Older siblings play an important role in the lives of their younger siblings. Like parents, older brothers and sisters act as role models and teachers, helping their younger siblings learn about the world. This positive influence is thought to extend to younger siblings' capacity to feel care and sympathy for those in need: Children whose older siblings are kind, warm, and supportive are more empathic than children whose siblings lack these characteristics. A new longitudinal study looked at whether younger siblings also contribute to their older sisters' and brothers' empathy in early childhood, when empathic tendencies begin to develop. The research found that beyond the influence of parents, both older and younger siblings positively influence each other's empathic concern over time.

The study was done by researchers at the University of Calgary, Universite Laval, Tel Aviv University, and the University of Toronto. It appears in the journal Child Development.

Researchers studied an ethnically diverse group of 452 Canadian sibling pairs and their mothers who were part of the Kids, Families, and Places project and from a range of socioeconomic backgrounds. They wanted to determine whether levels of empathy in 18- and 48-month-old siblings at the start of the study predicted changes in the other siblings' empathy 18 months later. The researchers videotaped interactions in the families' homes and mothers completed questionnaires. Children's empathy was measured by observing each sibling's behavioral and facial responses to an adult researcher who pretended to be distressed (e.g., after breaking a cherished object) and hurt (e.g., after hitting her knee and catching her finger in a briefcase).

"Although it's assumed that older siblings and parents are the primary socializing influences on younger siblings' development (but not vice versa), we found that both younger and older siblings positively contributed to each other's empathy over time," explains Marc Jambon, postdoctoral fellow at the University of Toronto, who was at the University of Calgary when he led the study. "These findings stayed the same, even after taking into consideration each child's earlier levels of empathy and factors that siblings in a family share - such as parenting practices or the family's socioeconomic status - that could explain similarities between them."

The researchers also examined whether siblings' development of empathy differed as a result of age and gender differences between siblings (e.g., younger brother/older sister versus younger brother/older brother). "The effects stayed the same for all children in the study with one exception: Younger brothers didn't contribute to significant changes in older sisters' empathy," Jambon notes. The influence of older brothers and sisters was also stronger in families in which the age difference between the siblings was greater, suggesting they were more effective teachers and role models, the study found.

"Our findings emphasize the importance of considering how all members of the family, not just parents and older siblings, contribute to children's development," suggests Sheri Madigan, Canada Research Chair in Determinants of Child Development and assistant professor of psychology at the University of Calgary, who coauthored the study. "The influence of younger siblings has been found during adolescence, but our study indicates that this process may begin much earlier than previously thought."

The authors suggest that an important next step is to determine if and how we can cultivate greater empathic tendencies in young children, and whether teaching one sibling, either older or younger, can in turn affect the empathy of the other sibling. Such work would also help address the broader question of how family interventions aimed at promoting positive developmental outcomes during childhood can benefit from focusing on relationships between siblings.

The Canadian Institutes of Health Research and the Social Sciences and Humanities Research Council funded the study.