1 Evolution and Behaviour Research Group, Division of Psychology, Newcastle University Henry Wellcome building for Neuroecology (Newcastle University), Framlington Place, NE2 4HH, Newcastle upon Tyne, United Kingdom
| 2 Evolution and Behaviour Research Group, Newcastle University Henry Wellcome Building, Framlington Place, Newcastle NE2 4HH, UK.
suggests that maternal grandparents will invest more in their grandchildren
than paternal grandparents, due to the difference between the certainty of
maternity and the uncertainty of paternity. Tests of this prediction have
tended to use retrospective ratings by grandchildren rather than self-reported
behaviour by grandparents. Using a large-scale dataset from the Netherlands, we
show significant differences between maternal and paternal grandparents in
terms of frequencies of contact with their grandchildren, while controlling for
a wide range of other variables. Our results show biases consistent with the
paternity uncertainty hypothesis.