November 15, 2021

November 15, 2021

How Siblings Can Affect Brain Development

For many people, having more than one child is a way to ensure your children grow up with a friend by their side. Siblings can play together and keep each other entertained when you’re busy, or just help each other out as they continue to grow older. When it comes to scientific reasons why having a sibling is a good thing, research shows that people with close bonds to their siblings end up happier as they age and are more likely to experience better overall health.

While it’s true that there are several differences in development between only-child homes and those that have more than one kid, some of the benefits and downsides are related directly to brain development. But how does having a sibling affect the development of the brain? And is it more beneficial to grow up with one or more siblings in the home?

How does family impact brain development?
The type of family life a person has from childhood has a great impact on their development in many areas. For example, one study found that a child from a home with family problems is far more likely to have mental health issues later on in life. The study used imaging technology to examine and determine the state of the brains of teenagers aged 17–19. The teens who had dealt with family problems before the age of 11 had smaller cerebellums, which is the area of the brain that regulates stress, controls sensory-motor skills, and plays a role in skill learning. It was also posited that having a smaller cerebellum could correlate with the development of a psychiatric illness.

Since the development of a child’s brain is closely tied with their experiences with other people, the way a family interacts has a direct connection to how well a child develops. This is especially true in the first eight years of a child’s life, according to the Centers for Disease Control and Prevention. This means that generally, children who come from stable and loving homes, with parents who have good relationships with each other and their children, are more likely to develop much-needed skills to lead healthy lives as they grow into adults. On the other hand, if a child is neglected and under chronic stress from a tough home life, their brain development can suffer greatly.

How does having siblings affect your brain development?
Siblings play a large role in children’s lives from birth. When a child has a sibling around, they gain a by-default companion, confidant, and combatant. Their relationship with their siblings is also a basis for how they compare social interactions with the outside world. Research shows that siblings serve as social partners, role models, and influences that can help drive brain development from a child’s early years. The impacts these relationships have depend on many factors, such as whether or not a person is the older or younger of the siblings, how the family dynamic is from the start, and the genders of the siblings.

The first part of brain development that is affected by having a sibling has to do with the shaping of relationships. During the formative years of a child’s life, they will learn how to have relationships with others from those around them. Studies have found that younger and older siblings benefit in different ways. For example, younger siblings are often able to teach their older sibling how to practice empathy.

Studies looking at only children have also found that there are differences in brain development between those with siblings and those without. One particular study looked at the volume of grey matter in the brains of children with and without siblings, finding that there were stark differences between the two. Only children had more volume in a portion of the brain that is associated with language processing and perception, whereas children with siblings had more volume in the parts of the brain associated with emotional regulation. These changes in brain structure paint a picture as to why children without siblings have different behaviors as they age compared to those with siblings.

The same study showed that although there was no evidence of either children with siblings or only children being less or more intelligent, those who grew up without siblings were found to have greater flexibility in thinking. However, only children were found to be less agreeable.

How do siblings affect cognitive development?
According to a dated study published in 1991, socialization of younger siblings is often driven by the influence of the older child. The study also says that siblings are more influential than peers when it comes to cognitive development because of the unique relationship that is built by children growing up together.

Newer studies have looked at how cognitive development is influenced by siblings, and found that the effects of siblings on child development were more beneficial for the younger sibling. One specific research paper published in 2013 looked at how older siblings contributed to a child’s cognitive skills and found that they often play a role in learning by acting as a third parental voice in the household. In fact, learning certain subjects such as math or language were directly affected by having an older sibling, which has a lot to do with processing and retaining new information. The gender of the older sibling was also a factor; the same paper shows that older brothers have more of an impact on younger siblings’ mathematics skills, while older sisters play a more direct role in the development of language skills. 

While having a sibling may be seen as difficult at times (especially for children who don’t always get along!), there is no denying the clear benefits of being raised with a sibling, and the fact that siblings are good for brain development in general.

Featured image by Chayene Rafaela on Unsplash