The relationship between perceptions of mortality and fertility preferences from an evolutionary standpoint: evidence from a large scale internet based psychological experiment involving students at the London School of Economics

Paul Mathews, London School of Economics and Political Science (LSE)
Rebecca Sear, London School of Economics and Political Science (LSE)

Both demographic transition and life history theory predict that fertility responds to changes in mortality, but there have been relatively few tests which identify links between mortality perceptions and fertility preferences at the individual level. This paper provides an individual-level investigation of the relationship between mortality and fertility, by testing whether mortality priming results in an increase in fertility preferences. Data were collected via an internet-based experiment of students at the London School of Economics (LSE), who were randomly allocated between two questionnaires. The treatment questionnaire asked a set of mortality priming questions and then collected information on fertility preferences and attitudes towards the costs and benefits of children. The control questionnaire recorded information on fertility preferences without prior mortality priming. The results suggest that mortality priming resulted in higher ideal number of children for males, but not for females. There were no significant differences in the attitudes towards the costs and benefits of children for either sex, though the raw data suggest a slight shift towards viewing children as less costly after mortality-priming, particularly for men. This paper therefore argues that the reaction of fertility to mortality may be at least partly mediated by a direct psychological link between mortality perceptions and reproductive behaviour.