Adult Twins: Identity, Rivalry, and Intimacy

adult twinsSome twin pairs, not all, become disillusioned about their twinship because they struggle to be “known,” not just “noticed.” Since outsiders habitually relate to them as a unit or a fixed dyad, they expectedly have conflicts with their twin in an attempt to define or declare their individual selves. While twins fight just like different-aged siblings, their tensions have much more to do with establishing separateness and uniqueness, traits afforded naturally to siblings born at different times.

Twins, especially identical twins, appear to harbor more resentment toward one another as they get older because they have worked diligently to establish a balanced and harmonious relationship over the course of their lives. They have both invested in this balance out of a need and wish to regulate competition and comparison. As their lives diverge, it becomes much more difficult to maintain a sense of equality and sameness. When this occurs, one twin might find it difficult to enjoy her work or relationship successes because she feels guilty about disrupting the balance with her sister. I have worked with many twins who feel as if they are betraying and abandoning their twin when their life paths diverge and change. Their loyalties to one another are strong—while admirable, it makes separation much more difficult. Rivalry in adult twins has everything to do with wanting to be on one’s own and discovering one’s singular sense of self without worrying how this will disrupt and upset one’s twin.

My work with twins has also highlighted why they have difficulty handling conflict. Rather than agreeing to disagree or being capable of hearing their twin’s perspective, they are more driven to win rather than compromise. I believe this lack of emotional maturity results from the fact that they are still struggling to come to terms with their individual identities and therefore are still fighting to beat their rival rather than respectfully accept their differences. Isn’t it ironic that twins who are perceived as soul mates and “best friends forever” often have difficulty with the most basic concepts of intimacy—compromise, empathy, and acceptance of differences?

The deep dependency issues that naturally evolve growing up as a twin also fuel twin rivalry. So often twins are “crippled” because they have not mastered developmental milestones as singletons.

They go to sleep, go to school, socialize, and study with their twin. While this togetherness has definitive benefits, it can also interfere with each twin’s capacity to be resilient and independent. By the time twins go to college, they are expected to be capable of handling many life tasks as an individual. However, without any prior planning or preparation, they are understandably ill equipped to handle many situations on their own.

Most twin pairs eventually find ways to repair their relationships and mitigate their rivalry as they find and define their individual life paths and identities. If you have a story about a twin rivalry that improved over time, please share it in the comments section.



The image in this post is courtesy of D. C. Atty via Flickr (CC BY 2.0 license).



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  1. Thelma Cartwright

    My twins are nearly 34 and really do not get on , one is continually interfering in the other’s relationship and will not accept that the interference is not helping . She won’t accept that she is wrong by interfering and will not tolerate any discussion to try to resolve their issues . There’s more too

    • Dear Thelma,
      I realize how frustrating this must be for your family.
      I would recommend buying a copy of my book The Same but Different because it will help you understand why your daughters are behaving this way.
      Also perhaps you want to contact Audrey Sandbank – she is a psychotherapist in the London area who has worked extensively with twins
      Her email address is

  2. Mary Hayden

    I know that my experience is how other people treat twins have caused problems between twins from the very beginning. They feel like they have to choose one over the other. Treat you like one person even using one name . Buy things and expect them to share when brothers and sisters have their that one is favored by friends ,relatives ,church people,teachers until one feels like they are not wanted or they are nothing to anybody giving the favorite twin a big head and controlling attitude take everything away from the one everybody hates. People make them feel like they have a right to treat their twin rudely and mean .play tricks to hurt their twin. I am a twin that twin that is left out.

  3. J

    I grew up with two older brothers and a girl fraternal twin. We shared a room growing up and yes had “fights” and we’re in the same class at primary school. Know as the “twins” my sister was shy so I did a lot of the talking until she gained her confidence. Report cards were compared and my mother said I should be more like my sister… We started having different friends and were separated at intermediate. At high school it was hard. We were at an all girls school, put in different class rooms but competed to get in the reserve A netball team. While my sister cruised into the team at 5ft 10. Plus, at five foot 6, it was harder for me in the wing positions to make the team but I did it. I could not study some sciences because my twin was in that class, and though she would have swapped the school wouldn’t let that happen. So I was stuck doing biology only and this changed my academic / job outlook, but I did get top of the class in biology.. yes bullying from her friends on a trip when I had none of my own friends on happened and no she did not stick up for me, I didn’t need her anyway. We used to walk home separately too in high school. The relationship improved when we got jobs.
    Yes, I felt like in the family I was the the spare and not a very good one.
    The boys chased my sister for her for her height etc and as a teenager I felt invisible.
    I ended up leaving and going overseas. I see the family every so often but the distance I guess that experience has been really good.
    When I am home walking beside my twin I’m reminded how tall and slim she is, but like she can’t help that, when I had mentioned this to my mum she is 5ft 2 she said “well how do you think I feel?” My twin was given my mother’s middle name, so really it was decided at birth that she was the favorite from us girls. It is what it is!

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