One of the most robust findings in psychological science is our tendency to gravitate towards likeminded people. Psychologists call this homophily – literally “love of the same” – and it exist in nearly every culture. Despite where we grow up or how we grow up, familiarity is comfortable; we like people who reinforce rather than test our beliefs. This is true for a wide number of characteristics: sex, gender, religion, age, education and social class. As the idiom goes: Birds of a feather flock together.
Homophily is most apparent in marriage. Decades of research suggest that we are not only initially attracted to likeminded people but that familiarity is essential for healthy marriage. Consider the Chicago Sex Survey, one of the first comprehensive studies conducted on sex in the United States. One finding was that “the great majority of marriages exhibit homogamy on virtually all measured traits, ranging from age to education to ethnicity.” Likewise, a landmark study conducted by Miller McPherson found that personality traits are a good predictor of marital stability and happiness.
The paradox is why romantic fiction is obsessed with opposites. If data shows that we are drawn towards people like us – there is virtually no evidence that opposites attract – then why Romeo and Juliet, Harry and Sally, and WALL•E and EVE?





