As a personality psychologist, I am occasionally approached for advice on how to build a new app or platform for bringing people together.
Once, it was students who wanted to create an app that would help people find friends on campus. Not necessarily romantic partners, but simply people you would like to go out with in the evening and have a good time. Their working assumption was that people should be similar in their personality traits to have fun and enjoy themselves.
I instantly thought about myself and one of my old friends, who used to be my preferred company when going out in the evening. Sure, we shared certain traits, such as empathy and a sense of humor, but unlike me, they were super extraverted and chatty. With my friend, I could not only tag along in a busy pub, but some of their charm and social confidence seemed to rub off on me as well, and I became a lot more sociable and outgoing too.
So what I tried to explain when talking to those students was that it is more than pure similarity in personality traits that makes people like each other and want to spend time together. As with friends, the same applies to romantic relationships. In fact, it is a well-replicated research finding that greater similarity in couples’ personality traits is not associated with higher relationship satisfaction (Leikas et al., 2018). But is there any similarity in couples’ personality traits to start with?
Do We Look for People Like Us?
Despite many outcries that dating apps are dying, about one-third of over 10,000 U.S. couples who got married in 2025 had met their partners through online dating sites or apps (The Knot Real Weddings Study 2026). What dating apps usually do is use complicated algorithms to match users by their interests, hobbies, attitudes, socio-economic status, and so on.
For quite a few dating apps, though, personality is central to matching. These apps offer their users a personality test and compatibility percentages with potential partners, some including only similarities but others include differences too. While it is, of course, impossible to know exactly how these personality-matching algorithms work, does matching people based on their personality traits make sense at all?
A 2023 study showed that in a simulated dating app scenario, people with higher levels of agreeableness and openness to experience also valued these traits in the dating profiles of the individuals they were interested in matching with (De La Mare & Lee, 2023). In other words, kind and empathetic individuals were looking to match with people with the same qualities, and people open to new experiences were looking for those who shared their level of curiosity and taste for variety. And vice versa.
The study also found that people preferred profiles with similar levels of extraversion, which had not been confirmed by previous studies. According to the authors, the COVID-19 pandemic may have played a role here, as it imposed strict restrictions on people’s social activity, making it desirable to find someone with a similar level of preferred social activity.
Do We End Up With People Like Us?
If we seem to seek out people with certain similar personality traits, does it also translate into how similar actual couples are in their personality traits?
A recent study examined personality similarities among 451 Dutch married couples who, on average, had been together for nearly 30 years (Lee et al., 2026). Similar to several previous studies, they found that couples showed moderate similarity in two of the aforementioned personality traits: honesty-humility (closely related to agreeableness) and openness to experience. Couples were similar to each other in both their actual and perceived ratings, the latter indicating how they perceived each other’s personality traits.
Looking at the facet level of honesty-humility, people in long-term relationships seem to share an understanding of basic moral values, such as whether it is acceptable to cheat or take advantage of other people or society at large, as well as what kind of life they aspire to: Is it important to have a lot of wealth or status, or live a quieter, more modest life?
Personality Essential Reads
As regards openness to experience, people in long-term relationships share their level of appreciation of nature and various forms of art, as well as curiosity about life in general and how the world works. This could be seen in shared interests in reading books, appreciating an evening out at a theatre, traveling, or simply having enough to talk about.
Overall, this shows that the same traits that people are trying to match when looking for a potential partner also characterize long-term couples who have managed to stay together for decades.
“Put Your Records On, Tell Me Your Favorite Song”
The personality similarity between partners is, however, relatively small, especially when compared to attitudes, values, and many other individual characteristics. A large-scale meta-analysis showed that, except for openness, couples had positive but marginal similarity in the remaining four Big Five traits (Horwitz et al., 2023). Out of 22 traits, the similarity in extraversion, neuroticism, and agreeableness was the smallest. Couples were, however, strikingly similar in political attitudes, religiosity, educational attainment, and even whether they smoke or not.
Another recent study by Vigl and colleagues (2026) confirmed that among young adult couples, with a relationship length between 3.5 and 6.5 years, personality similarities between partners were negligible. Couples were, however, fairly similar in their music taste and, to some extent, also in their values.
Why is compatibility in terms of shared music preferences more important than shared personality traits? As the authors argue, several different explanations might be at play. First, shared musical taste may offer opportunities for shared social activities, such as going to concerts and festivals or even making music together.
Second, our music preferences and taste—our music identity—form an important part of our self-concept, how we relate to the world and see ourselves (MacDonald & Saarikallio, 2022). Musical identity typically develops during the years of adolescence and often reflects our ethnic and cultural background, as well as social class. Thus, music preference is not just about music, but reflects wider individual as well as cultural characteristics of a person.
Why Are Couples Similar?
One possibility is that people with certain characteristics, both psychological and physical, are attracted to each other and form a relationship. For instance, couples are also similar in their physical height (Horwitz et al., 2023) and in how similar spouses’ faces are at the beginning of marriage (Tea-Makorn & Kosinski, 2020). This is what is called assortative mating in psychology. However, it is also possible that people become more similar across the lifespan and through shared life experiences (not in their faces, though, contrary to some popular myths).
A way to tease these explanations apart is to investigate how similar partners are in the genetic factors associated with personality traits. This is exactly what was done in a major recent study on the genetics of personality traits that was published in Nature earlier this month—a massive collaborative effort involving many research groups and biobanks around the world (Schwaba et al. 2026).
The study shows that assortative mating for the Big Five personality traits was very small. The genetic similarity between spouses in terms of the Big Five was minimal, and nearly nothing compared with the fairly substantial genetic similarity between spouses in terms of educational attainment. In other words, spouses show much greater similarity in the genetic factors associated with educational attainment than in those associated with the Big Five personality traits.
So, Do We Fall for People Like Us After All?
Taken together, we do fall for people like us, at least to some extent. We seem to be attracted to people who match certain personality traits, such as agreeableness (closely related to honesty-humility) and openness. These are the same two personality traits that long-term couples most often share—a general outlook on life and people in terms of honesty and status, as well as an appreciation of intellectual activities and art, open-mindedness, and a tendency to keep learning and trying out new things. But perhaps more importantly, we seem to seek out people who are similar to us in terms of their political attitudes, educational attainment, or even music preferences. Broadly speaking, these characteristics are also part of our personality or who we are.
So, if politics seems too contentious to discuss on the first date, asking about your potential partner’s favorite bands and books may be a good start. Later, their aspirations for life, especially in terms of money and status, and their general take on life, education, and moral views may also be worth discussing. After all, these seem to be the characteristics that people in long-term relationships tend to share, and that may contribute to relationship duration and satisfaction.
