Mega-study analyzes the impact of gratitude interventions

Research conducted in 34 countries compared six practices designed to foster gratitude with three control measures, observing variations in effects based on cultural differences.

By Frances Jones  |  Agência FAPESP – Are some interventions designed to induce gratitude more effective than others? In which countries and cultures do they work best to improve mood, strengthen bonds between people, and promote social reciprocity? A study aimed at answering these questions – conducted in 34 countries with over 10,000 participants – had its results published in May in the scientific journal PNAS. In Brazil, the project received the help of researchers and 598 volunteers who responded to intervention prompts via an online tool.
 
“One of our main overall findings is that all the proposed interventions worked,” says Paulo Sérgio Boggio, a psychologist, professor at Mackenzie Presbyterian University, and coordinator of the National Institute of Science and Technology in Social and Affective Neuroscience (INCT-Sani). Boggio and his former graduate student, Beatriz Bezerra de Souza, who received support from FAPESP for her master’s degree, are the two Brazilian co-authors of the article. Thirty-six researchers are listed as authors of the paper, including experimental psychologist Michael McCullough, a professor at the University of California, San Diego. The study was coordinated by Nicholas Coles, a researcher at the University of Florida. 
 
Of the six interventions tested in various countries, the one that had the greatest effect was suggesting that people write and send a message to someone they were grateful to. Conversely, the intervention with the least impact was the most popular one: making a list of five things for which one is grateful. The other interventions were writing a letter to someone you’re grateful to but not sending it; practicing Naikan reflection (writing about three things that happened the previous week and reflecting on what you received, what you gave, and how you could help more); thinking about and writing down five things that happened the previous day for which you’re grateful and imagining what your life would be like without them; and writing a letter to God, a higher power, or a spiritual entity thanking them for what you’ve been given.  
 
“The greatest effect occurred when social connection explicitly came into play. The issue of social connection is central,” Boggio comments on the results. According to the researcher, all six interventions designed to induce gratitude had a greater impact than the three control practices, which consisted of simply answering a questionnaire, writing generally about a past event, or writing about recent interesting events. “For an intervention to be more effective – to have a greater impact – it must be more than just thinking about something good,” says the researcher. 
 
The authors found that gratitude interventions led to immediate and measurable improvements in psychological states linked to what is known as human flourishing. They observed increases in positive affect and feelings of social reciprocity, reductions of negative affect and envy, as well as greater life satisfaction and optimism. 
 
Although there was variation related to the different interventions, the greatest variation occurred when comparing countries. The practices had a greater impact in Mexico but almost no impact in Norway. Brazil fell in the middle of the scale, according to the study. The degree of impact of the proposed measures was influenced by cultural rigidity or flexibility, distance from power, and the population’s religiosity. Some effects of gratitude practices proved more universal than others. For example, feeling more positive was an almost universal effect of the interventions.
 
According to Boggio, the study contributes to the discussion about why people feel gratitude from an evolutionary perspective. “Gratitude is an emotion with a very strong social component. Feeling grateful increases the likelihood that you will help others – and not necessarily the person who helped you,” he says. “This creates a spiral of helping among people, not necessarily because there’s an expectation of direct gain.”
 
One of the effects measured in the study was the feeling of reciprocity. “Our ‘thank you’ can be understood in various ways. One is that we feel obligated to reciprocate, to do good for the other person, to return the favor,” the researcher comments. “So much so that there are people who, when they receive something for which they’re very grateful, experience both the positive feeling and, at the same time, the sense that they’re in debt.” According to Boggio, gratitude helps form bonds and connections. 
 
Now the researchers are seeking to understand whether the wide variation in responses across countries is linked to local social norms or if a way to induce gratitude through country-specific interventions still needs to be found. “How can we induce gratitude in Norway? And in Japan?" he asks, citing countries where these practices had little impact. 
 
Boggio points out that this large-scale study, conducted in collaboration with several countries, is important for shifting the focus away from data primarily from Western countries, particularly the United States. “About 50% of studies on gratitude originate in the United States. The idea was to move away from that and apply the test in countries with a wide range of cultural backgrounds.”  
 
All raw data from the study can be found on the Open Science Foundation website. 

The article “A multinational megastudy of the effects of gratitude practices on subjective well-being” can be read at www.pnas.org/doi/10.1073/pnas.2537789123.