Do opposites attract? Pop culture thinks so. Movies like Pretty Woman and The Notebook suggest that couples with virtually nothing in common are destined for each other. Psychological studies paint a different picture. When people have a choice, they seek people who are just like them. Psychologists call this the similarity-attraction effect (SAE) and it shows itself across many cultures.
The SAE is especially pronounced between romantic couples. For example, in the early 1990s the Chicago Sex Survey collected data to find out where and how Americans met their partners. It found that “people search for – or, in any case, find – partners they resemble and partners who are of comparable ‘quality’… the great majority of marriages exhibit homogamy on virtually all measured traits, ranging from age to education to ethnicity.”
The same is true of our friends. This is what a recent paper by Angela Bahns, Kate Pickett and Christian Crandall at Wellesley College and the University of Kansas demonstrates. The researchers were interested in how the social diversity of a college influenced social relationships: Did more socially diverse schools lead to more diverse relationships?
To find out they compared the relationships of students at a large state university (University of Kansas) with four small colleges in Kansas. They accomplished this by asking students about their demographic information, behaviors and beliefs (opinions on birth control and under age drinking for instance). They found that the “greater human diversity within an environmental leads to less personal diversity.” The students at the University of Kansas, in other words, tended to create more homogeneous social groups compared to their peers at smaller schools. This means, ironically, that the more opportunities there are to pursue diverse relationships the more we tend to gravitate towards likeminded people.
This can be a problem. Several studies conducted over the last decade illustrate the importance of intellectual diversity. An analysis of Stanford Business School graduates found that “entrepreneurs with more ‘entropic’ and ‘diverse’ social networks scored three times higher on a metric of innovation, suggesting that the ability to access ‘non-redundant information from peers’ is a crucial source of new ideas.” Similarly, Brian Uzzi and Jarrett Spiro found that the most successful Broadway musicals combined new blood with industry veterans; too much familiarity or novelty within the staff was a killer of quality content.
In the context of marriage the SAE is a good thing. Marriages usually succeed when two likeminded people are involved; the similarity of personality traits is a good predictor of marital stability and happiness. In fact, it’s especially unlikely for people with dissimilar personalities to be attracted to each other. It’s not merely that opposites don’t attract: They often repel.
If opposites don’t attract romantically, why do we have such a propensity to believe that they do? For one thing, we humans love romantic stories. From Romeo and Juliet to EVE and Wall-E to Katniss and Peeta, we can’t help but fantasize about pairs of star-crossed lovers. Unfortunately, because stories sacrifice reality for more passionate and heart wrenching plots our perception of romantic relationships is heavily distorted. Not everything has a happy ending.
In brief, then, romantic relationships thrive on similarity. The opposite is true for your social and professional circles: when it comes to generating ideas, being creative or entrepreneurial, intellectually diverse social circles are key.