Ralf Kaptijn

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Socio-economic status is an important determinant of health and survival in rural Africa and necessitates a practical and valid instrument to implement in health studies. Our objective was to investigate the validity of the rapid appraisal method to assess socio-economic status and its ability to identify individuals at risk. Among 1573 households in rural(More)
This study tests two evolutionary hypotheses on grandparental investments differentiated by the child's sex: the paternity uncertainty hypothesis and the Trivers-Willard hypothesis. Data are from two culturally different countries: the Dutch Longitudinal Aging Study Amsterdam (n=2375) and the Chinese Anhui Survey (n=4026). In the Netherlands, grandparental(More)
Several hypotheses have been put forward to explain the relationship between women's fertility and their post-reproductive longevity. In this study, we focus on the disposable soma theory, which posits that a negative relationship between women's fertility and longevity can be understood as an evolutionary trade-off between reproduction and survival. We(More)
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