Having a sibling has many positive impacts, study says

iStock/Yuri Arcurs

For anyone who has refereed a sibling shouting match, it might be easy to question how beneficial it is to have a brother or sister. But recent research underscores the positive impact that these relationships can have.

In a study published in the Journal of Research on Adolescence last fall, Brigham Young University researchers found that sibling relationships help kids develop sympathy, which over time can foster “prosocial” behaviors such as helping and sharing with others. This effect was independent of children’s relationships with their parents and friends.

Whether or not siblings fight wasn’t the biggest factor; what mattered most was that they have affection for each other, says study coauthor Laura Padilla-Walker. The findings showed that boys and girls benefit equally from positive sibling relationships — a surprise to the researchers, since boys typically report less of a benefit from peer relationships than do girls.

“Siblings provide a unique opportunity for children and teens to resolve conflict and take the perspective of another person, both of which promote feelings of caring and concern,” Padilla-Walker said in an e-mail. Disputes between young sibs give parents a chance to help kids see each other’s viewpoint and understand how their behavior makes others feel, she added.

Encouraging good sibling relationships is particularly important given that hostile brother or sister relationships (i.e., those lacking in affection) were correlated with subsequent depression in boys and girls and behavioral problems in boys. By helping children resolve conflict without aggressive or unkind words and behaviors, parents can help children learn these skills on their own, Padilla-Walker says.

Sympathy and helpfulness aren’t the only potential benefits of sibling relationships. Research out of the University of Essex in England found that they can also help boost younger siblings’ grades.

Looking at national exam marks over four years, researchers Cheti Nicoletti and Birgitta Rabe found that for each test grade improvement by an older sibling — for example, from a B to an A — the younger sibling’s marks rose by 4 percent. The effect was greater among siblings from poorer families, for which each test grade improvement by the older sibling was linked to an 11 percent increase in the younger one’s scores.

The study was meant to determine whether investments in education might have “multiplier” effects through impacts on younger children. The researchers found the improvement to younger siblings’ scores was equal to the impact of spending around 670 pounds extra per year (a little over $1,000) on the younger sibling’s schooling.

Teaching younger siblings, helping with homework, and passing on information about schools and teachers are among the ways that older siblings can directly affect younger brothers or sisters’ grades, the researchers wrote.