Educational test scores among adolescents in three-generational households in 20 countries

Grandparental presence is often found to associate with improved grandchild wellbeing. However, studies have shown that the effect is not always positive. This could be explained by the fact that in some circumstances grandparents compete with grandchildren over parental time resources. We studied the assumption using data from the Program for International Student Assessment (PISA) from 20 Western countries (n=73,346 children at age 15). According to the results grandparental presence was associated with lower levels of parental involvement and decreased educational test scores among adolescents. Moreover, the results indicate that when the parental involvement is lower at the first place the grandparental presence tends to be associated with even weaker child outcomes. Finally, we found support that grandparental co-residence is a mediator of the association between parental involvement and child outcomes. These results are discussed with reference to the local resource competition model.