“Identical” Twins Are Less Identical Than We Thought, But Still Just As Creepy

by Tom Limo

If you’ve been jonesing for some news on twins—the creepiest kind of people there are—this story should give you your fill: According to CNN, researchers in Iceland have discovered new genetic differences that begin at the early stages of identical twins’ embryonic development, marking a stark difference in their molecular makeup.

So interesting. You and your twin might be best friends and look super similar, but you can actually still be pretty uniquely creepy in your own ways!

Scientists have long used identical twins to study the effects of nature verses nurture. For decades, the accepted scholarly opinion has been that, because they share the same genes, any physical or behavioral differences between such siblings must be due to outside forces.

But, as suggested by the new research in Nature Genetics, that may not be the case.

In any embryo, cell division can lead to mutations, but this type of genetic difference hadn’t been studied in identical twins. Why? Likely because doctors were too disturbed by doppelgängers, and don’t wanna go anywhere near that shit.

Over the course of a four-year study, a team of Icelandic researchers at Decode Genetics found that identical twins forge genetic differences in these early stages of embryonic development.

“We found a pair of identical twins where a mutation was found in all cells in the body of one of them but was not present in the other twin at all. Then we found twins where a mutation was found in all cells in the body in one twin, but in only 20% of the cells of the other,” said Stefansson, the founder and CEO of DeCode Genetics.

So cool. I guess it just goes to show that even though basically every twin has the same-sounding voice and wears really similar clothes — not to mention almost always has the same group of friends and collection of interests, even as adults, in a way that grows more and more unsettling as the years go by — they actually start out as genetically very different, and even have the potential to not seem totally interchangeable in just about every setting.

That’s such a wonderful message to take away from all this. No matter who your siblings are, or how similar they are to you in essentially every way, including how people shiver when seeing you side-by-side with your identical sibling, we’re all totally unique from a scientific standpoint.