The “Kinship Penalty”: Parenthood and In-Law Conflict in Contemporary Finland

Intergenerational relations between affinal kin create both support and tensions to family members. Previous studies indicate that relations with affines may change once a grandchild is involved, yet this has not been explored with respect to conflicts. We use survey data of contemporary Finns (n = 1202) to investigate how parenthood is associated with the likelihood of reporting conflicts with one’s own parents and parents-in-law. Based on inclusive fitness theory, we hypothesise that affinal kin will be treated more like biological kin if a couple has children as compared to childless couples. Results show that overall, Finns reported higher conflict occurrence with their own parents than with their in-laws. Compared to childless couples, parents were as likely to report conflicts with their own parents, but more likely to report conflicts with their parents-in-law. Results were robust after taking into account several sociodemographic factors as well as the contact frequencies and emotional closeness between the parties concerned. Daughters-in-law were more likely to report conflicts when paternal grandmothers provided more grandchild care, indicating that the conflict measure used here is indeed related to investment in offspring. We conclude that shared relatedness to a grandchild renders affines “more like kin” with regards to conflicts, indicating the existence of a “kinship penalty” in family relation in addition to the previously reported “kinship premium”.