Same Genes, Different People: A Tale Of Two Twins

I’ve been writing a lot about the complexities of determining how genes influence our behavior. The latest view from the genetics field is that the picture is getting more and more murky with increasing attention given to the multitude of ways in which DNA gets expressed. Despite that, we continue to get bombarded with suggestions that single genes are completely deterministic for highly complex human behaviors, like for example wanting to be a mom (click here for my take on the “mom gene”). The reality is that DNA is important and can be influential – but it is typically far from deterministic and all kinds of experiences can shape how DNA is expressed and have effects that go beyond what resides in an individual’s genome. There is no greater example of that than considering how identical twins can end being very different people even though they have the same DNA. To that end, blogger/editor Heather Morgan Shott (from High Chair Times, one of my personal favorite blogs out there) and her twin sister Erin Diebert graciously agreed to answer some questions on their experiences growing up as twins – and their recognition that they were, in fact, different people.

Note: Not Heather and Erin

1) Were you guys very similar when you were young? Did people confuse you? Were you dressed alike?

ERIN: Heather and I played together a lot before we entered elementary school. My mom dressed Heather and I exactly the same through first grade. After first grade, we chose to dress differently. Some people confused Heather and I.

HEATHER: We had very different personalities from birth. I was very impatient and wanted things the way I wanted them immediately, and Erin was more patient. I was the extrovert, she was the introvert. She worried a lot, and I was more carefree. As we grew older, some similarities did emerge; I suspect it’s a nature vs. nurture thing. Our differences as babies and toddlers were our natural personalities, whereas traits emerged as we got older based on how we were parented. We’re both worrywarts who try too hard to please other people (our mom is impossible to please and very highly strung).  We’re both ambitious (we were raised by a single mother who worked two jobs to support the family).

Our mom did dress us alike until first grade—that’s when we started Catholic school and were forced to wear uniforms. I suspect that she just decided to let us wear what we wanted when we weren’t in the classroom. And indeed we developed our own styles. Erin dresses for comfort, I dress for style.

People have confused us and excessively compared us. In college, we have totally different majors (and therefore different classes) and it wasn’t unusual for a professor to mistake one for the other out on campus. (We went to the same college.) The comparisons started around puberty when Erin became the “chubby” twin. It was awful. She struggled with her weight for some reason, whereas I didn’t and people always brought it up.

2) Did your parents make a point of raising you differently? Did you have different teachers?

ERIN: When Heather and I entered Fourth grade, we were put in separate classes.

HEATHER: We also had very different interest emerge, and those led us in separate directions. I was super immersed in the tennis team and the school paper. Erin was more introverted and spent her time studying. I excelled in English, Erin was excellent at science and math. And frankly our parents were so steeped in marital troubles for most of our childhood, even beyond the time they divorced (we were 8) that I don’t think they gave much thought to the importance of raising us to be individuals.

3) When did you start to notice (or looking back see now) that you were different people (different interests, abilities)?

ERIN: Heather and I knew that we were different very young, however, we enjoyed playing together when we were young. We felt very fortunate to have an instant “play date.”

HEATHER: Our differences were very well defined by the time we hit middle school. I was perceived as the mischievous one (and, OK, I was) whereas Erin was the one who always followed along. For example, one time Erin and I were preparing to be spanked. I decided that we’d both put a book down our pants so that the whacks didn’t hurt. My mom took Erin to spank, my dad took me. Fortunately for me, my dad thought my little trick was hilarious and he removed the book and hugged me. Erin, on the other hand, got whacked twice as hard. I was also the one who was in charge of setting up all the social plans, while Erin followed along. Erin, on the other hand, made sure that we signed up for ACT prep classes, etc. She kept me on track academically—or, at least, much more on track than I would have been at that age left to my own devices. I just wanted to write, I didn’t care about most of the subjects in school!

4) Did you guys try to “deidentify” when you were young? Or during your teens? (Some twins deliberately try to carve out individual paths)

ERIN: We tried to deidentify from fourth grade and older.

HEATHER: Agreed—especially me. I was the rebellious twin.

5) Any other insights on why you are different?

ERIN: Heather is very outgoing and confident. She joined a sorority in college. I’m also outgoing, but can be introverted at times. Heather likes to stay up late. I usually go to bed earlier. I have a medium group of close knit friends. Heather has many friends, some  of which are close friends.

HEATHER: At this point, a lot of our differences have to do with nurture. Erin still lives in the town where we grew up (Columbus, Ohio); I’ve lived on the East Coast for over 14 years.  I like big city life, and she prefers a more quiet existence.

6) How do you think you are very similar?

ERIN: We are both very compassionate and have had to deal with some very difficult issues going up. Our parents got divorced when we were 8. Our father chose to be out of our lives starting when we were in our early pre-teen years.

HEATHER: Agreed, along with a couple of points that I made above.

Thanks to Heather and Erin for sharing their stories and insights! 

Image of identical twins (not Heather and Erin) via

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