One of your most powerful tools — to improve health, bolster relationships and just feel better — is your smile. It's that simple.

• Why it matters: Americans tend to smile more and wider than folks in other countries, research shows. Those megawatt grins are actually good for our mental and physical health.

Zoom in: The science-backed benefits of smiling include stress relief, pain relief and strengthened relationships.

1. Smile the pain away: Research has shown that smiling during running can make you more efficient and make the run feel more manageable. Our smiles send cues to our brains that we're OK.

• One study found that smiling during a shot can lessen the perceived pain of the needle.

2. De-stress: When you smile in a tense situation, your body has a real, physical response, researchers at the University of Kansas found. Your heart rate slows down, and your stress starts to melt away — even if you're not actually feeling smiley. Basically, fake it till you make it.

3. Look your best: It's a fact — we find people more attractive when they smile.

4. Make a friend: One of the reasons Americans smile so much is our nation's diversity. "It turns out that countries with lots of immigration have historically relied more on nonverbal communication," Olga Khazan writes in The Atlantic. "Thus, people there might smile more."

• Smiling at work can make you appear more trustworthy and deepen bonds with coworkers, according to the Wharton School of Business.

The bottom line: Many of us took grins for granted until pandemic-era masking made smiles invisible overnight.

• Try it the next time you're in a traffic jam — now that those are back.

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Americans smile often, but we don't even crack the list of top 10 happiest countries, according to Gallup's 2022 Global Emotions report.

• The 3 most positive nations are Panama, Indonesia and Paraguay.

The bottom 3 are Afghanistan, Lebanon and Turkey.