The Importance of Sibling Involvement on Adolescent Academic Success

Background:  Sibling relationships play a crucial role in one’s development, with research finding siblings to contribute to a variety of social and cognitive outcomes. Birth order, as well as the presence of siblings, have also been related to IQ and lifelong success. However, few studies have investigated the potential influence of sibling support and closeness on academic success.  While some research suggests academic support from older siblings reduces academic achievement among younger children, it remains unclear if quality of sibling relationships can affect academic achievement during adolescence. This study aims to examine whether psychosocial and academic support from siblings is associated with increased academic achievement. It is hypothesized that increased sibling support will be positively associated with academic success.  

Methods:  The study uses the Early Childhood Longitudinal Study-Kindergarten Cohort (ECLS-K), a nationally representative and longitudinal data set including about 21,260 kindergarteners in the 1998-1999 school year, to examine the association between sibling relationship and academic achievement. Academic achievement was indicated by reading and math test scores. Sibling relationship was constructed based on children’s responses to whether they talk to a brother or sister when they need help with homework, to be cheered up, or advice about making important decisions. All variables were measured in the 2006-2007 school year. A series of linear regression models were applied to predict academic achievement from sibling relationship, and the analyses were adjusted by the weight variable provided by the ECLS-K.

Results: Math scores were positively predicted by sibling assistance on homework, but negatively predicted by seeking advice from siblings or self-report of siblings as a source of cheering-up.  Similarly, reading scores were positively predicted by sibling assistance on schoolwork, with sibling homework assistance positively predicting increased scores and reporting a sibling as a source of cheer negatively predicting reading scores; however, reading scores were not significantly different based on whether advice was sought from siblings.  Additionally, both reading and math scores were negatively predicted by parent report of sibling assistance on schoolwork.  Demographically, gender, race, and socioeconomic status were all found to positively predict seeking sibling assistance with homework.  Self-reporting as female or belonging to a minority all predicted increased likelihood of reporting sibling assistance, with socioeconomic status (SES) predicting a 2.8% higher likelihood of using sibling assistance.  

Conclusions: Our results contradict prior research on the role of sibling support in academic achievement. Although research suggests that sibling relationships become strained in adolescence, with more children reporting increased reliance on peers, the results suggest that sibling psychosocial and academic support remain important to adolescent academic success.  Lower SES negatively predicted sibling assistance on schoolwork with those reporting higher household income reporting increased use of sibling assistance.  These results suggest that young adolescents with lower SES may seek more external assistance with schoolwork.  By increasing our knowledge of family and sibling relationships, additional pathways may be identified to increase student’s academic performance.