Sisterly Love: Reflections on Twinship

Identical twins are fascinating, not only to their parents but also to the public. On a daily basis, people on the street inquire about my daughters, from elementary school kids who assert, “They look like the same person!” to adults who say, “I always wanted to have twins.”

At almost five-years-old, M. and S. know they are twins, but they have only a vague understanding of how that relationship differs from other sibling relationships. Recently, as S. signed her name one day, she told me:

“S-A-M, that spells Sam.”

I asked, “Do your friends at school call you Sam instead of Samira?”

“No,” she replied. “They call me [M.]”

“Why do they do that?”

“Because they’re silly.”

S. thinks her friends are silly because she does not believe she and her sister look alike. Indeed, not all twins do, with fraternal/sororal twins (originating from separate fertilized eggs) being the more common type of multiple. My husband and I believed our daughters were sororal twins until they were six months old because that is what our obstetricians told us they were. Our girls were “di/di” in utero, which means that they had separate amniotic sacs and separate placentas. Most “di/di” twins are fraternal/sororal, while many identical twins share a placenta and possibly even the amniotic sac.

When our girls turned out to have the same recessive blood type and red hair color (a surprise to the South Asian side of the family), people started asking us if they were identical. So, we shelled out a fair amount of money for a DNA test to tell us what we seemed incapable of realizing for ourselves: “[T]here is greater than a 99% probability that the twins are monozygotic.”

Without that piece of paper, I might have been living in denial today — I have seen more than a few examples of parents being the last to know that their very-similar-looking twins are identical. As parents, we are attuned to seeing small differences in our children’s appearances, and so we make ourselves believe that differing birthmarks and slight differences in weights or heights are irrefutable signs of different underlying genes. The truth is that so-called identical twins aren’t really identical in every way, one of the many interesting aspects of twinning/twinship.

For those who are curious about this special sibling relationship, I recommend reading Abigail Pogrebin’s One and The Same. This non-fiction book is a mixture of memoir and interviews, a compilation of Pogrebin’s reflections on her own experience as an identical twin, profiles of other sets of twins, and conversations with experts on the science behind, and social aspects of, twinning and twinship. It is a well-researched, intimate look at the twin relationship that delves into the positives of closeness to the negatives of comparisons, competition, and loss. The book explores, for example, how some twins seek to enhance the sameness, while others struggle to differentiate themselves, sometimes to an extreme degree. Monozygotic twins may share the same underlying genes, but how those genes interact with the environment creates individuals who can be, in some cases, as different from each other as any other set of siblings.

This book has influenced the way my husband and I are raising our daughters. We treat them as two separate people who happen to look very much alike. Thus, we encourage them to wear different clothes, have different friends, and engage in different activities, while also encouraging them to spend quality time together and to cherish their sibling bond (without excluding their baby sister).

So far, M. and S. perceive themselves as individuals, and hopefully the rest of the “silly” world will recognize their individuality, too.