Examining physical and behavioral traits of more than 5,000 married couples in the United States, researchers from Rice University and the University of Nebraska found spouses in the study appeared to instinctively select a partner with similar social and political views, a Rice release reported Tuesday.
"It turns out that people place more emphasis on finding a mate who is a kindred spirit with regard to politics, religion and social activity than they do on finding someone of like physique or personality," John Alford, a Rice professor of political science, said.
Using a scale of 0 to 1, where 1 meant perfectly matched, physical traits only score between 0.1 and 0.2 among spouse pairs, the researchers said.
Personality traits such as extroversion or impulsivity are also weak and fall within the 0 to 0.2 range.
By comparison, the study found, the score for political ideology is more than 0.6, higher than any of the other measured traits except frequency of church attendance, which was just over 0.7.
The research shows people's choices don't stop with where they live, with whom they socialize and where they work, but also figure in selecting spouses, Alford said.
"It suggests that, perhaps, if you're looking for a long-term romantic relationship, skip 'What's your sign?' and go straight to 'Obama or Palin?'" Alford said. "And if you get the wrong answer, just walk away."