Do opposites attract? What research on couples really shows

Mostly, birds of a feather

When researchers measure real couples, partners tend to be more similar than random pairs in age, education, background, political and religious attitudes, and values. Similarity in personality traits also exists, but it is surprisingly weak. In other words, people mostly pair up with someone who sees the world in a similar way, not necessarily someone who behaves the same way.

Why opposites seem to attract

There are a few reasons the opposites story feels true:

• Differences are memorable. You notice that your partner loves parties and you don't. You don't notice the dozens of ways you agree.
• Complementary roles are attractive early on. A quiet person may admire a partner's confidence; a spontaneous person may enjoy a partner who handles the bookings.
• We judge by behaviour, not values. Two people who act differently can still share the same priorities underneath.

What predicts a happy relationship

Here is the part that surprises most people. Large studies that compared thousands of couples found that how similar the partners' personalities were explained only a tiny share of how satisfied they felt. Each person's own traits mattered far more.

In particular, people who are higher in emotional stability, agreeableness and conscientiousness tend to report happier relationships, and their partners do too. Being with someone who is calm, warm and reliable helps, whether or not they are like you in other ways.

Where similarity does help

Some differences cause more day-to-day friction than others. In practice, couples most often clash over:

• Tidiness and planning, which relate to conscientiousness. One partner's “relaxed” is another's “chaos”.
• Social energy, which relates to extraversion. How many weekends should be spent with other people?
• Core values, such as security versus freedom. These shape big decisions about money, children and where to live.
• Daily rhythm. A morning person and a night owl may barely overlap. See chronotypes explained.

Differences in openness or extraversion can be enriching when both people respect them. Differences in values tend to need more conversation. The core values test is a good way to find these early.

How to make differences work

1. Name the difference without blame. “You recharge with people, I recharge alone” is a fact, not a flaw.
2. Find the strength in it. The planner keeps you on track; the improviser saves the day when plans fall apart.
3. Agree on defaults. For example, one social event per weekend, or the tidy person sets the system and both follow it.
4. Protect shared ground. Make time for the things you both enjoy so differences don't define the relationship.

See your own mix

The TraitMix Big Five test and Compare page show where you and someone else are alike and where you differ, trait by trait. Our compatibility score deliberately combines similarity with individual strengths, because that is what the research supports.

Frequently asked questions