Sibling Conflicts in Full- And Half-Sibling Households in the Uk

Abstract

Sibling relations are by nature ambivalent with high levels of both altruistic helping and competition. Higher relatedness is often assumed to reduce the occurrence of conflicts between siblings, but evidence of this has been scarce and mixed. Siblings typically compete over resources and parental attention, and parental constellations vary with sibship types. Since full-siblings compete over the same two biological parents, while half-siblings have only one shared biological parent and often a higher number of parents overall, it is hypothesized that conflicts are more common between full- than half-siblings. This study tested this assumption using the British Millennium Cohort Study (n=7527 children at age 11). Conflicts were measured as children's reports of how much siblings picked on and hurt each other. Households with full-siblings only, maternal half-siblings only, and both full- and maternal half-siblings were compared. The results show that children who were living with only their full-siblings were more likely to experience sibling conflicts compared with children living with their maternal half-siblings only. This was the case also after controlling for several potentially confounding variables. The results suggest that differential access to parental resources of available biological and step-parents may explain the higher amount of sibling conflict between full- compared with maternal half-siblings.

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

“…Overall, both men and women were more likely to report conflicts with their own parents than with their parents-in-law. This finding is similar to recent studies of the effect of genetic relatedness on conflict proneness between siblings (Salmon and Hehman, 2015;Tanskanen et al, 2016aTanskanen et al, , 2016b,…”

“…One reason for conflicts within close family is that family members compete over resources, and the severity of kin competition may reduce or even overrun the tendencies to altruistic helping among kin (Griffin and West, 2002;Mace, 2013;Tanskanen et al, 2016aTanskanen et al, , 2016b. Inclusive fitness theory has usually been interpreted as predicting less competition and fewer conflicts with close genetic kin compared to more distant kin and non-kin (e.g., Salmon and Hehman, 2014).…”

Sibling Bullying in Middle Childhood is Associated with Psychosocial Difficulties in Early Adolescence: The Case of Individuals with Autism Spectrum Disorder

“…Structural family-level factors may also be important from an evolutionary perspective where siblings are considered as natural born competitors for limited parental resources including affection, attention or material goods (Dantchev and Wolke 2019;Tanskanen et al 2017). Children and adolescents with ASD might get priority access to these limited parental resources.…”

Diluted Competition? Conflicts between Full- and Half-Siblings in Two Adult Generations

“…Nevertheless, recent evidence, intriguingly, indicates that this may not be always the case. Two recent studies among US college students (Salmon and Hehman, 2015) and British adolescents (Tanskanen et al, 2016) found full siblings to experience more conflicts than half-siblings. Sibling conflict occurrence has not, however, previously been studied among adults using large and representative data, which is the purpose of our study here.…”

“…By contrast, however, for the non-overlapping part of their kin networks, half-siblings can be predicted to exhibit no or very little competition toward each other. We call this the diluted sibling competition hypothesis (Tanskanen et al, 2016; see also Michalski and Euler, 2008).…”