The world’s leading expert on gratitude is Dr. Robert Emmons, a professor of psychology at the University of California, Davis. In a 2003 study published in the Journal of Personality and Social Psychology, Dr. Emmons and his colleague Michael McCullough from the University of Miami examined the effects of writing gratitude diaries on almost 200 college undergraduates. Students were divided into three groups, and each group wrote 10 weekly diaries focusing on gratitude (blessings), hassles and annoyances, or neutral events. Those in the gratitude group were told:
“There are many things in our lives, both large and small, that we might be grateful about. Think back over the past week and write down … up to five things in your life that you are grateful or thankful for.”
At the end of 10 weeks, those in the gratitude condition reported feeling more positive about their lives as a whole, more optimistic about the upcoming week, having fewer physical symptoms, and spending more time exercising. Yet the gratitude condition did not lead to a more positive affect, as the researchers had anticipated.
Perhaps focusing on gratitude only once a week was not frequent enough to change mood. Therefore, the researchers conducted a second study which increased the frequency of the diaries to once daily (for two weeks). They also replaced the neutral life events group with one in which participants wrote about the ways they were better off than other people (known as downward social comparison). These instructions were superficially similar to the gratitude instructions, but not likely to have the same benefits.
Results showed that, as the researchers had predicted, those in the gratitude condition experienced a more positive mood during the two-week period than those in the other groups, and they were also more likely to report doing acts of service, such as helping someone solve a problem or offering emotional support to others. Unlike in the first study, however, there were no benefits of gratitude on symptoms or health behaviors. The researchers concluded that maybe two weeks of gratitude was not enough time to create lasting benefits on health, so they decided to do a third study over a longer period, with a population that actually had more health problems.
The third study asked 65 adults with neuromuscular disease either to write gratitude diaries for a 21-day period or to just fill in the assessments of mood, well-being, and health without actually having an intervention (control condition). Those in the gratitude condition also had their partners rate their mood and life satisfaction.
Results showed that the gratitude group had more positive views of their life as a whole than control participants. They also reported a more positive mood and less negative mood on a daily basis during the study period. Their partners also reported that the gratitude participants had a more positive mood and greater satisfaction with life. With respect to health, the gratitude condition actually improved participants’ sleep— both amount and quality. Perhaps focusing on life’s blessings reduced the worry and angst that keep people awake at night.
In summary, writing gratitude diaries seems to be beneficial no matter what. Specific benefits of gratitude seem to depend on what you’re comparing it to, whether you are healthy or sick, how frequently and over what time period you do the practice. Just two or three weeks of filling out gratitude diaries each evening seems to improve mood, optimistic outlook, and life satisfaction, as well as making you more likely to help others. If you want to gain a health benefit from gratitude, you may need to persist with the diaries for two or three months. This practice takes only five or 10 minutes a day, but when done cumulatively, seems to reorient your mental compass towards focusing on the positive.