"An attitude of gratitude" may sound like some cornball saying, but you'd better believe it's a whole lot more. In fact, being grateful for what you have can change your worldview and your life — and it just might be the key to a totally happy, healthy existence. Practicing an attitude of gratitude can be a total game-changer, and we can prove it because... science.

Several scientific studies have shown how having a mindset of thankfulness can benefit you many times over. "Gratitude not only makes people feel good in the present, but it also increases the likelihood that people will function optimally and feel good in the future," explain the authors — Robert Emmons and Michael McCullough — of a study on gratitude and well-being, published by the Journal of Personality and Social Psychology.

In the study, they had university students write down up to five things in their lives that they were grateful for once a week. In the results, the authors note, "Participants in the gratitude condition felt better about their lives as a whole, and were more optimistic regarding their expectations for the upcoming week. They reported fewer physical complaints and reported spending significantly more time exercising."

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As they suggest, being thankful can benefit your daily routine in numerous ways. Here are some of the things gratitude can do for you — all backed by science.

1. It activates you

Similar to the study above, other research from the journal Personality and Individual Differences also reports that grateful participants were more proactive about their health, more inclined to visit the doctor for regular checkups and tended to exercise more, according to Forbes magazine.

2. It helps you fight sickness

To piggyback on No. 1, being grateful not only makes you more aware of your health, but it also makes you healthier. Studies have noted grateful participants report fewer aches and pains and that they have better immune systems.

3. It relaxes you

Applied Psychology: Health and Well-Being published an article in 2011 that analyzed thankfulness and sleep. They found that people who wrote down things they were thankful for before bed fell asleep faster and stayed asleep longer. It's also been found to relieve aggression and stress.

4. It fosters relationships

Having a mentality of gratefulness has been linked to an overall better social life. "Gratitude appears to build friendships and other social bonds," Emmons and McCullough explain in their report. It can also make you a better friend, partner and team player. Let your friends and loved ones know how grateful you are for them by creating a personalized #ThankList on social and tagging everyone you're thankful for.

5. It makes you smarter

In a study out of the Journal of Happiness Studies on high schoolers, gratitude and materialism, the authors note, "We found that gratitude, controlling for materialism, uniquely predicts all outcomes considered: higher grade point average, life satisfaction, social integration, and absorption, as well as lower envy and depression."

6. It boosts your career

Happier Human explains that gratitude can make you a more effective manager, aid in networking, increase goal achievement, improve decision-making and boost your productivity. Being thankful has been known to improve your personality overall — a key component in the corporate world.

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7. It steadies your emotions

As noted earlier, gratitude studies show that it reduces feelings of aggression in participants, but it can also help you cope with traumatic events and has the tendency to make your memories happier.

8. It increases self-esteem

Forbes notes a study from the Journal of Applied Sport Psychology that found gratitude boosted self-esteem in athletes. Forbes also mentions other studies that show it reduces social comparisons and allows people to appreciate others' achievements as well as their own.

9. It makes you happier

The Huffington Post reports a study that showed gratitude made teens 17 percent happier and more hopeful. Many of the benefits of gratitude simply come from the fact that it makes you more optimistic — and optimism can make us happier and lengthen our life spans.

Originally published November 2015. Updated October 2017.