Here’s Why The Most Successful Couples Look Eerily Alike, According To Science

April 11, 2017

Apparently, we love to look at ourselves.

There’s an oft-repeated story in my ex-husband’s family, about how at his sister’s wedding, the minister initially mistook her fiancé for her brother. It’s not hard to see why; my former sister-in-law and her husband-to-be looked far more alike than she and her actual brother did – and still do.

I always found this story slightly creepy. Who’d want to marry someone who looked like they could be related to you?

Turns out, plenty of people. Statistician Emma Pierson studied dating website eHarmony‘s algorithm, which is designed to successfully match compatible couples. After pouring through results from one million matches, she found that, overwhelmingly, people were looking for partners who resembled themselves.

But why? As usual, science has an answer…

Mirror, mirror on the wall

There’s an old saying that familiarity breeds contempt – but when it comes to choosing a mate, it seems the opposite is true. In a 2010 study published in the Personality and Social Psychology Bulletin, researchers asked participants to rate strangers’ faces according to how sexually attractive they were, and found that people were consistently drawn to faces that looked similar to their own. When the strangers’ faces were morphed with the participants’ faces, 45 per cent of the participants unwittingly rated the mashup that contained their face as the most attractive.

That may not be as irredeemably vain as it sounds. “When you have a face that looks more like you, you tend to trust it more and think it looks more cooperative,” psychology researcher Tony Little, who studies the role of looks in how we choose our mates, told USA Today.  Plus, it may actually be easier for us to see people who look like us: that 2010 study found that our brains more easily process familiar images.

So, it seems that even if you don’t always love what you see in the mirror – the nose you always wished was straighter, the weak chin you inherited from your father – odds are, you’ll seek out those same traits in a partner.

You remind me of someone…

Of course, not everyone chooses a mate who looks like them. But if they stay together long enough, they may end up looking alike anyway.

University of Michigan psychologist Robert Zajonc studied pictures of couples as newlyweds, comparing them with photographs taken after they’d been married for 25 years. He then asked people to sort the photographs according to how much the faces looked alike. Zajonc found that while people didn’t necessarily think that the newlyweds looked alike, they did find more similarities in the long-married portraits. He concluded that a lifetime together does, in fact, morph people into twins – or at least, make them look more like each other.

There are a few different reasons this could be true. One is that couples tend to eat similar diets, but another, perhaps more compelling reason, is that a shared life leads to common experiences and emotions. Grief, joy, and stress all leave their marks on our faces, thanks to facial expressions that shape the muscles and wrinkles around our cheeks and eyes. In other words, laugh lines and crow’s feet could be contagious.

Another theory says that people aren’t searching for partners who look like them, so much as they are looking for someone with similar personality traits as them. LiveScience reports that face shape and brow structure are a couple of the facial features that give us clues to personalities: a prominent chin is linked to a dominant personality (because it’s linked with higher testosterone levels), while people’s smiles and eyes go a long way to indicate whether they’re more aggressive or charming, playful or depressed. Naturally, we tend to gravitate to people with personalities that complement our own.

And they lived happily ever after

The whole choosing-someone-who-looks-like-you thing might seem like just an amusing quirk of science, but there could actually be more to it than that. It might actually affect how well couples do together, long term. (This might be a good time to bring up another cliché: birds of a feather flock together…)

Zajonc’s study found that couples who had similar faces actually reported being happier in their relationships than those who didn’t look like they could be brother and sister. However, this could be a chicken-or-the-egg type of situation: maybe it’s not that couples who look alike are happier together, but that happy couples grow to look more alike over time. So there’s no need to panic if you don’t look anything like your partner.

In fact, there are good reasons for us to choose mates who don’t look like us: humans tend to have healthier offspring when we mate with genetically dissimilar partners. So while we may be more comfortable looking at a face that’s familiar, on a deeper level, we instinctually hone in on partners with a different DNA makeup than our own. In this sense, opposites do attract.

Just remember: whether you and your SO look nothing like each other, or looking at each other is like looking in a mirror, all relationships take work. Don’t assume marrying your doppelgänger is a guarantee of a lasting marriage. (Although my former sister-in-law and her husband did recently celebrate their 30th anniversary…)

Images via tumblr.com, gifwave.com, and hbo.com.

Comment: Do people think you and your partner look alike?


Want More?

Have our best reads delivered straight to your inbox every week by subscribing to our newsletter.



You Said