About a month into our relationship, my girlfriend and I attended an opening night show together.
Given we were both dressed up for the occasion, I suggested getting a quick picture on the red carpet. It was our first time being photographed as a couple.
She slung her arm around me and we smiled awkwardly while a friend fired off a few snaps on my phone before handing it back and apologizing for not having been able to make the flash work.
As we were ushered inside the theatre, I scrolled through the shots.
The lighting was terrible and we both weren’t looking at the camera, but there was something undeniably satisfying about our aesthetic – a kind of intangible synergy.
“Is it just me, or do we look really, really hot together?” I asked a friend a couple of days later, smugly sliding her my phone.
“Wow. You really do. You guys totally complement each other,” she gushed.
My observation was obviously biased – most couples would argue they look great together – however, there’s a segment of people we’d all agree seem uncannily well matched to their partners … almost cosmically made for each other.
It’s hard to put your finger on whether it’s a compatible energy thing, a similar dress sense, or physical likeness, but you know it when you see it.
Science has many theories on why this happens, but one of the most popular explanations is a phenomenon called “the familiarity effect”, which is based on the fact we tend to develop a preference for things that feel familiar to us.
This is thought to be because the more we’re exposed to something (such as our own reflection), the easier, and thus more pleasant, it becomes for our brains to process it.
In a study published in the journal Perception, people were asked to rate the attractiveness of images of different faces, some of which had been edited to include features that were familiar to them.
Not only did participants consistently give familiar faces higher attractiveness scores, but they also reported finding less familiar faces more attractive after they’d been shown them repeatedly. This may also shed light on why someone we find cute on a first date can become insatiably sexy as we continue to see them.
There’s another, stranger reason for this, too.
Research shows couples quite literally start to look alike when they’ve been together for a long time. And this happens even when they look dissimilar to begin with.
A paper published in PLOS One which examined photos taken of people at the start of their marriage, and then 25 years later, found most spouses had started to resemble one another in the later shots.
It’s a surprisingly common occurrence between couples who’ve been together for years, and it’s likely the result of something called empathetic mimicry, which happens when people who share a strong bond – and consequently experience a higher degree of empathy for one another – mirror each other’s expressions, leading them to develop similar facial musculature over time.
For some couples, this doppelganger effect is so pronounced, you’d be forgiven for thinking they shared the same genes. One only needs to look to Instagram pages like @SiblingsOrDating, or TikToks with the same hashtag, asking users to guess if two people are related or romantically involved.
There are also deeply creepy theories, like the Freudian suggestion we subconsciously seek out mates who remind us of parental figures (one study actually found heterosexual people rated photos of potential partners as more attractive when a picture of their opposite-sex parent quickly flashed across the screen first).
It’s still unclear exactly why we’re drawn to people who seem to physically complement or resemble us. And frankly, I’m not sure we need to take the romance out of it all with science.
At the end of the day, what’s most important is that my girlfriend and I look really, really hot together.