Education, income and offspring count in men and women. Evolutionary explanations hold true in modern societies.

Martin Fieder, University of Vienna
Susanne Huber, Research Institute of Wildlife Ecology, University of Veterinary Medicine

Demographic data typically rely on the number of offspring women have. This may blur the results when analysing the relationship between the number of offspring and socio-economic status in modern societies. On the basis of data from contemporary Sweden, we propose that sampling the number of offspring for men and women as well as analysing the association between numbers of offspring, income and education separately for men and women will lead to different results from many demographic studies. We show that for women, education and income are negatively associated with number of offspring, whereas for men, we find a positive association between number of offspring and income and education. We conclude that it is crucial to survey offspring number for both men and women in order to understand fertility patterns in modern societies. We further conclude that evolutionary assumptions about human reproduction may be fundamental for the understanding of demographic developments in modern societies.