Skip to main content

Verified by Psychology Today

Family Dynamics

Why You and Your Siblings May Still Be Rivals

Parental favoritism still has an impact even decades later.

Every parent with more than one child knows about sibling rivalry. Even if you’re not a parent, but are yourself a sibling, you’re almost certainly familiar with this experience. With more and more blended families as part of the relationship picture, step-siblings may also be in your life right now.

We know from birth order research that children in a family take on a variety of roles that may or may not be linked to personality. For example, the oldest child may be the one to emulate most closely the parents and show leadership qualities as well as high needs for achievement. However, this isn’t always the case. Other factors enter into the picture, including gender, abilities, health, and dispositional factors not necessarily linked to birth order.

Complicating the situation further in birth order research are age differences among siblings, the birth order of the parents themselves, and interrelationships among other family members. For example, grandparents may become particularly attached to one child with whom they closely identify; if grandparents have frequent close interactions with the children, they can alter the family dynamics.

Nicholas Sutcliffe/Shutterstock
Source: Nicholas Sutcliffe/Shutterstock

Looking into the relationships among siblings from the standpoint of their tendencies to compete among each other presents a somewhat different approach to understanding not only birth order but also the basic underpinnings of what brings siblings closer together—or drives them apart. When siblings are young and close in age, their interactions take place primarily at a nonverbal level. The older child has a toy that the younger child wants, and no matter how hard parents try to supervise them, there’s bound to be pushing and shoving.

As siblings get older, pushing and shoving are replaced by verbal parries. Teens may become quite sophisticated in their arguments with their siblings, knowing exactly which buttons to push to get the biggest rise out of brothers and sisters.

What lies behind these sibling dynamics is not only competition for the concrete objects they want (toys, clothing, videogames, the TV remote) but the attention of their parents. Alfred Adler, the first psychologist to address birth order and its relationship to personality, described the “dethroning” experience of the oldest child. For at least 9 months, if not longer, the first-born has the sole attention of the parents. Once that first younger sibling comes along, though, the oldest child is knocked off his or her “throne.” Not only do older children have to share their toys but they have to work extra hard to keep getting the affection and attention from their parents.

Although older children have the advantage of being better able to verbalize their feelings, they have the disadvantage of having to give up their long-held position of “single sib-hood.” After getting used to being the one to get the undivided hugs, kisses, and toys from parents and extended family, someone else has come along now who is more demanding. No older sibling, no matter how talented, attractive, or beloved, can compete successfully with a new baby. Not only are those new babies more dependent and in need of care, but they are impossible to ignore when their needs are unmet.

Parents need to be sensitive and resourceful to attend equally to each and every child regardless of whether the children are infants or growing teens. Unfortunately, this is easier said than done and the differential treatment that parents show can come back to haunt their children for decades.

A 2013 article by Purdue University researcher Alexander Jensen and collaborators is one in a growing body of studies examining the way sibling relationships in adulthood reflect perceived favoritism in the childhood home. Via University of Texas Austin psychologist Karen Fingerman’s Family Exchanges Study, sibling dyads and their parents were interviewed by telephone to assess support giving to children along the following 6 dimensions: (1) emotional, (2) practical, (3) communication, (4) advice-giving, (5) socializing, and (6) financial.

To measure favoritism, the Jensen team simply subtracted the differences between siblings on each of the 6 dimensions. The researchers also assessed depressive symptoms and sibling conflict, by asking the children how often they argued and how often they got mad with or annoyed at their sibling. Another key measure assessed how intimate siblings were with each other by asking them how much they go to their sibling for support and whether they felt their sibling really understood them. The offspring were, on average, 23 years old and their parents were in their early 50s.

You might think that by the early twenties, some of the perceived effects of parental favoritism would dissipate but, as the Jensen et al group discovered, even young adults feel the persistent sting of differential treatment by their parents. Same-sex siblings favored by their parents had fewer depressive symptoms than the favored siblings or those who reported receiving equal treatment. The reason this relationship existed, the researchers maintained, is that you’re more likely to be hurt if you're a girl and feel that your parents show favoritism toward your sister than if your sib is your brother.

However, the gender of the parent also seemed to play a role in determining the effects of parental favoritism on young adult depressive symptoms. When fathers sense their child is depressed, they provide more support toward that child. Mothers behave in the opposite way. Sensing her child is depressed, a mother is more likely than a father to give that child support. Jensen et al. believe that parents seem to sense a need to compensate for the way the other parent treats the children so that the favoritism effect becomes neutralized. In a two-parent family, parents equalize the scales of emotional support to their children.

Sibling relationships in early adulthood also seem to reflect, as the researchers predicted, perceived preferences by their parents. The more the siblings felt their mothers showed preference to the other sib, the less intimate they felt toward that sib in adulthood. For fathers, a different picture emerged. Adult children who felt that their fathers gave them less attention felt more distant from their sibs.

Looking at how close siblings were in general, Jensen and his team found that, as you might expect, young adults from same-gender sibling relationships were closer than those from mixed-gender pairings. However, the effects of parental favoritism made for a much-complicated picture, so that even that generalization doesn't necessarily hold up when you consider mother-father differences in parental preferences.

As informative as this study is, the findings are still limited by the fact that the results were obtained after the kids grew up. No one was watching what happened in the home when the kids were little. Nevertheless, we can see even with this limitation in mind that how we feel we're treated by our parents in relation to our sibs influences our mental health as adults.

From another 2013 study, we can see that family dynamics involving parental favoritism seem to carry even further into adulthood well into the midlife years. Purdue University sociologist Megan Gilligan and collaborators asked older adult parents and their middle-aged children to report on parental favoritism and perceptions of tension among siblings. Unlike the Jensen et al study, only one of the siblings participated rather than the sibling pair. However, the results were similar in that perceived parental favoritism predicted adult sibling relationships. This was particularly so for favoritism exhibited by fathers, which seemed to have large negative long-term effects on sibling tension.

How you interpret the upshot of these studies depends on whether you’re the parent or the sibling. For parents, the results suggest that it’s important to continue to monitor the favoritism your children may be perceiving you show. That favoritism can carry well into adulthood if you're not careful. For siblings, you can see that the quality of your recollection of parental favoritism may be affecting you in ways you never before realized.

Sibling relationships are typically the longest-lasting ones of all those you will ever have in life. Getting the most out of them can affect not only your own fulfillment but also the mental health of the brothers and sisters who will grow up and old with you.

Copyright Susan Krauss Whitbourne 2015

Image source:


Gilligan, M., Suitor, J. J., Kim, S., & Pillemer, K. (2013). Differential Effects of Perceptions of Mothers’ and Fathers’ Favoritism on Sibling Tension in Adulthood. Journals Of Gerontology Series B: Psychological Sciences & Social Sciences, 68(4), 593-598.

Jensen, A. C., Whiteman, S. D., Fingerman, K. L., & Birditt, K. S. (2013). 'Life still isn't fair': Parental differential treatment of young adult siblings. Journal Of Marriage And Family, 75(2), 438-452.