Dear Patti,

I’m a twin. Five years ago I went to a weekend conference about twins and met my husband, Peter, who is also a twin. Peter doesn’t like being a twin and values his individuality above all else. Growing up, he felt his mother just loved the attention from having twins. He has no contact with his brother, which I find very sad. He doesn’t hate him but he felt invisible growing up because he was always compared as “second best” to his brother. Peter said his brother often took credit for things he did and their parents viewed his twin as the smart one. He only got positive attention when his twin wasn’t around. As an adult, Peter shut his brother out of his life. 

In contrast, my friend Evie and her twin sister (now in their 50s) are inseparable. They live together, often dress alike and have the same friends. They even answer for each other when asked a question. They enjoy the attention they draw from being twins and Evie says she doesn’t know if she could function without her sister.

My twin brother is wonderful and I’ve always been grateful for his emotional support. I’m really happy to be his twin. While I feel like we’re uniquely close because of our twinship, we happily live our own lives. In many ways we’re similar and in other ways very different. To me, that is all great. 

I was just curious about the fact that even though we’re all twins, my husband, my friend and myself have very different experiences.

  — Olivia 

Dear Olivia,

Yes, it’s true that many people have very different experiences being twins. While all twins have their own individual experiences — in part due to varied environmental realities — four very distinct patterns of twinship have been identified: unit identity, interdependent identity, split identity and individual identity. 

Unit identity is when the twins’ identity are shared with each in such a way that they feel they cannot exist without each other. They often have parents who are limiting and psychologically abusing and, consequently, turn to their twin for support and are unable to survive emotionally without each other. Unit identity twins are able to live productive lives but tend to have intense difficulty forming relationships with others, extreme co-dependency with their twin and may never obtain individuality.  

Interdependent identity exists when the siblings believe their co-twin is more important to them than their parents. Twins with interdependent identity often had parents they felt unloved by and become very involved with the love and acceptance of their twin as a replacement for the missing parent-child bond. Separation from one’s twin can, therefore, be extremely difficult. They trust their twin above all others. Interdependent twins often have similar careers and lack a desire to form other friendships. Their co-twin identity is more important than their individual identity. 

It sounds like your friend Evie and her sister might fall under one of these categories.

The third pattern of twinship is split identity. This is when parents are excited to have twins and revel in the attention the twins attract. These parents often label one twin as “good” and one as “bad.” It’s common for the siblings to have a conflicted relationship with one another as well as shame associated with being a twin. These twins tend to go their separate ways as adults. Unfortunately, they also tend to hold on to their parents’ labels. The good twin may have grandiose expectations of oneself, while the bad twin may become too self-critical. Peter and his twin may fall under this category.

The last pattern of twinship is individual identity. This is when the twins are raised to be individuals and expected to function separately. They have intense attachment to their co-twin but also have the ability to form strong attachments with others. As they age, individual identity twins tend to measure themselves against one another but are very supportive when their twin needs help. These twins tend to function successfully in their careers and relationships. This pattern is common in fraternal boy-girl twins because parents naturally treat them differently based on gender.

Although there’s variation and not all twins will fall neatly into one of these four categories, as twins you may find it helpful to understand these common patterns. 

Patti Carmalt-Vener, a faculty member with the Southern California Society for Intensive Short Term Psychotherapy, has been a psychotherapist in private practice for 23 years and has offices in Pasadena, Santa Monica and Canoga Park. Contact her at (626) 584-8582 or email Visit her website,