The relationship between adolescent sibling bullying and emerging adult loneliness and psychological wellbeing

Social and emotional development are pivotal to later psychological health and can be understood through attachment theory and social learning theory. Sibling relationships are relatively under-researched yet important influences in child development, and one area related to psychological and social wellbeing is sibling bullying. Emerging adulthood is also an increasingly recognised unique life stage where psychosocial difficulties are common. The longitudinal evidence base has mostly focused on adolescent research and has not studied loneliness. There is also emerging evidence of dose-response associations. This study aimed to fill gaps in the literature by exploring the relationship between adolescent sibling victimisation and perpetration and emerging adult loneliness, psychological distress, and mental wellbeing. This study also aimed to explore the possible dose-response relationships of sibling victimisation and perpetration with these outcomes. This study involved secondary data analysis of data from Understanding Society, utilising a longitudinal observational design following participants from early adolescence into emerging adulthood. Regression analyses were run, and the results indicated that adolescent sibling perpetration was positively related to emerging adult loneliness and psychological distress for females. This study also found dose-response relationships for males, with more sibling victimisation and less sibling perpetration associated with higher loneliness scores, and sibling victimisation positively associated with psychological distress. No such relationships were found for mental wellbeing, although this may be due to sample limitations. The findings are discussed in relation to theory and recommendations for future research are considered in the context of the exploratory nature of this study and its strengths and limitations. Possible implications of the findings, including raising awareness of risk factors, and informing sibling bullying prevention and therapeutic intervention for those most at risk, are also discussed.