9 signs you're in a strong relationship — even if it doesn't feel like it

In 2007, Stony Brook University researchers randomly dialed hundreds of adults and asked the nearly 300 who were married a series of questions about their relationships and how in love they felt.

Results showed that certain relationship characteristics were linked to stronger feelings of love. One especially interesting finding: The more often people reported thinking about their partner when they were apart, the more in love they felt.

The same study included a follow-up experiment with nearly 400 married New Yorkers, which found that difficulty concentrating on other things while you're thinking about your partner is also linked to strong feelings of love — especially for men.

Insider previously reported that one litmus test of a happy relationship is how enthusiastically each partner responds to the other's good news.

A Psychology Today blog post breaks down four ways a man could respond after his partner tells him about a promotion at work:

• An active-constructive response from him would be enthusiastic support: "That's great, honey! I knew you could do it, you've been working so hard."

• A passive-constructive response would be understated support — a warm smile and a simple "That's good news."

• An active-destructive response would be a statement that demeaned the event: "Does this mean you are going to be working even longer hours now? Are you sure you can handle it?"

• Finally, a passive-destructive response would virtually ignore the good news: "Oh, really? Well you won't believe what happened to me on the drive home today!"

Perhaps unsurprisingly, the response that's most closely linked to relationship satisfaction is the active-constructive response.

Over the past few decades, we've started placing increasing demands on our spouses. As Insider's Jessica Orwig reported, no longer do we expect them to be financial partners, protectors, and companions — now we also want them to provide personal fulfillment.

The psychologist who produced some of these findings, Eli Finkel, suggests that if you want to be happy in your marriage, it's best not to look to your partner for all your existential needs. Finkel recommends finding yourself in hobbies, friends, and work.

Neil Clark Warren, psychologist and founder of dating site eHarmony, previously told Insider that humor can be a "social lubricant" in a romantic relationship.

Business Insider's Erin Brodwin has reported that having a "private language" with your partner — like nicknames and jokes that no one else would get — can help facilitate bonding and often predicts relationship satisfaction.

In one poll, 56% of married Americans said sharing household chores is "very important" to a successful marriage — that's more than the percentage who said having adequate income was very important. Chore-sharing seems to be especially meaningful to younger couples, with 67 percent of 18- to 29-year-old married adults calling it "very important" to a successful marriage.

But while men are doing more housework than they were in years past, research has found that women still pick up most of the slack.

In research led by relationship expert Art Aron in the Journal of Social and Personal Relationships, researchers looked at the relationship quality of more than 50 middle-aged married couples and assigned them to one of three groups.

One group picked new and exciting activities to do together for 90 minutes a week — like going to a play or dancing. Another group spent 90 minutes a week doing pleasant but routine activities together — like going to a movie. The last group wasn't asked to change anything.

After 10 weeks, the researchers reassessed the couples' relationship quality and found that those who had tried new and exciting things were the most satisfied.

As The New York Times reported in 2008:

"Dr. Aron cautions that novelty alone is probably not enough to save a marriage in crisis. But for couples who have a reasonably good but slightly dull relationship, novelty may help reignite old sparks."

Researchers from the University of Illinois at Urbana-Champaign and the Pennsylvania State University at Harrisburg looked at nearly 400 dating couples. They used their feedback about their relationships to identify four patterns of commitment: dramatic, conflict-ridden, socially involved, and partner-focused.

As psychologist and relationships expert Gary Lewandowski explains, dramatic couples showed a lot of fluctuation in their commitment to their partners over time.

Partner-focused couples saw their partners positively and mostly experienced fluctuations in commitment when they couldn't spend as much time together.

Socially involved couples usually experienced fluctuations when their friends and family changed what they thought of the relationship.

Finally, conflict-ridden couples fought often and had a lot of mini-fluctuations in their level of commitment.

As it turns out, partner-focused couples were most likely to get more serious in their relationship, and dramatic couples were most likely to break up.

Psychologist and relationship expert John Gottman previously told Insider that the No. 1 shared trait among successful relationships is being able to repair the bond after a fight.

It's not about not having conflict at all — instead, it's about the way you approach it. Gottman told Business Insider:

"The thing that all really good marriages and love relationships have in common is that they communicate to their partner a model that when you're upset, I listen.

"The world stops, and I listen. And we repair things. We don't let things go. We don't leave one another in pain. We talk about it, and we repair."

A little bit of gratitude goes a long way.

One 2010 study supported by the National Institute of Mental Health found that couples that expressed more gratitude were more satisfied in their relationships than those who expressed less gratitude. Moreover, couples where both partners felt appreciated by the other were less likely to break up nine months later than those who didn't feel as much appreciation, according to a separate 2012 study published in the Journal of Personality and Social Psychology. 

"Even small expressions of gratitude and appreciation can help improve relationship satisfaction," Andrea Bonior, clinical psychologist and author of "Detox Your Thoughts," wrote in a Psychology Today post. 

Ivan DeLuce contributed to an earlier version of this article that was originally published in 2017.