What makes us want to be friends with someone? What makes for a good, satisfying romantic relationship?
Some people would say that opposites attract. But frankly, decades of empirical research point in the other direction: Compatibility is based on having things in common. While there seems to be a role for complementarity — i.e., small difference that can enrich our lives by knowing that person, when it comes to big things like core values, the more you have in common with someone else, the more you like them. And the better you’ll get along with them.
This is well demonstrated in psychological research, which has shown that when speaking of interpersonal attraction that the rule of similarity is king. We like those most who share much in common with us. Or to put it another way, the proverb “birds of a feather flock together” is far more valid than “opposites attract.”
Opposites may attract ATTENTION, and people can become physically addicted to the adrenaline rush that can accompany constant conflict, but when it comes to true compatibility, you’re best off being with someone who is like you. Not identical, but differences should be complementary rather than adversarial in order to help balance the pairing.
Anyway, the tendency to like people we have a lot in common with is known as the attraction-similarity hypothesis. And it’s been around an awfully long time — and has stood up under intense scrutiny.
A Sampling of the Available Research
There are a lot of studies in this area. I’ll list a very small sampling (including one older classic study) if you want to check them out:
- Attraction as a linear function of proportion of positive reinforcements (1965)
- The similarity hypothesis: A test of the moderating role of social comparison orientation (2001)
- Relationship satisfaction as a predictor of similarity ratings: A test of the attraction-similarity hypothesis (2005)
- Similarity in relationships as niche construction: Choice, stability, and influence within dyads in a free choice environment (2017)
- Birds of a Feather Do Flock Together: Behavior-Based Personality-Assessment Method Reveals Personality Similarity Among Couples and Friends (2017)
This post is part of an ongoing Poly Land feature called Psyched for the Weekend, in which I geek out with brief takes about some of my favorite psychological studies and concepts. For the entire series, please see this link.