We all know the age-old adage, opposites attract - but according to new research, we are in fact, also attracted to the like. Yes, people being attracted to those who physically resemble them is a very real phenomenon, and there's a scientific explanation behind it.
If you've ever watched The Vampire Diaries, you'll be familiar with the term doppelgänger: a German word referring to a lookalike, or double, of a living person, despite the two being biologically unrelated. A play on the term, 'doppelbanger', is also used colloquially to describe couples who look alike or have more than a passing resemblance to one another.
In a new study published in Evolution and Human Behavior, researchers from the University of Queensland in Australia recruited 682 heterosexual participants and recorded 2285 speed-dating interactions. About half of the interactions took place between partners of the same ethnicity, while the other half were between partners of different ethnicities.
The participants interacted in three-minute rounds of 'speed dating' before completing a questionnaire to rate both the facial attractiveness and perceived kindness of their partner.
The researchers found that people with similar facial features overall found each other more attractive than those with different physical characteristics. People of the same ethnicity were also more likely to find one another attractive, compared to those of different ethnicities.
When it came to perceived kindness, those with similar facial characteristics also were more likely to view each other as more kind - regardless of ethnicity.
"Some have proposed that long-term shared lifestyles result in a convergence of physical likeness, but there is mixed evidence regarding this possibility," the researchers said.
"Alternatively, facial similarity in couples could be the result of a preference for facial similarity in a romantic partner."
The researchers noted that the preference for similar facial features and structure could be due to the sense of familiarity, which is associated with feelings of comfort, kinship, intimacy and belonging.
The study also found that facial features typically considered 'more masculine' - think a strong jawline - had positive connotations in terms of male attractiveness, but negative connotations for women.
The authors said their findings suggest there is "a genetic basis for what kind of faces we find attractive" and "preferences for certain facial features potentially evolved due to fitness benefits signalled by those features".
This is not the first study to find that we're essentially attracted to our own features (we're all narcissists, apparently). According to research reported in the July 2010 issue of Personality and Social Psychology Bulletin, we're not only attracted to people who resemble ourselves, but also our parents.
In one study, a picture of a stranger was morphed with a picture of the participant or a picture of another stranger. When subjects were asked to rate the attractiveness of each picture, they usually picked the people who were an amalgamation of a stranger and themselves. The research also found people consistently preferred faces that resembled their parents, suggesting the tendency to couple with a 'doppelbanger' stems from a desire to repeat the first relationship we were exposed to as children: that of our mum and dad.
In a 2013 study published in PLOS ONE, people were shown edited images of their partners' faces that included features from either a stranger's face, or their own. Overall, people consistently preferred the edited face that more resembled their own.
A study from 2017 in PLOS Genetics looked at gene similarities in white couples and found many had shared ancestry. The researchers suggested this was likely due to the factors considered when picking a partner: think social class, nationality, ethnicity, religion, and anthropometric traits such as height and weight. In other words, the findings indicated we may see couples who resemble one another because we subconsciously gravitate to people with a similar upbringing and values, which in regards to shared ethnicity, can lead to shared ancestry or genes.
