A dyadic analysis of sibling perpetrated abuse in childhood on negative affect in adulthood among dizygotic twins: Contemporary family strain as a Moderator

Sibling abuse is one of the most common forms of maltreatment, yet it has been overlooked by researchers and clinicians alike. Sibling relationships are generally the most enduring relationships individuals have, even when there is sibling-perpetrated abuse in childhood. Supportive and strained relationships with family members may protect against or amplify negative affect resulting from sibling-perpetrated abuse in childhood, yet these propositions have yet to be tested. To address the aforementioned gap, we utilized two waves of data nine years apart from the study of Midlife Development in the United States, using retrospective measures of sibling-perpetrated abuse. A sample of dizygotic twins (n = 221) was analyzed to address gender, age, and birth order effects, and utilized a longitudinal actor-partner independence moderation model. Results indicate a significant interaction between the male twin’s reports of higher levels of female twin perpetrated abuse in childhood and the male twin’s reports of higher levels of current family strain in adulthood (+2 SD above the mean), where the interaction term predicted higher levels of negative affect in the female twin. Models with family support included did not converge, so findings could not be evaluated. Sensitivity analyses indicate there was no mediating effect. We found evidence that a male’s experience of historical abuse and family strain in adulthood crosses over and influences the female twin’s mental health which may be a function of gender socialization and the female twin being more central to maintaining familial relationships over time.