Five kind acts in one day: the famous result is unpublished raw data

Bundle your kind acts into one day, the advice goes. It traces to one unpublished student study. A 2018 meta-analysis of 4,045 people says what holds up.

If you have read anything about the science of kindness, you have probably met this piece of advice: don't sprinkle your good deeds across the week, bundle them. Five kind acts on a single day, and you will feel it. Spread the same five thinly from Monday to Friday, and the effect disappears.

It is a lovely finding. Specific, slightly counter-intuitive, and it even gives you a plan for Saturday. It also rests on a foundation that is much thinner than the way it gets repeated.

Where the claim comes from

The usual citation is Sonja Lyubomirsky, Kennon Sheldon and David Schkade, "Pursuing Happiness: The Architecture of Sustainable Change", published in the Review of General Psychology in 2005. It is a theory paper, and a good one. Its central argument is that roughly half of the differences in happiness between people is set-point, a small slice is circumstances, and a meaningful share is what people actually do, which is where the room for change lies.

Near the end, the authors describe two small interventions as "initial existence proofs" for that model. In the first, students were asked to perform five acts of kindness per week for six weeks, "either all five acts in 1 day or five acts spread over the week". The examples were ordinary: giving blood, helping a friend with a paper, visiting an elderly relative, writing a thank-you note to a former professor. A control group just filled in the questionnaires.

The result, as the paper describes it: the control group's happiness went down over the six weeks. The kindness group's went up, "but this increase was evident only among those who showed their weekly generosity all in a single day."

Now look at the reference list. The study is cited as Lyubomirsky, Tkach and Sheldon (2004), with a description in square brackets, and then two words: "Unpublished raw data."

The paper gives a figure, but no sample size, no effect size, no test statistics for the timing comparison. The authors are also frank about the limits. These interventions "notably did not test the sustainability of the well-being increases". Nobody followed the students after week six.

How it grew up

None of this is hidden. Lyubomirsky has been careful about it herself. In a 2013 review with Kristin Layous in Current Directions in Psychological Science, the finding appears as "in one study", and it is paired immediately with a warning in the other direction: counting your blessings worked better once a week than three times a week. Too much of a good activity can go stale.

But the version that circulates in wellness articles, workplace newsletters and kindness challenges has lost the qualifiers. "Research shows" is doing a lot of work in that sentence. One group of students, unpublished, measured for six weeks.

I do not think the idea is wrong. The explanation the authors offered is plausible: most kind acts are small, and five small things spread over a week blur into your normal behaviour, while five on one day feel like an event. I just don't think anyone knows yet whether it is true.

What the larger evidence does say

The better question is whether being kind makes the kind person happier at all, and here there is something much more solid. In 2018 Oliver Scott Curry and colleagues at Oxford published a systematic review and meta-analysis in the Journal of Experimental Social Psychology. They screened 489 articles and kept 27 experimental studies with 4,045 participants in total.

The overall effect of doing kind things on the doer's well-being was, in their words, "small-to-medium", δ = 0.28. They found no sign of publication bias. And the effect was not moderated by sex, age, type of participant, type of intervention, control condition or outcome measure.

That last point is quietly important. The review could not show that one way of being kind beats another. Bundled or spread, strangers or friends, the evidence as it stands mostly says the same thing: doing it helps a little, reliably.

There is one more follow-up worth knowing. A later study by Sheldon, Boehm and Lyubomirsky, from 2012, found that people who varied their kind acts from week to week gained more than people who kept doing the same ones. Repetition dulls. That fits with the blessings result and with everything else we know about how quickly people get used to good things.

So, Saturday

If a kindness day works for you, keep it. It is a perfectly good way to make sure the five things actually happen, which is more than most good intentions manage. Just hold it as a habit you like, not as a law of the mind.

What the evidence supports is plainer and, honestly, more encouraging. Small kind acts make the person doing them a bit happier, across ages and settings. Doing different ones seems to help. Nobody has shown that doing them on the wrong day of the week cancels them out.

Sources: Lyubomirsky, S., Sheldon, K. M., & Schkade, D. (2005). Pursuing happiness: The architecture of sustainable change. Review of General Psychology, 9(2), 111–131. Lyubomirsky, S., & Layous, K. (2013). How do simple positive activities increase well-being? Current Directions in Psychological Science, 22(1), 57–62. Curry, O. S., Rowland, L. A., Van Lissa, C. J., Zlotowitz, S., McAlaney, J., & Whitehouse, H. (2018). Happy to help? A systematic review and meta-analysis of the effects of performing acts of kindness on the well-being of the actor. Journal of Experimental Social Psychology, 76, 320–329. Sheldon, K. M., Boehm, J. K., & Lyubomirsky, S. (2012), as summarised in Lyubomirsky & Layous (2013).