The age-old notion that opposites attract has permeated rom-coms and romance novels for decades. But when it comes to real life, research tells a different story: people are actually drawn to those who resemble them. Numerous studies spanning several decades have consistently shown that shared traits are a strong predictor of long-term attraction and successful relationships.
Erica Slotter, a psychologist at Villanova University, explains that while we might occasionally see couples who seemingly have little in common, this is more of an exception. “Similarity is still a robust predictor of attraction,” she says. This phenomenon holds true across all stages of relationship development, from initial attraction to long-term commitment.
Researchers have delved into people’s stated preferences, exploring what attributes they claim to seek in a partner. Slotter notes, “Most of the time, people say they want people who are like them.” This desire for similarity extends to various aspects of life, including socioeconomic status, religious beliefs, political orientation, and hobbies.
Examining data from long-term relationships further reinforces the power of similarity. Tanya Horwitz, a researcher at the University of Colorado Boulder, conducted a study analyzing past literature and large-scale demographic datasets. The findings, published in the journal Nature Human Behaviour in 2023, revealed that up to 89% of traits between partners were positively correlated. This means that if one partner engages in a certain activity, like exercising regularly, their partner is likely to do the same. This correlation extends to political views, health habits, substance use, and more. “It was surprising just how uncommon it is to see a trend where people are less similar,” Horwitz remarked.
Does this mean we’re destined for a relationship with someone who’s our exact twin? Not necessarily. While shared traits are vital, there’s room for differences, especially in areas like social dominance. Slotter explains that if both partners are highly dominant, they might clash frequently. Conversely, two submissive individuals might struggle to address relationship problems effectively. Pairs with contrasting levels of social dominance tend to experience greater satisfaction, as they offer a balance of assertiveness and cooperation.
Beyond shared values and interests, chemistry also plays a role. Speed dating studies have shown that what we say we want in a partner doesn’t always align with who we’re physically or emotionally drawn to. The exact workings of this phenomenon remain somewhat mysterious. Slotter suggests that while we consciously look for similarity in initial interactions, we also unconsciously assess for a more holistic sense of compatibility. This increased holistic similarity is linked to stronger romantic chemistry.
While couples may start with differences, they can become more similar over time through a process known as convergence. Horwitz explains that spending time together naturally influences habits and lifestyle choices. This shared experience can enhance attraction and strengthen the bond as the relationship progresses.
Ultimately, the perception of similarity can be just as impactful as objective shared traits. A 2000 study in the Journal of Experimental Social Psychology found that whether strangers or friends perceived a couple as similar didn’t significantly affect relationship satisfaction. Instead, it was the couple’s own belief in their shared qualities that mattered most.
Slotter emphasizes the importance of subjective judgment: “If you feel like this person is similar to you, go for it. Because … that seems to matter the most.” So, while it’s true that opposites attract in fiction, in real life, shared traits and a genuine feeling of connection are the cornerstones of a lasting relationship.
