Siblings or dating? It’s an amusing game we’ve all found ourselves playing at one point or another when spotting a couple who share an uncanny likeness. Hell, there’s even an Instagram account dedicated to the game, with a mass following of almost 460k. But what is this phenomenon all about?
Researchers have long questioned whether there was any scientific explanation for couples who share a similar, and in some cases, near-identical appearance.
A 1987 study out of the University of Michigan previously set out to discover whether couples in long-term relationships began to take on each other’s features. Through their research, the team was able to conclude that married couples of 25 years did indeed share similar facial expressions and age lines as a result of their shared cohabitation.
They theorised that by conversing regularly, couples would mimic their partner’s facial expressions somewhat unconsciously, which over a long period, would permanently change the shape of their faces. They called it facial homogony.
“Two people who live with each other for a longer period of time, by virtue of repeated empathic mimicry, would grow physically similar in their facial features,” the researchers said. “Kin resemblance, therefore, may not be simply a matter of common genes but also a matter of prolonged social contact.”
This particular study was conducted on a small group of only 12 couples, so while the research held merit for a while, it wasn’t long before others began to interrogate the process and thus question the validity of the conclusions.
In newly published findings from a study out of Stanford University, researchers debunked the long-held theory once and for all via a much larger-scale study of digital images from 517 couples over a 20-69-year marriage period.
Using both human judgement and a facial recognition algorithm, the scientists worked to disprove the belief that couples’ faces converge over the course of a marriage.
“A closer look at the literature reveals that while the convergence in physical appearance hypothesis is one of the tenets of current psychological science and has been widely disseminated through textbooks, books, and landmark papers, it has virtually no empirical support.”
So there goes that theory. But then what is the real explanation for couples who look like siblings? Well, according to scientists and psychologists, it all comes down to attraction. Multiple studies would indicate, quite frankly, that we’re vain and find attraction in people who share our own physical characteristics.
“What is familiar to us tends to be what we like and are drawn to,” Justin Lehmiller, a US social psychologist and research fellow at the Kinsey Institute, told Time.
“You’re familiar with your own appearance, so seeing other people who share those similar sorts of traits might lead to more liking for that reason.”