While there’s this old saying “opposites attract”, what our heart really wants is a person who resembles its owner—and that resemblance continues to increase the longer two people stay together.
In an experiment by University of Michigan psychologist Robert Zajonc, he concluded that the couples had grown to look more like each other over time. And, the happier the couple said they were, the more likely chances they were to have increased in their physical similarity.
He suggested that older couples looked more alike because people who are in close contact mimic each other’s facial expressions.
Other evidence showed that men and women may be initially attracted to partners with similar personalities. In 2006, scientists at the University of Liverpool concluded the couples that had been together the longest were judged to have more similar personalities.
It turns out we fall in love with people sporting DNA that is similar to our own in some ways.