From Kirsten Dunst and Jesse Plemons to Justin and Hailey Bieber, many celebrity couples could easily pass as siblings.
Now, a study has revealed that this is no coincidence.
Scientists from the Korea Advanced Institute of Science and Technology have confirmed that women fancy men who look like their brothers.
To find out what people look for when rating potential partners, the experts analysed the interactions between more than 40,000 people on a major online dating platform.
Using AI tools, the researchers were able to measure how similar users were in both facial features and personality traits.
The results revealed that women have a ‘clear preference’ for men who look more like them.
While the reason for this remains unclear, the researchers point to the ‘parental investment theory’.
‘[This] suggests women tend to prioritize cues of trustworthiness and familiarity to mitigate the risks associated with partner selection, for which facial resemblance may serve as a heuristic,’ they explained.
From Kirsten Dunst and Jesse Plemons (pictured) to Justin and Hailey Bieber, many celebrity couples could easily pass as siblings. Now, a study has revealed that this is no coincidence
Scientists from the Korea Advanced Institute of Science and Technology have confirmed that women fancy men who look like their brothers. Pictured: Justin and Hailey Bieber
While beauty is in the eye of the beholder, the researchers set out to understand what men and women tend to look for when rating potential partners online.
The team enlisted 41,441 participants aged 18–47, who used a popular South Korean dating app.
Using AI, the team analysed a total of 506,014 interactions betewen these users.
The results revealed that when it comes to facial features, women prefer men who look like them.
In contrast, men prefer facial dissimilarity – rating women more highly when their features were unlike their own.
‘This result is consistent with the evolutionary logic of inbreeding avoidance,’ the researchers explained in their study, published in Computers in Human Behavior.
‘Attraction to dissimilar faces may be an evolved mechanism to avoid genetic costs and increase the genetic diversity of offspring.’
Meanwhile, when it came to personality similarity, socio–economic status (SES) was found to be the most important deciding factor.
The results of the study revealed that when it comes to facial features, women prefer men who look like them. Pictured: Rooney Mara and actor Joaquin Phoenix
When their personalities aligned, women rated high–status men even more positively.
However, the men rated high–status women less favorably when their personalities were similar.
According to the researchers, this suggests a ‘status imbalance’.
‘Given that the traditional male gender role is associated with resource provision, a partner’s higher SES may signal a deviation from this script,’ the researchers explained.
‘In such contexts, the relevance of intimacy–building traits like personality similarity appears to be diminished.’
Looking like your partner is of course not a new phenomenon, with a popular Instagram account actually dedicated to the concept.
@siblingsordating has more than one million followers, as it asks social media users to guess whether pairs are blood–relations or lovers.
Some of the couples share almost identical features, while other snaps show family members who have snuggled up in poses which are a little too close for comfort.
If you’re dating someone who looks JUST like you then you’re in good company with celebs like Kristen Stewart and Courteney Cox
Rather than opposites attracting, studies have long shown that people are more inclined to date partners who resemble themselves.
Celebrities around the world are proving the notion – including blonde bombshells Oscar–nominated Kristen Stewart and her fiancée Dylan Meyer.
Meanwhile, Friends star Courteney Cox and her partner Snow Patrol guitarist Johnny McDaid are noted for their incredibly similar face shape and bone structure and piercing blue eyes.
But the phenomenon is not exclusive to the rich and famous – an Instagram page called @siblingsordating is dedicated to snaps of couples who appear eerily similar.
It may be that we are innately drawn to other people who look like us because seeing them sparks a feeling of familiarity or kinship.
Human rights lawyer Alexi Ashe and her husband comedian Seth Meyers attend the 2023 Met Gala in New York City
A study by Institut des Sciences de l’Evolution, in Montpellier, France, in 2012 found that more than a third of men were most attracted to images of women that had been digitally manipulated to resemble their own features.
There’s also an idea that after years together, couples start to look increasingly alike, a theory backed up by a 1987 University of Michigan study that found that partners who didn’t look alike at the start of a marriage experience a ‘degree of convergence positively correlated with couples’ ratings of marriage quality’.
However, this idea has been debunked by a more recent study by Stanford University in 2020, published in Scientific Reports.
Researchers compiled a database of photos of more than 500 couples taken in the first two years of their marriage and anywhere between 20 and 69 years later.
They asked volunteers to examine a photo of an individual and six others, including their spouse, and rank them by similarity, as well as performing the same task using facial recognition software.
However, they found no evidence of couples morphing into each other with age, and came to the conclusion that spouses’ faces tended to be similar to begin with.
