No, it’s not just in your head — there could be a scientific reason why some couples look alike.
According to a recent report from the Boston University School of Public Health and the University of California, it could have something to do with genetics.
“Until recently, most people picked a spouse from within their local community, and that person often had the same ancestry. Over many generations, this affinity for similar mates has created a genetic structure in the population which has the potential to bias the results of genetic studies.” researchers said in a statement.
READ MORE: Ontario woman empowering, mentoring domestic abuse survivors
The report, which was published in PLOS Genetics on April 6, analyzed three generations of white people from the Framingham Heart Study (FHS). The FHS study, which started in 1948, originally followed 5,209 men and women between the ages of 30 and 62 in the town of Framingham, Mass.
Using genome-wide genotype data (or the study of genetics) to analyze 800 pairs of couples, the goal was to characterize their genetic ancestry, Yahoo reports.
“By examination of spouse-pairs, we observed that individuals of Northern/Western European, Southern European and Ashkenazi ancestry preferentially chose spouses of the same ancestry, however, the degree of endogamy decreased in each successive generation, especially between Northern/Western and Southern Europeans,” researchers wrote in the journal.
Opposites don’t always attract
One 2010 study from the University of Michigan found that overtime, more couples tended to look alike, according to Live Science, and it had nothing to do with genetics.
Psychologist Robert Zajonc analyzed photos of couples when they first got married and photos of them 25 years later.
As years passed, spouses looked more and more like each other, and Zajonc believed this was because they mimicked each other’s facial expressions. For example, if your partner had a good sense of humour, both of you will likely develop lines around your mouth.
Sometimes it’s in the face
But looking similar could also have to do with the selection process.
According to a 2010 report from Personality and Social Psychology Bulletin, people are attracted to others who look like their parents or themselves, Psychology Today reports.
In two separate studies, participants were shown pictures of strangers: one which was preceded by a photo of their own opposite-sex parent or stranger, and another which was a morphed photo of a stranger and a participant.
“When subjects were asked to rate the portrayed people for attractiveness, they usually picked the people who were an amalgamation of a stranger and themselves,” Psychology Today notes.
READ MORE: Should women be required by law to take their husband’s surname?
“It’s human nature to seek what’s familiar because what’s familiar is predictable,” says dating coach Chantal Heide based in Waterloo, Ont.
Heide, who has done her own research on the topic says she has also seen similar patterns to Zajonc’s work.
“When people see someone who resembles them there’s an automatic trust that takes place in the brain, and for someone seeking trust as one of their most important qualities in a partner, they’ll be subconsciously, naturally attracted to people who resemble them.”
Practical ways to find a life partner
But is this the best way to find someone to spend the rest of your life with?
“Practically speaking, looking for connectivity stemming from your existing social circles means you’ll find someone who’ll fit into your lifestyle more easily, because they’re already plugged into your social group,” Heide says. “Finding people who are like you means they’re more adapted to understanding you, your quirks, and hobbies.
READ MORE: Taking a break from your relationship? Here are the dos and don’ts
However, she says there is still some truth in opposites being attracted to one another.
“As nice as it is to have a buddy to do things with, someone who can fill in the gaps where you’re still figuring stuff out means you have a role model to help guide you towards becoming more accomplished in those areas.”