Relationship quality affects siblings' mental health, risky behaviors

"Similar to work with European-American and African-American families, we found adolescents with sibling relationships characterized as positive or negative, and we also found a group that we labeled 'affect-intense' because siblings in this group experienced moderate levels of intimacy and negativity," said Sarah Killoren, an assistant professor of human development and family science at MU. "An important difference, however, is that we didn't find an 'uninvolved' group among Mexican-origin siblings in which siblings have low levels of intimacy and low levels of conflict. This may be due to the cultural emphasis Latino families place on family interdependence. Research shows Mexican-origin siblings spend more time with their brothers and sisters than with their parents and their peers during adolescence."

Killoren and her colleagues used in-home interview data from a multi-year study of 246 Mexican-origin families living in the United States. The researchers studied pairs of siblings in which the siblings ages were around 12 and 15 at the beginning of the study when researchers assessed the siblings' relationship qualities. The researchers examined how siblings' relationship qualities in adolescence were related to each sibling's depressive symptoms, risky behaviors and sexual risk behaviors five and eight years later.

Older siblings who had positive relationships with their younger siblings had the fewest depressive symptoms and engaged in the lowest levels of risky behaviors. Overall, siblings with positive relationships engaged in less risky behaviors, whereas siblings with negative relationships engaged in more risky behaviors. Younger siblings who had a negative relationship with an older, opposite-sex sibling had increased sexual risk behaviors.

"Individuals learn how to interact with others based on the relationships they have with their siblings," Killoren said. "Siblings who are hostile and negative with one another will use that interaction style with their peers. Most peers won't respond well to hostility and negativity so these youth may be more likely to hang out with a deviant peer group and, in turn, engage in risky behaviors."

Killoren said parents also play an important role in socializing their children to value family. Parents should encourage their children to spend time with their brothers and sisters, to be positive role models for their siblings and to take care of each other. By instilling those values, parents can encourage positive sibling relationships that children will want to maintain throughout adulthood, Killoren said.

"The longest-lasting relationships individuals can have are with their siblings," Killoren said. "It's important to develop and maintain close relationships in adolescence because they are important throughout the lifespan, especially after siblings lose parents and spouses."

All of the sibling pairs Killoren studied had two biological parents and other siblings living in the home. Killoren said family relationships are complex, and this research is a first step in understanding intricate family dynamics among Mexican-origin families. Future research should examine sibling relationships in other family types, such as stepfamilies or single-parent homes, she said.

The article, "Profiles of Sibling Relationship Quality: Links to Familism Values and Adjustment," will be published in the International Journal of Behavioral Development.