Gratitude Letter

Write to someone who helped you and never got told properly. Sending it is optional.

20 minutes to write, 5 to send · Once in a while, when someone comes to mind · Free

What it is

You write a letter to a specific person about a specific thing they did, and what it actually meant. Not a thank-you card — a letter that says the part you never said.

In the original research the strongest version involved delivering it in person and reading it aloud, which produced the largest short-term happiness gain of any single exercise tested. Kansha lets you email it, or keep it entirely to yourself.

Keeping it unsent is a legitimate choice. Plenty of the value is in the writing, and some of the people worth writing to cannot be reached.

How to do it

1. Pick one person and one thing. Specific beats comprehensive.
2. Describe what they did, in detail, including things they may not remember.
3. Say what it changed. This is the part people skip and the part that matters.
4. Decide whether to send it. Kansha can email it, or it can just sit in your account.

What you might get from it

• Produces one of the largest short-term wellbeing effects measured for a single exercise
• Tends to strengthen the relationship, when sent
• Works even unsent — the writing does most of the work

What the research says

Evidence: Strong. Seligman and colleagues tested five happiness interventions in a randomised, placebo-controlled trial. The gratitude visit produced the largest immediate effect of the set.

• Seligman, M. E. P., Steen, T. A., Park, N., & Peterson, C. (2005). American Psychologist. The gratitude visit produced large positive changes, though the effect faded over about a month. https://doi.org/10.1037/0003-066X.60.5.410

Where that runs out

The large effect was for the in-person visit, not for writing alone or emailing. It also faded — measurable at one month, largely gone by three. This is a lift, not a change of state.