consider heterogeneity by age and economic context. Methods We run discrete time event history analysis for death (at age 30–75 years) in two periods (economic recession and growth) and analyse younger and older individuals and men and women separately. Results The odds of mortality were particularly high for individuals experiencing unemployment and when unemployment occurred during economic growth (OR ranging between 1.39 and 2.77). Younger men had high odds of mortality following unemployment (OR 1.86–2.77). In contrast, downward mobility was associated with higher odds of mortality only among older men and women and only during economic growth. The benefits of upward mobility were experienced mainly by younger men (OR ranging between 0.86 and 0.87) and were not experienced by women at all. Conclusion Results show that when in an individual’s life and the economic cycle unemployment and social mobility occur matters for whether these experiences are associated with mortality.

Higher divorce risk when mates are plentiful? Evidence from Denmark

Work from social and biological sciences has shown that adult sex ratios are associated with relationship behaviours. When partners are abundant, opportunities for mate switching may increase and relationship stability decrease. To date, most of the human literature has used regional areas at various levels of aggregation to define partner markets. But, in developed countries, many individuals of reproductive age spend a considerable amount of time outside their residential areas, and other measures may better capture the opportunities to meet a (new) partner. Here, we use Danish register data to test whether the sex ratio of the occupational sector is linked to divorce. Our data cover individuals in Denmark who married during 1981–2002 and we control for age at and duration of marriage, education and parity. Results support the prediction that a higher proportion of opposite-sex individuals in ones occupational sector is associated with higher divorce risk. This holds for both men and women, but associations are somewhat stronger for men and vary by education. Our results highlight the need to study demographic behaviours of men and women simultaneously, and to consider partner markets beyond geographical areas so that differing strategies for males and females may be examined.