Marissa Nivison is postdoctoral research fellow, department of psychology, University of Calgary & Sheri Madigan is professor, Canada Research Chair in Determinants of Child Development, Owerko Centre at the Alberta Children’s Hospital Research Institute, University of Calgary.

In childhood, parents play important roles to set the stage for positive life-long relationships between siblings.

Sibling relationships are some of the longest-lasting linkages we have in our lives. Half of Canadians and around 80 percent of people worldwide have at least one sibling. Sibling relationships are unique from all other relationships because siblings often grow up together and share family history. Biological siblings even share genetics.

In childhood, children spend more time with their siblings than anyone else, including their parents. A longitudinal study found that the quality of sibling relationships in young adulthood was one of the strongest predictors of well-being at age 65.

Sibling relationships change as we grow. In early adulthood, maintaining the sibling relationship becomes a matter of choice, although most sibling relationships last a lifetime. In childhood, parents have important roles to play setting the stage for life-long positive sibling relationships.

As developmental and clinical psychologists, we recognize the profound impact siblings can have on development, especially having personally experienced the benefits, and sometimes the frustrations, within our own sibling relationships.

Sibling relationships & child development
Not only is the sibling relationship unique, but it also plays an important role in children’s development. Children with siblings tend to develop better relationships with their peers, engage in more creative play and have higher empathy and a better understanding of others’ thoughts and sentiments. They often develop social skills much earlier than children without siblings, which helps them form friendships when they start school.

Some studies have shown that positive sibling relationships also serve as a protective factor during difficult times, like high levels of life stress and marital conflict between parents.

It is not surprising that siblings can have a large impact on an individual’s development. For example, children often adjust their personalities to avoid conflict and competition with their sibling. Additionally, just knowing they have a sibling can positively affect a child.

Sibling conflicts, rivalry
When we are kids, sibling relationships can be full of rivalry. In adolescence, sibling relationships tend to drift as we explore new relationships with peers and our own identities.

It is probably no surprise that a major research topic in sibling relationships is conflict. Sibling conflict is quite common and, to some extent, can actually be good for children’s development. The sibling relationship offers a unique context for children to develop conflict management skills because, unlike friendships, the sibling relationship cannot just end after a quarrel. Through navigating conflict during childhood, children can learn valuable skills such as understanding others’ perspectives, developing empathy, improving listening skills, setting boundaries and standing up for their own self interest.

However, there is a fine line between small disagreements and conflict being the main feature of the sibling relationship. It is normal for siblings to experience rivalry and competition, but when this becomes the defining feature of the relationship, it can create a negative home environment. Specifically, children can become jealous and start to resent their sibling when they feel the need to compete for their parents’ attention and approval.

How parents can navigate sibling conflict
Although most parents say they don’t play favourites among siblings, up to 85 per cent of children believe their parents play favourites.

One of the biggest predictors of sibling conflict is differential treatment by parents — including perceived differences in parenting. This means that even if a parent believes they are treating all children equally, a child often feels she is being treated differently.

For example, if both children are running through the house on separate occasions and one child receives a time out while the other is not allowed to go to a friend’s birthday party, the second child may perceive this as unfair, and naturally it creates tension in the sibling relationship. Parents should strive to be as fair as possible in their parenting by ensuring consistent consequences for similar misbehaviours among siblings.

Another key factor is for parents to recognize the individual strengths of each child and avoid unhealthy competition between siblings. For example, if one child does well in math, and the other does well in science, recognize their individual abilities and accomplishments and avoid comparing one sibling’s strength with the other’s weakness.

Promoting positive sibling relationships
There are science-backed ways parents can promote positive sibling relationships.

1. Encourage positive engagement: Choose activities and interests that all siblings can enjoy together.
2. Identify what’s going well: Recognize when siblings support, co-operate and help each other.
3. Engage in shared experiences: Highlight each sibling’s unique strengths during activities that require teamwork.
4. Regulate emotions: Help children identify and process their emotions during difficult times.
5. Facilitate social and emotional understanding: Teach children how to share their own feelings and understand and respect feelings of siblings.
6. Manage undesirable behaviour: Address negative behaviours like bossiness towards siblings.
7. Help children learn to consider the actions of their siblings, without assuming these actions are directed at them: It is important for children to understand that accidents happen and siblings often don’t have malicious intent. For example, a parent might see a sibling accidentally knock over the toy tower.
8. Manage conflict: Parents can mediate conflict between children to help resolve situations fairly.
9. Examine parental differential treatment: Talk with children about instances when they feel they are being treated unfairly. Ask them to explain why they think something is “not fair” and discuss it together.

By implementing these strategies, parents can build strong, positive and supporting relationships between siblings, which can support their well-being throughout their lifetimes.

(This article is republished from The Conversation under a Creative Commons license)