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"The role of siblings goes far beyond childhood power struggles or alliances over who gets to control the TV remote," says psychotherapist Ilene S. Cohen, Ph.D., who teaches in the Department of Counseling at Barry University.
"Siblings often serve as emotional mirrors. Through them, we learn how to manage conflict, express empathy, compete, collaborate, and reconcile. Unlike parent-child relationships, sibling interactions are horizontal rather than hierarchical, creating a space for children to practice interacting with equals."
From a Bowen Family Systems Theory perspective, siblings form the bedrock of each other's social and emotional development. "They are our first peers, and these relationships provide the framework for how we interact with the world," Cohen says.
"Whether we lean toward cooperation or competition, sensitivity or distance, or develop a leadership style versus a more passive role, much of it stems from the unique dynamics we experience with our brothers or sisters."
Many of these memes poke fun at personality traits siblings develop based on birth order, a subject that researcher Walter Toman explored as well.
His work indicates that firstborn children often take on leadership roles, displaying qualities such as responsibility, organization, and a desire to please authority figures.
These traits usually develop because older siblings are often expected to set an example for their younger siblings. Conversely, later-born children, such as second or third children, may develop characteristics that contrast with those of their older siblings.
According to Toman, middle children, in particular, have a unique position within the sibling hierarchy. They often feel “sandwiched” between their elder and younger siblings, and this can lead to distinct personality traits.
They tend to be peacemakers, highly adaptable, and sensitive to the environment around them. Middle children often develop skills related to negotiation and compromise as they navigate the varying expectations and roles established by their siblings. This adaptability helps them become more independent and resourceful.
However, they may also exhibit traits of rebellion or nonconformity as they strive to carve out their own identity in contrast to the established roles held by their elder siblings.
Youngest children, on the other hand, develop personalities shaped by growing up with older, more established siblings. These folks are typically more flexible and socially skilled because they had to adapt to family dynamics that were already in place before they were born. Youngest siblings may be less inclined toward traditional leadership roles and instead excel as collaborators or supporters, often using charm, humor, or creativity to gain attention and assert themselves.
"When siblings act as allies, they buffer the stress of difficult childhood experiences," Cohen adds. "Siblings often 'co-parent' one another in family systems where parents are emotionally unavailable, creating informal caregiving roles that may later inform professions or partnerships."
"Siblings are usually present for milestone moments, ranging from weddings to funerals, and their shared experiences form a unique repository of familial history."
