Gratitude practices help - modestly, and unevenly across countries
What they found
Gratitude exercises - a gratitude journal, a thank-you letter - raised well-being a little, most clearly positive mood. The size differed by country.
How they know
A registered meta-analysis: 145 papers, 24,804 people, 28 countries. The effect was clear in the United States, Germany, Hong Kong and others, but not confirmed in France, India, Japan, the Netherlands or the United Kingdom.
What it means for you
Expect a modest, low-cost lift, not a cure. Thanking someone properly after you meet is in the same spirit, though untested.
The limits
Small, self-rated, half the results American. Most unconfirmed countries had near-average estimates with wide margins (Britain's sat above America's), so the gaps may be partly noise; no culture measure explained them. Against other positive exercises, rarely tested, gratitude did no better. English-only search.
This is a short takeaway in our own words, not a reproduction of the study. For the method, the sample and the caveats, read the original.
