Daylight

Practice · Three Good Things

Three good things, and why each one happened

It's one of the most studied writing exercises in positive psychology, and one of the shortest. The part people tend to leave out is the one the researchers thought mattered most.

Path Integral · 26 September 2026 · 5 min read

  • CadenceSeven nights, gaps allowed
  • SessionA few minutes
  • Based onSeligman, Steen, Park & Peterson (2005)

The practice

Each night, before bed, write down three things that went well that day. Then, for each one, write why it happened. They can be small things: a good cup of coffee, a train that was on time, a conversation that went better than you expected.

The second step is easy to skip, and most versions of this exercise online do skip it. Explaining why a good thing happened asks you to look at your day a little differently. You notice what you did to make it happen, who else was involved, or how much of it was simply luck.

What Daylight puts on the page

Three good things that happened today — small ones count — and why each one happened.

1.
Why it happened:

2.
Why it happened:

3.
Why it happened:

Where it comes from

In 2005, Martin Seligman, Tracy Steen, Nansook Park and Christopher Peterson published a study in American Psychologist testing five short exercises against a placebo. The participants were several hundred adults who had found the researchers' website. The placebo exercise was writing about an early memory every night for a week.

In the Three Good Things group, people wrote three things that went well each night for one week, along with an explanation of why each one happened. The researchers followed everyone up for six months.

What the researchers found

At the end of the week, the Three Good Things group and the placebo group looked much the same. The difference showed up later. Compared with the placebo, the Three Good Things group reported higher happiness and fewer depressive symptoms at the one-month, three-month and six-month follow-ups. The placebo group's early lift had faded within a week.

The researchers noticed something else. The participants whose results lasted longest tended to be the ones who had kept the exercise up on their own after the week was over, even though nobody asked them to.

More often isn't always better

Two other studies are relevant to how often to do this. Robert Emmons and Michael McCullough (2003) asked people to list things they were grateful for once a week for ten weeks. Compared with groups who listed hassles or neutral events, the gratitude group rated their lives more favourably and felt more optimistic about the coming week.

Sonja Lyubomirsky, Kennon Sheldon and David Schkade (2005) described a six-week study with a surprising result. People who counted their blessings once a week showed an increase in wellbeing, while people who did it three times a week did not. One reading is that a practice repeated too often goes stale and turns into a chore.

How Daylight runs it

This is why Daylight runs Three Good Things for seven nights and then stops. That's the schedule that was tested, rather than an open-ended daily habit. Gaps are allowed, so a missed night just moves the run on by a day. When all seven nights are written, the run is complete. You can start another whenever you like, or carry on unprompted, as some of the original participants did.

The prompt appears on the day's page, next to your calendar, so it's there when the evening comes round. Anything you write stays on your iPhone.

How big is the effect? Honestly, modest. A 2013 meta-analysis of positive-psychology exercises by Bolier and colleagues found small average effects on wellbeing and depressive symptoms. It also noted that higher-quality studies tended to report smaller effects. A 2022 review of journaling interventions by Sohal and colleagues reached a similar conclusion. Daylight gives you the method as it was tested and tells you where it came from. It can't promise what it will do for you.

Sources

  • Seligman, M. E. P., Steen, T. A., Park, N., & Peterson, C. (2005). Positive psychology progress: Empirical validation of interventions. American Psychologist, 60(5), 410–421.
  • Emmons, R. A., & McCullough, M. E. (2003). Counting blessings versus burdens. Journal of Personality and Social Psychology, 84(2), 377–389.
  • Lyubomirsky, S., Sheldon, K. M., & Schkade, D. (2005). Pursuing happiness: The architecture of sustainable change. Review of General Psychology, 9(2), 111–131.
  • Bolier, L., Haverman, M., Westerhof, G. J., Riper, H., Smit, F., & Bohlmeijer, E. (2013). Positive psychology interventions: A meta-analysis of randomized controlled studies. BMC Public Health, 13, 119.
  • Sohal, M., Singh, P., Dhillon, B. S., & Gill, H. S. (2022). Efficacy of journaling in the management of mental illness: A systematic review and meta-analysis. Family Medicine and Community Health, 10(1), e001154.