Why do couples look alike? The truth behind the theory
Have you and your partner ever been mistaken for siblings?
It may seem like an elaborate insult, but there is actually an abundance of science to answer the infamous question… “Why do couples look alike?”
Brad Pitt might be infamous throughout the years for morphing himself to look like the person he’s dating (the Gwyneth comparison is a perfect example), but aside from fashion choices—is there any truth in the similar soulmate theory?
“While there is some evidence to support the idea that couples might look alike, it’s not a universal truth or a prerequisite for a soulmate,” says Laura Caruso, licensed therapist and relationship expert.
“Relationships are complex and influenced by a myriad of factors beyond mere physical appearance. The concept of soulmates is more richly defined by emotional compatibility, shared values, and mutual respect than by how much two people resemble each other physically.”
It may not be a direct indicator of soulmate status, but we think it’s time to get to the bottom of the theory once and for all. Let’s get into it.
Is it true that soulmates look alike?
“They’re just not my type.”
Beyond the ‘tall, dark, and handsome’ response—are we actually looking for someone who looks like us? We might list different eye colors, hairstyles, or personality traits, but does our soulmate quest really center on finding someone who looks like us?
“The idea that soulmates look alike, while quirky and seemingly coincidental, might actually have some basis in psychological research,” says Caruso.
“It’s important to note, though, that sharing resemblance is not a definitive rule for all relationships, and certainly can’t predict compatibility—let alone determine if two people are soul mates.”
While we may all joke about “siblings or dating” in popular culture, there is extensive research into the phenomenon that might change your perspective on physical similarities between partners. Leaning on the studies of Freud, research revealed that beyond the awareness around incest avoidance, people find individuals who resemble their kin more sexually appealing.
“This phenomenon, often referred to in the scientific community as “assortative mating,” suggests that people are attracted to those with physical, and sometimes genetic, characteristics,” says Caruso.
This might seem a bit icky when you linger on it, but studies have shown that facial attractiveness positively correlates with familiarity and typicality. Simply put, familiar faces bring us comfort, so we view similar facial features as attractive.
And what face do we see the most? Our own!
According to another study, people found faces that most strongly resembled their own faces to be the most attractive, which affected their choice of romantic partners.
“Researchers at Stanford University dove into this phenomenon and discovered that couples often do resemble each other quite a bit,” says Caruso.
“Their study suggests that we might be programmed to be attracted to people who look like us. Their findings indicate that facial similarities among couples could be driven by subconscious preferences or even evolutionary cues that point to the benefits of pairing with someone with similar genes.”
There are a few factors that might contribute to this pattern:
Subconscious preferences for familiarity make a similar-looking person feel safer or more trustworthy.
Similar environments and backgrounds, which influence both appearance and genetics, tend to bring similar people together.
Shared experiences can make them appear more alike over time, both in terms of physical appearance (like dressing similarly) and in behaviors and mannerisms.
What does it mean when couples look alike?
A lot of people might scoff at the concept that all couples look alike as if we’re all on first dates with our döppelgangers.
However, while the phenomenon isn’t all-inclusive, diving into why couples look alike can be a very interesting journey—especially if you’ve been mistaken for siblings before!
"When couples look alike, it’s not just a quirky coincidence; it actually reflects a fascinating intersection of psychology, genetics, and social factors,” says Caruso.
“People often choose partners who are similar to them, whether it’s in looks, background, or habits. Over time, couples might start to mirror each other’s gestures and expressions, or their shared lifestyle—like the foods they eat, the activities they enjoy, or the products and beauty routines they follow—can subtly make them look more similar.”
Therefore, while you may not look alike at first, certain similarities have drawn you together. You may think it’s all just coincidence, that you just happened to go to the same college, or work in the same job, or run into each other at the same bar… Sounds eerily similar to soulmate theories if you ask us.
Aside from all this speculation, displaying similar behaviors (also known as mimicry) is actually a great indicator of your relationship.
“It’s far deeper than simply coordinating outfits on holidays; starting to look more like your partner is a sign of how closely intertwined your lives have become, both inside and out,” says Caruso.
“It’s a small, outward sign of a much deeper bond. Basically, it means you’re doing great!”
Why do couples often start to resemble each other over time?
Ah yes, the transition into being “we people”.
Jokes aside, when you spend a lot of time with your loved ones, you naturally start to become more alike. This goes all the way from a more basic level, such as daily habits or foods, but also to body language or the phrases you use.
“Over time, couples often adopt similar lifestyles, diets, and routines. This can lead to changes in physical appearance, such as weight, skin condition, and even muscle tone,” says Caruso.
“For example, if both partners start a new exercise regimen together or become vegan, their bodies and overall health may reflect these changes similarly.”
Looking through the photo albums of a long-term relationship, many people notice this transition over a long period of time. Whether it’s through their body language, similar facial expressions, or even similar wrinkles—it’s not just a coincidence.
One study by Robert Zajonc attempted to prove this phenomenon by analyzing why cohabiting married couples start to resemble one another over time. This study revealed there is indeed an increase in apparent similarity after 25 years of cohabitation, with couples who witness this convergence experiencing a higher relationship satisfaction overall.
This isn’t just exclusive to old couples, with many relationships engaging in ‘mirroring’, which also indicates your feelings for one another.
“One of the subtle yet powerful ways couples grow to resemble each other is through mirroring,” says Caruso.
“This includes mimicking facial expressions, gestures, and even speech patterns. Such behaviors are often unconscious and serve to enhance emotional connections and empathy between patterns. Think of mirroring as internal software that’s been programmed to deepen your relationships.”
So, if you’ve ever been mistaken for siblings, or teased that you behave like twins… Take it as a sign that your relationship is on the right track.
