In a study in the journal of personality and social psychology in 2003 researchers asked subjects to write a few sentences each week, focusing on particular topics. One group wrote about things they were grateful for that had occurred during the week. A second group wrote about daily irritations or things that had displeased them, and the third wrote about events that had affected them (with no emphasis on them being positive or negative). After 10 weeks, those who kept gratitude journals on a weekly basis exercised more regularly, reported fewer physical symptoms, felt better about their lives as a whole, and were more optimistic about the upcoming week compared to those who recorded hassles or neutral life events.
In a study in 2005 in American Psychologist the researcher tested the impact of various positive psychology interventions on 411 people, each was compared with a control assignment of writing about early memories. When their week’s assignment was to write and personally deliver a letter of gratitude to someone who had never been properly thanked for his or her kindness, participants immediately exhibited a huge increase in happiness scores. This impact was greater than that from any other intervention, with benefits lasting for a month.
In a study in the journal of school psychology in 2008 two hundred twenty one adolescents were assigned to either a gratitude exercise (i.e., counting one’s blessings), a hassles condition, or a control condition. As predicted, the gratitude condition was associated with greater life satisfaction. The authors concluded from their experience that counting blessings seems to be an effective intervention for enhancing well being in adolescents.
In another study in 2008 in the journal of pallative care researchers studied the extent to which the communicative act of love, gratitude, and forgiveness and spiritual and social well being predict the quality of life for end of life subjects. Subjects were all adult hospice patients age 35 to 80 with a diagnoses of cancer living in their homes under the supervision of a large midwestern hospice center. All were given a variety of tools to measure the appropriate study objects. Results showed a Strong, positive correlations among social and spiritual well-being, communicative acts, and the quality of life at the end of life. (p < 0.01) Spiritual well-being most significantly predicted the quality of life at end of life. Although not statistically significant, the communicative acts of love and gratitude made a small contribution to the overall model but The communicative act of forgiveness did not perform well.
Like other researchers, Chen and Kee in 2009 found that gratitude positively predicted life satisfaction among Taiwanese high school athletes, Tseng in 2008 reported in The Bulletin of Educational Psychology that he found an association between gratitude and well being among 270 Taiwanese college students and Froh et al (2009) reported in the Journal of Adolescence that he examined 154 adolescents and confirmed associations between gratitude and life satisfaction.
In a study in Personality and Individual Differences in 2010 the researcher had a sample of 389 adults and examined gratitude and well being in the context of personality style. In this study, gratitude was most strongly correlated with personality attributes related to well being, and the researchers concluded that gratitude has a unique relationship with life satisfaction.
In a 2013 study reported in the Journal of Happiness, researchers studied 27 high gratitude individuals and 40 low gratitude individuals diagnosed with breast cancer. They concluded that gratitude was significantly and positively correlated to post traumatic growth, to psychological well being, positive relations, to symptomatology, relaxation and contentment, and negatively related to anxiety, depression, and hostility-irritability. The high gratitude and the low gratitude group reported significant differences on post traumatic growth and Symptomatology dimensions, but not on Psychological well being, with High gratitude individuals displaying higher levels of post traumatic growth, positive affect and lower symptomatology. They concluded in breast cancer patients gratitude is strongly associated to post-traumatic growth, reduced distress and increased positive emotions, but surprisingly not to psychological well-being.
A 2015 report in the journal of The American Psychological Association found that patients who displayed more outward tendencies towards gratitude slept better, had less fatigue, were less prone to depression and experienced less systemic inflammation.