Micro-Acts of Joy: Run the 7-Day Big Joy Protocol on Your Data

In June 2025 researchers at UC San Francisco published the results of the Big Joy Project, a free online program in which participants did one small, joyful act a day for a week. After analyzing 17,598 people from 169 countries, the team reported meaningful gains in emotional wellbeing (effect size d = 0.48), positive emotion (0.45), lower stress (−0.35), and modestly better sleep (0.15), with a clear dose-response: the more days people completed, the bigger the gains. Younger and socially disadvantaged participants benefited most.

That’s a large, cheap, fast effect from something that takes minutes. It’s also a study with no control group and self-reported outcomes, which the authors acknowledge, so the right response is neither “this is settled” nor “this is fluff.” It’s “run it on yourself and see.” (Disclosure: we build MoodKit, which runs exactly the kind of one-week experiment this calls for. Not medical advice.)

The acts

The paper describes seven daily micro-acts adapted from validated positive-psychology exercises, each designed to take under ten minutes. The ones the researchers highlight in their public summaries: ask someone to share a fun, inspiring, or proud moment; write a gratitude list; do a kind act to brighten someone’s day. The rest come from the same families of exercise, and here is a seven-day set built from them that we’ve used ourselves. It isn’t the official list, and it doesn’t need to be; the point is one act, once a day.

Day	Act	Family
1	Ask a friend to tell you about a moment they’re proud of	Connection
2	Write three specific things you’re grateful for today	Gratitude
3	Do one small kindness for a stranger or colleague	Kindness
4	Watch or step into something vast: a skyline, a storm, a piece of music	Awe
5	Take a five-minute walk and count the things you’d normally miss	Savoring
6	Congratulate someone on good news, properly, in full sentences	Celebrating others
7	Take one stressful thing from this week and write what it taught you	Reframing

Run it as a one-week experiment

The study measured before and after. You can do better, because you can measure during, and you can compare against a baseline the study didn’t have for you.

1. Baseline first. Log your mood for a week or two before you start, fifteen seconds a check-in. Without this, “I felt better” is unfalsifiable.
2. Make the act a tag. Add a custom activity called “micro-act” and tag it on the check-in you make after each day’s act.
3. Start the experiment. MoodKit’s try-a-habit experiment takes a habit, watches it for seven days, and compares the week against your baseline. At the end you get a verdict, computed from your own entries, and it’s willing to say “no measurable effect.”

The study’s effect sizes are a useful yardstick. A d of 0.48 on wellbeing is a noticeable shift, not a transformation; on a 1-to-5 mood scale, expect something like a few tenths of a point if you match the average. If your week shows more, good. If it shows nothing, the second week below is where it gets interesting.

Which act carried the week

The published study can’t tell you which of the seven acts did the work; participants did all seven, and the analysis is of the bundle. You’re not stuck with that.

Run a second week with each act as its own tag (“gratitude,” “kindness,” “awe,” and so on). After a couple of weeks, MoodKit’s Impact Leaderboard ranks each tag by its measured effect on your mood, with day counts shown, and the answer tends to be lopsided. In our own logs, connection acts were worth roughly three of the others put together, and the awe day did nothing at all. Yours will look different, which is the entire point of measuring.

Why the effect fades, and what to keep

The dose-response finding cuts both ways. More days meant bigger gains in the study, which strongly suggests the gains recede when the days stop. That’s not a flaw in the intervention; it’s how most mood levers work, and the practical response is to keep the two or three acts that measured best and let the rest go. A daily kindness plus a weekly gratitude list is sustainable. Seven rotating acts forever is not.

Two companion ideas fit here. The dopamine menu is a way to keep your winning acts written down for the days you can’t think. And glimmers are the passive cousin of micro-acts: small good moments you notice rather than make, which respond to the same tagging treatment.

MoodKit’s limits, for the record: it won’t send you the day’s act (it’s a tracker, not a prompts app; the journal prompts list is the closest we have), it has no Apple Watch app, and there’s no permanent free tier after the trial ($39.99 a year or $79.99 lifetime). What it adds to the Big Joy Project is the one thing 17,598 participants didn’t get: a verdict about themselves.