Are People Really Attracted To Partners Who Look Like Them?

"Birds of a feather flock together." And no, I'm not just talking about twinning in plaid flannels or Air Force 1s, either — some people physically resemble the people they date. So, here's a question: Are people really attracted to partners who look like them?

The concept of lookalike couples is nothing new. Just look to the countless roundups of celebs who resemble each other, or the Tumblr Boyfriend Twin, for proof. But why do people seem to end up with partners who look like them? Some researchers believe that humans may be hard-wired to be drawn to what’s familiar, and it totally makes sense. Not only that, but the researchers behind a 2010 study published in the journal Personality and Social Psychology Bulletin concluded that our brains are simply able to process familiar images more easily.

According to that 2010 study, people are not only more attracted to people who resemble our parents, but also people who resemble ourselves. Researchers showed the subjects a photo of a stranger morphing either into an image of another stranger or an image of themselves. When the participants were asked to rate those people in terms of attractiveness, they were more likely to choose the individuals who were an amalgamation of a stranger and themselves. For another 2013 study published in PLOS One, people were shown images of their partner’s face that had been altered to include some features either from a random stranger’s face or the participant’s own face. And across the board, both male and female subjects consistently rated the composite that included some of their own features as the most attractive.

That’s not the only research that supports this idea that opposites don't attract, either. Statistician Emma Pierson, who studied 1 million matches made by dating site eHarmony's algorithm, discovered that people are overwhelmingly more interested in people who are similar to them. Based on Pierson's studies, women in particular prefer men who are not only like similar to themselves physically (in terms of traits like height and perceived attractiveness), but also in other ways, like creativity. In fact, across all 102 traits that Pierson assessed, women were more likely to contact people who were similar to them. Women also showed a slight preference for individuals who used the same adjectives to describe themselves, like "funny" and "intelligent."

Pierson, who works for the genetics company 23andme, has been privy to additional research around this notion. Using a combo of DNA from couples' saliva samples and thousands of survey questions, Pierson and her colleague were able to dig deeper into whether or not similar people often pair up. And what they found, once again, is that opposites do not attract — in fact, it's quite to the contrary: Couples were positively correlated for a whopping 97% of the traits they examined. These traits included everything from age to punctuality and personal interests. Athletes tended to couple up with other athletes, vegetarians tended to pair off with other people who don't eat meat, fast food frequenters tended to shack up with others who hit the drive-through often, and even people who err on the side of apologetic tended to end up with other people who say "I'm sorry" a lot.

It’s not surprising that people would seek out partners who share certain traits, because having at least some common ground plays a big part in your compatibility. But what about physical traits? Why would someone be more attracted to a person who has similar facial features, coloring, or bone structure? As it turns out, this phenomenon is super common among many species, including fish, birds, and other mammals, and scientists have a name for it: positive sexual imprinting. Essentially, preferences are “learned” at a very young age, with parents serving as the models of what to look for in a mate. So, while it may seem like we’re pairing off with people who look like us, it seems we actually may be subconsciously attracted to people who resemble our parents (who we also look like, thanks to DNA). Additional research has revealed that people may be attracted to potential partners who come from similar ancestry, and given that ancestry informs many physical traits, that might further explain the lookalike couple phenomenon.

Before you freak out, remember: this attraction is totally subconscious, and it’s based on familiarity. It’s natural to be drawn to what you know, as that breeds feelings of safety and comfort. Besides, Taylor Swift and Joe Alwyn kind of look alike, and they seem to be doing just swell.