Cooperation and Conflict. Sibling Relations in Contemporary Societies.

This study investigates sibling and “extended sibling” relations. Extended sibling relations refer to relations between nieces or nephews and aunts or uncles. Both cooperation and conflict between kin are investigated. We use an evolutionary family sociological framework for analysing kin relations in present day Finland and the UK. Cooperation is measured by kin support, emotional closeness, and contact frequency, while the outcome of sibling conflict is measured by toddlers’ unintended injuries, young adolescents’ reports of how much siblings picked and hurt each other, and adults’ self-reported disagreements with siblings. The study includes seven original articles and an introductory chapter.

Article I shows that 3-year-old British children who live in the same household with their full siblings have a lower risk of unintended home injuries than do children who live with their full and half siblings or only with their half siblings. Article II finds that 11-year-old British children living with their full siblings only were more likely to report hurting or picking between siblings compared with children who live with their half siblings only. Article III describes two generations of adult Finns and shows that both younger (mean age 36 years old) and older (mean age 65 years) generations have more contacts with full than half siblings and more contacts with the children of full siblings than with children of half siblings. Based on article IV, older and younger Finns have more contact with their sisters’ children compared to their brothers’ children. Article V finds that childless younger women in Finland provide more childcare to their siblings’ children than do younger mothers. However, mothers and childless women provide equal amounts of support to their aunts and uncles. According to article VI, younger Finnish adults who have half siblings are more likely to have encountered unequal maternal treatment than younger adults who have full siblings only. Article VII shows that younger and older Finns are more likely to have conflicts with their full siblings than with their half siblings.

Combined, these results show that kin relations tend to differ both between maternal and paternal kin and between full and half siblings. Moreover, kin support is more likely to flow from older individuals to younger ones than vice versa. Finally, parental unequal treatment seems to shape relations between siblings. At the end of the introduction chapter, policy and practical implications of the results are discussed.