Differential grandparental investment - the impact of phenotypic resemblance.

Abstract

Differential grandparental investment is mainly explained as a result of paternity uncertainty. Phenotypic resemblance may be interpreted as an indicator of genetically relatedness. Consequently the present study focused on the impact of phenotypic resemblance on grandparental investment, i.e. solicitude, contact frequency and quality of relationship. 213 adults persons between the age 19 and 32 years (x = 25.5; SD = 3.4) were enrolled in the study. Data concerning grandparental investment during childhood were collected retrospectively using a 30 item questionnaire. Grandparental investment patterns differed significantly according grandparent category. In detail maternal grandmothers showed the highest contact frequency and the highest solicitude while - as to be expected - the paternal grandfather exhibited the lowest degree of investment. Grandparental investment was independent of grandparent category mainly influenced by residential distance. Phenotypic resemblance had an impact on grandparental investment independent of residential distance. This was first of all true of paternal grandfathers. An impact of phenotypic resemblance on grandparental investment patters can be assumed.