This 1 powerful phrase is the science-backed secret to a happy relationship (and most of us rarely use it)

Source: NBC

When it comes to building successful relationships, going the extra mile to express your gratitude is important.

Even now, in this very moment, we're grateful that you're taking the time to read this article. Of the millions of other articles out there, you chose to spend your time here. And we're not just grateful for you, we're also grateful for the parents and teachers who taught you how to read and influenced your desire to learn.

When recognizing people for their contributions and efforts — whether in your romantic or professional life — it's common instinct to say "thank you" (or just "thanks"). We also use it as a way to end a conversation or to say goodbye, but because we're used to hearing them so many times, the phrase can lose meaning and sincerity.

In the book "Thanks a Thousand: a Gratitude Journey," author A.J. Jacobs describes his journey traveling the world and thanking everyone he encounters, including the ones he would typically take for granted, such as the people behind his morning cup of coffee — from the barista to the farmers who harvested the beans.

The experience taught Jacobs how gratitude — and the way we show it — can make us all more generous, connected, and most important of all, happier in our relationships. But it isn't as simple as just saying "thank you."

"The phrase 'thank you' is often seen as robotic — a mere verbal reflect," Jacobs writes. "If you switch it up with other gratitude phrases, maybe it will jolt people awake, cause them to take notice."

The more effective alternative?

"I'm grateful."

When you change things up, people will pay more attention to your expression of gratitude. You might even recognize an increase in performance and positive emotions. In fact, a study from the American Psychological Association found that saying "I'm grateful" can help people "savor positive experiences," "cope with stressful circumstances" and "strengthen relationships."

For the study, researchers Adam Grant and Francesca Gino designed an experiment in which the director of a fundraising campaign oversaw two groups of fundraisers. Midway into their campaigns, the first group didn't hear an expression of gratitude, whereas the second group was told: "I'm very grateful for your hard work." The second group ended up making 50 percent more calls to potential donors than the average fundraiser per week. In short, gratitude helped motivate the fundraisers.

So the next time someone opens the door for you, say "I'm grateful for your kind gesture." When your colleague wishes you a happy birthday, respond with "I'm grateful for your well wishes." It doesn't even have to be a response to an immediate reaction — when you come home from work today, tell your significant other or call your parents and tell them, "I'm grateful for all your support." You could also start signing off your emails with "gratefully" or "with gratitude."

All of these expressions are much more emotive than a short "thanks." Even better, they'll measurably improve your overall satisfaction and happiness in your relationships.

Deepak Chopra is the co-author of "The Healing Self,"founder of The Chopra Foundation and co-founder of Jiyo and The Chopra Center for Wellbeing. Kabir Sehgal is a New York Times best-selling author. He is a former vice president at JPMorgan Chase, multi-Grammy Award winner and U.S. Navy veteran. Chopra and Sehgal are co-creators of Home: Where Everyone Is Welcome, inspired by American immigrants.

Don't miss: Deepak Chopra: Taking these 3 steps will make people like and trust you at work

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3 simple things you can do right now to win at work
3 simple things you can do right now to win at work