This is only one out of many studies showingthis. Writing elaborate (at least 300 words) gratitude letters is perhaps the easiest and nicest thing you can do to improve happiness. Extra points of happiness for someone else if you actually go there and read it out loud to them :)
That first article gives the results of a pilot study for the second linked paper so probably shouldn’t be considered additional evidence.
EDIT: Also, the results of the second study show that for the post writing period both the letter-writers and the control had the same response (within a half unit of standard deviation).
Writing down a letter of gratitude can substantially improve happiness for months
This is only one out of many studies showing this. Writing elaborate (at least 300 words) gratitude letters is perhaps the easiest and nicest thing you can do to improve happiness. Extra points of happiness for someone else if you actually go there and read it out loud to them :)
That first article gives the results of a pilot study for the second linked paper so probably shouldn’t be considered additional evidence.
EDIT: Also, the results of the second study show that for the post writing period both the letter-writers and the control had the same response (within a half unit of standard deviation).