5 Factors Linked to Successful Relationships, According to Science

Updated: Dec. 31, 2020

Falling in love is the easy part. Here's some relationship advice for how to make it last—according to science.

Forget all the relationship advice you learned from rom-coms about finding Mr. or Ms. Right. When it comes to having a successful relationship, the person you choose to date may not be as important as the relationship you choose to make, according to an August study published in PNAS.

There are thousands of studies looking at relationships but this one is unique, both in how it was conducted and what they discovered. Over 85 researchers, led by Samantha Joel, PhD, of Western University in London, Canada, used machine learning to comb through data from 43 separate studies of over 11,000 couples from Canada, the United States, the Netherlands, New Zealand, Israel, and Switzerland.

Unlike human beings, the computer network was able to look at millions of data points and find which factors truly predicted a successful relationship. And what they found might surprise you.

Which factors do not predict a successful relationship?

When you think of all the factors that make for a happy romantic relationship, you likely have a list of things that matter—and those that don’t.  But many of these “obvious” factors—such as education, income, stress levels, anxiety, relationship beliefs, extraversion/introversion, ethnicity, self-control, and life values—turned out to have little to do with a successful relationship, according to the study. That’s right, something as core as life values turned out to have a very weak connection with being able to form and sustain a good relationship.

Okay, so perhaps those things don’t matter on their own but maybe the key is to find someone who matches with you on those characteristics of a healthy relationship? Or is it opposites attract? Again, the answer isn’t the standard romantic trope. The researchers found no evidence in the data for “birds of a feather flock together” or “opposites attract.” (These quotes capture what it’s like to fall in love.)

The most important factors for a long, happy relationship

So, what actually did make the list and why? The study looked at what factors were correlated with happy relationships and taken together they accounted for nearly half of whether or not a relationship was successful. (Success was defined by how a person rated their own happiness in the relationship). A person’s thoughts about the relationship—including how satisfied and committed they thought their partners were and how appreciative they felt towards their partner—was responsible for about 45 percent of their current satisfaction with the relationship.

Here, we break down the top five factors linked to relationship satisfaction with the help of Gary Brown, a licensed psychotherapist, in Los Angeles, who was not involved in the study.

Trust: Believing your partner is committed to you

“This is about being assured that your partner is in it with you for the long haul,” says Brown, who’s also a couples therapist with over 30 years experience and named Best Marriage Counselor by Los Angeles Awards in 2015. Trust in a relationship was likely ranked at the top of the list because there’s no point in moving forward with anything else until you’ve established that you’re both committed to making it work. You can’t improve a relationship if you’re unsure your partner even wants to be in the relationship, he explains.

What to do: “Don’t assume that your partner knows how you feel about them, make an intentional effort to tell and show them that you love them and that you value your relationship as a couple,” he says. Here are some expert tips on how to build trust in a relationship.

young couple smiling and embracing each otherPeter Amend/Getty ImagesGratitude: Feeling appreciated by your partner

“People have a basic need to feel valued and like they have worth, and it’s normal to seek this from your partner,” Brown says. Too many couples get caught in the trap of feeling like they “shouldn’t have to” show gratitude to their partner but there’s no such thing as too much appreciation, especially when it comes to those closest to you, he says.

What to do: Don’t take your partner for granted. Learn your partner’s love language and then find ways to show them the appreciation that will feel meaningful to them, he says. There are five love languages or ways to express and experience love: words of affirmation, quality time, gifts, acts of service, and physical touch.

For instance, someone who shows love through gifts may feel appreciated with a “just because” bouquet of flowers. Start with these tiny ways to make your partner feel loved.

Romance: Having a satisfying sex life

Why this is an important factor in a relationship isn’t a mystery and yet so many people don’t make good, quality sex a priority, Brown says. “Sex plays a multi-layered role in a relationship, expressing lust, bonding, emotional connection, closeness, and vulnerability,” he explains.

What to do: A satisfying sex life is all about quality over quantity, he says. So one great session a week might be better than daily quickies—but of course, it depends on what the partners are looking for in their sex life. “Forget what you’ve heard ‘normal’ is and work with your partner to create your own ‘normal,'” he says. “Then make it a priority in your life.” To prioritize physical intimacy, couples might want to try scheduling sex.

Selflessness: Seeing your partner is happy

The best relationships are the ones where each person cares about the other’s happiness more than their own, Brown says. This doesn’t mean becoming a martyr and making your partner happy at the expense of your own needs but rather having an unselfish attitude in the relationship.

What to do: “Ask yourself every day, ‘What is something I can do today to make my partner’s life easier today?’ and then do it,” he says. “Keep the conversation going and check in with them regularly to see if they really are happy and give them permission to be honest and authentic if they aren’t.” Find out if having a relationship coach could help you in these situations.

Engaged: Being willing to navigate conflict

Most people fight once in a while so successful relationships aren’t about avoiding conflict but about developing healthy ways to resolve it, Brown says. “The goal of conflict resolution should always be to gain understanding, not to ‘win’,” he explains. Fighting for the sake of fighting or to prove you’re right or to humiliate your partner is toxic and will poison your relationship faster than almost anything else, he adds.

What to do: Each couple needs to find a healthy style of conflict resolution that works best for them. If you are unsure how to “fight fair,” try reading books on the topic, talking to people whose relationship you admire, or schedule a few sessions with a relationship counselor, he says.

Being the right person

Similarly, being the right person matters far more than finding the right person. Why? “Ultimately you are the only one you can control,” Brown says. But with so many different things to focus on, which personality traits are the most crucial to building a great relationship? The study has answers for that too.

The researchers found that out of all the individual characteristics studied, the ones that had the biggest effect on relationships were life satisfaction, a personality trait known as negative affect (corrosive negativity), depression, and having a healthy attachment to your partner. (There are thought to be three major attachment styles in relationships, and people with anxious and avoidant styles are thought to have less stable relationships than people with a secure attachment style.)

Taken together, these factors accounted for about 20 percent of relationship success. Notice none of these involve losing 20 pounds or earning six figures. Working on these important aspects of yourself creates the ideal conditions for a relationship to flourish and grow, he explains.

Why this matters

Unhappy relationships can have a huge impact on your health and happiness, and are linked to poor physical health, higher blood pressure, a weaker immune system, a higher risk of early mortality, and mental health problems, the researchers noted. Plus, bad relationships tend to bleed into all other aspects of life, hurting your career, friends, and children. On the other hand, happy relationships can lead to improved outcomes in almost every area of your life.

“We are hardwired for social connection and pair bonding, as human beings, we need it,” Brown says. The findings of this study are a really hopeful message because it shows you do have a lot of control over your relationship satisfaction, he says. “This idea of kismet or serendipity, that when you meet your ‘soulmate,’ you’ll just know, and things will magically work out, is garbage,” he says. “The most dangerous relationship myth is that a good relationship shouldn’t take work, that it should just happen.”

“Any idiot can fall in love, that’s the easy part,” he says. “Building, sustaining, and growing that love—that takes intention and hard work. The real message here is that having a shared vision that you’re willing to work towards as a team can overcome nearly any relationship or personal obstacles.”