It may not be the question for the ages, but it’s certainly a question that’s been pondered for ages: Do couples really begin to resemble one another the longer they’re together?
A pioneering study conducted in 1987 by University of Michigan psychologist Robert Zajonc suggested that based on factors such as diet, lifestyle, and compatibility, spouses did begin to look alike over the course of time. However, since the comparative data was gathered from a small pool of human volunteers, it was highly subjective.
With that in mind, some researchers at Stanford University decided to put the matter to a more clinical test. “It is something people believe in and we were curious about it,” Ph.D. student Pin Pin Tea-makorn told The Guardian. “Our initial thought was if people’s faces do converge over time, we could look at what types of features they converge on.”
Working with her Stanford colleague, Michal Kosinski, Tea-makorn put together a photographic database that tracked 517 couples checking for evidence of progressive facial assimilation. Initial pictures taken within two years of the pairs getting hitched were compared with images from 20 to 69 years down the road.
Long story short: Using data culled from both human volunteers as well as a follow-up from state-of-the-art facial recognition software, the findings didn’t turn up any evidence of the face-shifting phenomenon.
While some long-term couples did resemble one another more than randomly paired duos, it was likely due to the fact they started out with similar features to begin with.
The explanation for this anomaly is generally attributed to what’s known as “the mere exposure effect,” or the preference for choosing things with which we are already comfortable.
It’s the same reason people so often resemble their dogs, and vice-versa—at least according to an article in Psychology Today from Stanley Coren Ph.D.
So, if you and your partner start to look suspiciously similar as time goes by, chances are, you only have yourselves to blame.