What Do We Already Know About Sibling Relationships? And What Still Needs to Be Explored?

Although siblings are the building blocks of family structures and key players in family dynamics, research into their roles is still somewhat neglected by scholars. One study illustrated this by examining psychological and sociological abstracts from 1990–2011 with the title “siblings and relationships.” Only 741 citations were found. In contrast, the term “parenting” yielded 33,990 citations, 8,685 for “marriage or marital relationship,” and 5,059 for “peer relationships or friendships.”

Growing Up Side by Side

Research has confirmed that sibling relationships are shaped by individual, family, and external forces. While siblings remain connected during childhood and adolescence, the characteristics of their relationships and roles can change significantly over time. Naturally, this influences the nature and strength of their mutual impacts.

It was also found that siblings from the same biological family are often as different as unrelated individuals. However, detailed documentation of the processes that explain sibling similarities and differences is lacking, as is research into increasingly diverse family and broader sociocultural contexts—including adulthood, when maintaining sibling relationships becomes more voluntary than during adolescence.

Impact on Health

Still, researchers have uncovered some intriguing findings. Dr. Susan B. Sisson, professor of nutritional sciences at the University of Oklahoma Health Sciences, discussed the strength of sibling bonds in an article published by the American Heart Association. She explored how sibling cohabitation affects physical activity levels, eating habits, and the occurrence of obesity. According to her, there is a “pretty strong influence” in this regard.

Dr. Sisson also contributed to a 2019 study on the eating habits of only children versus those with siblings. It revealed that young children with siblings tend to eat more healthily than only children. Moreover, families with more children seem to cook better overall.

This was previously confirmed by a 2017 study, which also showed that children with siblings watch less television and have a lower risk of obesity. However, research involving 326 families with two adolescent siblings pointed out that the quality of the relationship matters. Sibling conflicts were associated with a higher risk of overweight in adolescence. This correlation was strongest in brother-brother and older brother-younger sister relationships and weakest in sister-sister relationships.

Mutual Shaping

Dr. Keith Vakafatu Osai, assistant professor of child and family studies at Weber State University in Utah, noted in an article for the American Heart Association that siblinghood is one of the most enduring relationships in life, and people influence each other both positively and negatively within it.

There are also studies on the psychological impact of having siblings. The Harvard Study of Adult Development, which followed a group of men for 30 years, linked limited sibling relationships before the age of 20 with a significantly higher risk of depression in adulthood.

Good Relationships and Life Well-Being

A recent study published in Social Science & Medicine focused on the long-term connection between sibling affection in adolescence and health and well-being in adulthood. The study examined 1,244 sibling pairs and tracked changes in affection over a one-year period, alongside 32 indicators of physical and mental health, health-related behaviors, social factors, and civic engagement about 20 years later.

The authors concluded that greater sibling affection contributes to better quality of life in adulthood. Love for siblings was linked to better sleep, increased optimism, greater psychological well-being, and more responsible civic behavior (such as a higher likelihood of voting). Love from siblings was associated with lower risk of anxiety and depression.

Editorial Team, Medscope.pro

Sources:

1. McHale S. M., Updegraff K. H., Whiteman S. D.: Sibling Relationships and Influences in Childhood and Adolescence. J Marriage Fam 2012 Oct 1;74(5):913-930, doi: 10.1111/j.1741-3737.2012.01011.x.
2. The surprising ways your siblings and your health may be linked. American Heart Association, April 9, 2024. Available at: www.heart.org/en/news/2024/04/09/the-surprising-ways-your-siblings-and-your-health-may-be-linked
3. Kracht Ch. L., Sisson S. B., Emily Hill Guseman E. H. et al.: Family Eating Behavior and Child Eating Patterns Differences Between Children With and Without Siblings. J Nutr Educ Behav 2019 Nov-Dec;51(10):1188-1193, doi: 10.1016/j.jneb.2019.08.004. Available at: www.sciencedirect.com/science/article/abs/pii/S149940461930973X
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