Evolutionary Human Sciences (Jan 2024)

The role of mating effort and co-residence history in step-grandparental investment

  • Jenni E. Pettay,
  • David A. Coall,
  • Mirkka Danielsbacka,
  • Antti O. Tanskanen

DOI
https://doi.org/10.1017/ehs.2024.17
Journal volume & issue
Vol. 6

Abstract

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The prevalence of divorce in both parental and grandparental generations has led to a rise in the number of children who now have families that include both biological and step-grandparents. Despite the thorough examination of biological grandparents’ contributions in the recent literature, there remains a scarcity of studies focusing on the investment of step-grandparents. Using population-based data from a sample of 2494 parents in Germany, we assessed grandparental investment through financial support and assistance with childcare of grandparents (N = 4238) and step-grandparents (N = 486). The study revealed that step-grandparents provided lower levels of investment in their grandchildren compared with biological grandparents. Furthermore, the study identified that a longer duration of co-residence between step-grandparents and parents earlier in life did not correspond to an increase or decrease in step-grandparental investment. However, investment by separated biological grandparents increased with the increasing length of co-residence with parents. In line with the scarce literature on step-grandparental investment, these findings indicate that mating effort may be the most important motivation for step-grandparental investment.

Keywords