A team of researchers led by Michigan State University have debunked the myth that spouses grow similar over time. Instead, they claim, people choose their mates based on shared personality traits.
"Existing research shows that spouses are more similar than random people. This could reflect spouses' influence on each other over time, or this could be what attracted them to each other in the first place.
Our goal in conducting this study was to help resolve this debate," said Mikhila Humbad, lead investigator.
The researchers analyzed the data of 1,296 married couples, one of the largest such studies to date, said Humbad, MSU doctoral candidate in clinical psychology. The data came from the Minnesota Center for Twin and Family Research.
The researchers wanted to know if husbands and wives become more similar as the marriage progressed.
They examined a host of personality characteristics and found that, in most cases, the couples did not become more alike with more years of marriage.
The conclusion: Spousal similarity is better explained by selection than gradual convergence. The one exception to this pattern was aggression.
"It makes sense if you think about it. If one person is violent, the other person may respond in a similar fashion and thus become more aggressive over time," Humbad said.
The research could have implications for future spouses as well as their offspring.
"Marrying someone who's similar to you may increase the likelihood that you'll pass those traits on to your children," Humbad said.
The study appears in the latest issue of the journal Personality and Individual Differences.