Decades of research suggest that the old adage about birds of a feather is true — especially when it comes to education. People tend to marry people who have achieved similar levels of schooling. But the question is why? A new study of movie-star marriages — of all things — tries to bring some clarity to why this self-sorting occurs.
Social psychologists have not been able to account fully for certain factors that may explain why people pair up by education. It could be, for instance, that people simply end up marrying people they meet in college or grad school. Many others meet their future partners in the workplace, where people with similar backgrounds also end up together. Or it could be that education guarantees a few other desirable things like high income and other lifestyle traits, such as common hobbies, interests and abilities.
So Gustaf Bruze of the Aarhus School of Business and Social Sciences in Denmark decided to look at marriage and education trends in a group of people whose meeting and mating habits don’t follow the usual patterns: big-name movie stars.
Hollywood actors tend not to meet their partners in school, Bruze reasoned, and unlike the rest of the population, their formal education has no bearing on their job or their professional success, as measured by box-office draw, publicity or whether they’ve won an Oscar. (More on TIME.com: The Case for Letting Your Partner’s Eye Wander)
For the study, Bruze compiled a list of 140 married actor couples in which at least one of the spouses ranked high on the Ulmer Scale of Hollywood’s most “bankable” stars. He then assessed the marital status and years of formal education achieved for each person, using a variety of online sources, including Marquis Who’s Who and IMDb.com.
Bruze noticed a familiar pattern emerge: top actors end up marrying people with similar educational backgrounds, whether that spouse is another famous actor, or a similarly successful singer, model or musician, or a “regular” human. (More on TIME.com: The Secrets to Long Life: Worry, Work Hard and Marry Well)
Many of the famous married couples on Bruze’s list had achieved the exact same level of education: Tom Cruise and Katie Holmes (or TomKat, if you prefer) each have 12 years of schooling under their belts — which amounts to a high school diploma. Will Ferrell and his wife, Swedish actress Viveca Paulin, each have 16 years, as do Julianne Moore and her husband, Bart Freundlich. The Ivy-educated two-time Oscar-winner Meryl Streep (19 years) is married to sculptor Donald Gummer (also 19 years, including an M.F.A. from the Yale School of Art).
Of course, there are the exceptions. There were some couples with very different levels of education: Julia Roberts (12 years) and Danny Moder (16 years); Kevin Bacon (11 years) and Kyra Sedgwick (16 years); Demi Moore (10.5 years) and Ashton Kutcher (14 years). Aside from the standouts like Sedgwick (or Joya Tillem who went to school for 20 years, compared with her husband Jon Favreau’s 15), in most cases where educational achievements diverged widely, it was the woman who had less schooling than her husband.
“[A] larger fraction of male actors have obtained a college degree,” Bruze writes. “This difference between male and female actors is most likely due to a higher premium on youth for female actors, who respond to such incentives by interrupting their formal education at an earlier age.” (More on TIME.com: The 3-Year Itch: Are You Already Sick of Your Spouse?)
The findings don’t explain exactly why people seek out others with similar educational accomplishments, but they do suggest that it isn’t just about money or the result of circumstance. This adds to the discussion about such marital sorting, which is of concern to economists: when highly educated people disproportionately marry other highly educated people, it leads to more economic inequality in the society as a whole.
“The tendency of movie actors to sort on education in marriage, therefore, reveals important features of the marriage market that are useful for understanding marital sorting on education in the general population,” Bruze writes. “What it suggests is that a substantial degree of educational homogamy would remain in the economy even if, for example, the tendency of men and women to work with colleagues of a similar educational background were to disappear or if the role of educational institutions as a meeting place for future husbands and wives were to disappear.” (More on TIME.com: Can Your Mate’s Voice Be a Clue to Potential Cheating?)
No word yet on what kind of braniac James Franco might end up with.
The study is published in the Journal of Human Capital.