Why Can’t We Be Friends? Resolving Sibling Rivalry
Image: “Two children fighting over a piece of bread” (1803–1809) by Henri-Pierre Danloux (1753–1809). Sotheby’s Paris / Public Domain
When our youngest daughter was born, as a conscientious parent intent on preventing sibling rivalry, I took the advice of a pediatric expert and bought an inflatable Bozo the Clown bop bag toy, an inflatable clown that stood almost as high as our two-year-old. The expert had warned that the first-born might feel displaced by the new baby and jealousy could follow. Bozo the Clown would be our elder daughter’s punching bag, a way for her to safely express her aggressive feelings. Here’s what happened. She eyed Bozo, with his goofy wide smile and orange hair, and ran away terrified. This isn’t to say she didn’t have jealous feelings. Rivalrous feelings can take many forms; outward aggression is only one.
Rivalry between siblings is as old as humankind. As a species, we navigate between a survival instinct that favors resource competition (Darwin’s survival of the fittest) and a survival instinct for connection (Bowlby’s attachment theory[1]). In the animal kingdom, we can well imagine puppies scrambling for their mother’s teat and forcing out the runt. But to survive, the runt needs to remain part of the pack. We humans are not so different. The sociolinguist Deborah Tannen, in her book, You Were Always Mom’s Favorite: Sisters in Conversation Throughout Their Lives, describes how deadly instinctive impulses can be among non-human species:
“Among some bird species, second eggs are laid as back-ups, needed only if the first hatchling dies. If the first hatched chick is healthy and hale, one of its jobs when the second egg hatches is to push the newcomer out of the nest. The second chick’s death is needed to ensure the first chick’s survival.”[2]
Some tadpoles, sand tiger sharks, and other creatures eat their siblings.
But it’s not only food siblings fight over. Competition is a key factor in survival, and children compete for the “non-material food” of love and attention as well. From fairy tales, myths, Greek tragedies, and religious texts, the oldest stories attest that a “poverty of care” can lead to envy and bullying, even murder, among siblings.
Favoritism—extending special support or affection or preferential treatment and advantage to one member of a family—sets up a hierarchy of comparison: “the good one” versus “the bad one”; “the beautiful one” versus “the plain one.” The athletic brother, the smart daughter, the musical child versus their opposite. Parents may try to provide equal support and attention to their children, but children compete to establish their own identity within a family. Each of us wants to be perceived and acknowledged as individuals. Treating each child fairly does not necessarily make them feel special.[3]
Favoritism and its disastrous effects are at the heart of the well-known fairy tale of Cinderella. Her malevolent stepsisters give us the shivers. Greedy, jealous, and narcissistic, they project their feelings of inferiority onto the kind and beautiful Aschenputtel (“The Little Ash Girl” was the title of the Grimms’ version). They label Cinderella with everything they fear in themselves, their inner worthlessness, and torment and belittle her. The psychoanalyst Bruno Bettelheim argued that “the story of Cinderella resonates with children’s unconscious fears and desires related to sibling rivalry, as the protagonist’s degradation and perseverance mirror the internal struggles many children experience when they feel overshadowed by siblings.”[4] Tannen writes: “In families with more than one child, each additional child necessarily limits the available resources—time and attention as well as money. Limited resources make competition inevitable, and whenever there is competition, it makes sense to try to weaken or even eliminate rivals.”[5]
Fraternal envy and rivalry and their deadly consequences are the core of the Biblical story of Cain and Abel. Cain, the eldest, is a farmer, and brings the best of his crops as an offering to God. Abel, a shepherd, offers God the best lambs from his flock. Abel’s offerings please God, but Cain’s offerings are rejected. In revenge, Cain invites his brother into the field and kills him. God punishes Cain for the murder of his brother by condemning him to wander the earth as an exile and fugitive.
Divorce can also be a factor in creating a division among siblings. One child may become “father’s best friend” while the other child may align with her mother. The parents’ altercations and alienation from each other form the battlegrounds to which side the siblings pledge their allegiance.[6]
The good news is that there are now many structured programs for resolving sibling rivalry. An important first step to stop sibling aggression and abuse is for professionals and practitioners to educate themselves on the differences between normative and harmful sibling behavior. Parents may find mediation techniques helpful when dealing with sibling conflict and minor aggression. A mediational approach, however, is not appropriate when sibling abuse is present. Some parents and children may not recognize that a sibling’s behavior is abusive, so routine screenings for violent, coercive, and harmful sibling behaviors are critical. [7]
Human relationships are not static and unchangeable. Whatever your childhood experience or your experience as a parent refereeing sibling rivalry, it’s never too late to transform the underlying issues at the root of alienation from a brother or sister. Is now a time in your life to seek reconnection? What was your experience with your sibs? Was there rivalry? How did it manifest? Has the rivalry continued over time? What is your vision for a harmonious relationship? What has to change in your attitude or the attitude of your sibling? How can your differences be a source of wonder and joy?
[1] McGarvie, Susan, “Attachment Theory, Bowlby’s Stages & Attachment Styles,” Positive Psychology, 28 November 2024.
[2] Tannen, Deborah, You Were Always Mom’s Favorite: Sisters in Conversation Throughout Their Lives, Random House, 2009. p. 15
[3] Steffgen, Sarah, et al., “’They always disfavor me!’: Parental conditional regard undermines teenage sibling relationships through raising competition and perceived disfavoritism,” Journal of Research on Adolescence, 8 September 2025
[4] Bettelheim, Bruno, The Uses of Enchantment, Random House, 1975. p. 236.
[5]Tannen, Deborah, op. cit., p. 15
[6] Sulloway, Frank, “Birth Order, Sibling Competition, and Human Behavior,” Conceptual Challenges in Evolutionary Psychology: Innovative Research Strategies by Harmon R. Holcombill, Springer, 2001.
[7] Tucker, Corinna Jenkins, et al., “Resources for Professionals and Parents to Improve Sibling Relationships,’ Sibling Aggression and Abuse Research and Advocacy Initiative, University of New Hampshire, Spring 2023
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