Scientists have discovered which way of expressing gratitude works best

Participants were asked to complete one of six short tasks. For example, to write a letter to someone they were grateful to, to send them a message, to list five things they were grateful for, or to imagine what life would be like without a particular positive event. For comparison, other volunteers carried out neutral tasks unrelated to gratitude. The entire online experiment took around 20 minutes.

Immediately after the exercise, the researchers assessed the participants’ mood, optimism, life satisfaction, envy and certain feelings related to their relationships with others.

Details

The researchers found the most pronounced overall effect when a person wrote and actually sent a message to someone they wanted to thank. A letter that a participant wrote but did not send also proved to be among the more effective options.

However, one of the best-known practices — making a list of five things for which a person is grateful — showed the weakest effect among the six exercises tested.

The authors believe that the social aspect may play an important role. When gratitude is directed at a specific person, the exercise involves not only reflecting on the positive, but also the relationships between people. However, the study does not prove that social contact is the reason for the stronger outcome.

On average, gratitude practices slightly increased positive emotions and optimism, whilst reducing negative emotions and envy compared with the control tasks.

The most noticeable change was in positive emotions, with an effect size of d = 0.37. For optimism, the effect size was smaller — 0.24 — and for life satisfaction, just 0.12. This means that one cannot speak of a sharp increase in happiness after a single exercise.

The study primarily shows a short-term change in a person’s state immediately after the task.

Gratitude had varying effects across different countries

The differences between countries turned out to be even greater than the differences between the exercises themselves. The researchers observed the most pronounced overall effect in Mexico, whilst in Norway the changes were close to zero. Brazil fell roughly in the middle of this range.

The authors investigated a possible link between the results and cultural characteristics, religiosity and social norms. However, these explanations are currently considered preliminary and require further testing.

The most consistent finding across different countries was an improvement in positive mood. For the other indicators, the researchers were unable to speak with the same degree of certainty about a universal effect.

This is not necessarily the case in the long term. The study tested a single short exercise, and participants’ state of mind was measured immediately afterwards. It does not show that practising gratitude daily over a period of months consistently increases life satisfaction or can replace psychological support.

Furthermore, the conclusions are based on the participants’ self-reports – people reported their own emotions and attitudes towards life.

Nevertheless, the scale of the study allows for a more cautious practical conclusion: if someone wishes to try a gratitude exercise, addressing a specific person may have a more noticeable immediate effect than simply listing pleasant events.

Why this is important

Research into gratitude has often been conducted in the US and other Western countries. This new study covered 34 countries with different cultural contexts and showed that the same psychological practice may not work in the same way across different societies.

This is also important for popular psychology: the findings did not reveal a universal exercise that works equally well for all people in all countries.

Source

Study: Nicholas A. Coles et al. A multinational megastudy of the effects of gratitude practices on subjective well-being.

Journal: Proceedings of the National Academy of Sciences (PNAS), 2026, vol. 123, no. 20.