Can You Tell Mary-Kate from Ashley? Take Our Quiz and Prove It.

Slate's Culture Blog
Aug. 24 2011 6:11 PM

Can You Tell Mary-Kate from Ashley?

As part of Slates twins issue this week, Barry Harbaugh writes about DNA tests that twins can take to determine whether they are fraternal or identical siblings. He found that most twins who believe they’re fraternal aren't wrong about being dizygotic—it’s the identical twins who are more likely to be mistaken about their twinly identity. When multiples can describe themselves as being "like two peas in a pod," he writes, they almost always end up having come from the same fertilized egg.

That got us thinking about the most famous twins in the United States: Mary-Kate and Ashley Olsen. Despite the fact that they look eerily similar—similar enough to have found fame playing a single character—the pair has always claimed, without citing scientific evidence, that they are, in fact, fraternal twins. ("We were just told by the doctors" that the girls were fraternal, says their dad, Dave Olsen, when reached today by phone. "We never thought about it much. They are good kids.")


Profile writers often cite physical differences to support the claim that they are a dizygotic set. Ashley, for example, is right-handed, while Mary-Kate is a lefty. But it turns out that this is shabby evidence, since about 21 percent of identical twins do not share hand dominance. So in order to further challenge the claim that the Olsen twins are a fraternal pair, we’ve created a quiz to test just how identical they really are.  

Click through to see if you can tell Mary-Kate apart from Ashley—then let us know how you did in the comments.


Quiz compiled by Lauren Hepler.



More Than Scottish Pride

Scotland’s referendum isn’t about nationalism. It’s about a system that failed, and a new generation looking to take a chance on itself. 

IOS 8 Comes Out Today. Do Not Put It on Your iPhone 4S.

Why Greenland’s “Dark Snow” Should Worry You

Three Talented Actresses in Three Terrible New Shows

The Human Need to Find Connections in Everything

It’s the source of creativity and delusions. It can harm us more than it helps us.


Happy Constitution Day!

Too bad it’s almost certainly unconstitutional.

The Ungodly Horror of Having a Bug Crawl Into Your Ear and Scratch Away at Your Eardrum

My Father Was James Brown. I Watched Him Beat My Mother. Then I Married Someone Like Him.

  News & Politics
Sept. 17 2014 2:57 PM ISIS Helps Snuff Out Conservative Opposition to Government Funding Bill
Business Insider
Sept. 17 2014 1:36 PM Nate Silver Versus Princeton Professor: Who Has the Right Models?
Sept. 17 2014 1:59 PM Ask a Homo: Secret Ally Codes 
  Double X
The XX Factor
Sept. 17 2014 1:26 PM Hey CBS, Rihanna Is Exactly Who I Want to See on My TV Before NFL Games
  Slate Plus
Slate Fare
Sept. 17 2014 9:37 AM Is Slate Too Liberal?  A members-only open thread.
Brow Beat
Sept. 17 2014 1:01 PM A Rare, Very Unusual Interview With Michael Jackson, Animated
Future Tense
Sept. 17 2014 12:35 PM IOS 8 Comes Out Today. Do Not Put It on Your iPhone 4S.
  Health & Science
Bad Astronomy
Sept. 17 2014 11:18 AM A Bridge Across the Sky
Sports Nut
Sept. 15 2014 9:05 PM Giving Up on Goodell How the NFL lost the trust of its most loyal reporters.