Here is a brief list of research results on gratitude.Each study is briefly described, the results presented, and the reference cited and two great books are recommended (so you can get the article and evaluate the research yourself).
People with an “attitude of gratitude” are in better physical health, sleep better, and spend more time exercising:McCullough and Emmons 2007
DESCRIPTION OF THE STUDY:
McCullough and Emmons randomly assigned participants to three groups. Each participant “completed an extensive daily journal in which they rated their moods, physical health, and overall judgments concerning how their lives were going. …to measure how happy these people were – in other words, what exactly their natural range of was – both before and after…” Every week for ten weeks each participant kept a short journal. “They either briefly described, in a single sentence, five things they were grateful for that had occurred in the past week (the gratitude condition), or they did the opposite, describing five daily hassles from the previous week (the hassles condition) that they were displeased about. The neutral group was simply asked to list five events or circumstances that affected them in the last week, and they were not told to accentuate the positive or negative aspects of those circumstances (the events condition).”
“Those in the gratitude condition reported fewer health complaints and even spent more time exercising than control participants did. The gratitude group participants experienced fewer symptoms of physical illness that those in either of the other two groups. Lastly, there was a main effect for hours of exercise: people in the gratitude condition spent significantly more time exercising (nearly 1.5 hours more per week) than those in the hassles condition”. They also studied people with Neuromuscular disorders (mostly people with post polio syndrome) and found “the participants showed significantly more positive affect and satisfaction with life, while also showing less negative affect than the control group. …Compared to those who were not jotting down their blessings nightly, participants in the gratitude condition reported getting more hours of sleep each night, spending less time awake before falling asleep, and feeling more refreshed upon awakening.”
Book: R. A. Emmons (2007) Thanks! How the new science of gratitude can make you happier. New York: Houghton Mifflin.Original study: Emmons, R. A. & McCullough, M. E. (2003) Counting blessings versus burdens: An experimental investigation of gratitude and subjective well being in daily life, Journal of Personality and Social Psychology 84: 377-89.
People with an “attitude of gratitude” have lower levels of stress hormones in their blood:R. McCraty, B. Barrios-Choplin, D. Rozman, M Atkinson & A. D. Watkins (1998)
DESCRIPTION OF THE STUDY:
45 adults were taught to “cultivate appreciation and other positive emotions.” “Salivary DHEA/DHEAS and cortisol levels were measured, autonomic nervous system function were assessed and emotions were measured using a psychological questionnaire. Individuals were assessed before and 4 weeks after receiving training in the techniques.
There was a mean 23% reduction in cortisol and a 100% increase in DHEA/DHEAS in the Ss. Increased coherence in heart rate variability patterns were measured in 80% of the S’s during the use of the techniques.”
The original study can be found by looking up: R. McCraty, B. Barrios-Choplin, D. Rozman, M Atkinson & A. D. Watkins (1998) The impact of a new emotional self-management program on stress, emotions, heart rate variability, DHEA and cortisol. Integrative Physiological & Behavioral Science. 32 (2) 151-70.
People with an “attitude of gratitude” undo the cardiovascular after effects of negative emotions:C. Branigan, B. L. Fredrickson, R. A. Mancuso, & M. M. Tugade (2000)
DESCRIPTION OF THE STUDY:
Positive emotions are hypothesized to undo the cardiovascular after effects of negative emotions. Study 1 tests this undoing effect. Participants (170 university students) experiencing anxiety-induced cardiovascular reactivity viewed a film that elicited (a) contentment, (b) amusement, (c) neutrality, or (d) sadness. Contentment-eliciting and amusing films produced faster cardiovascular recovery than neutral or sad films did. Participants in Study 2 (185 university students) viewed these same films following a neutral state.
show that positive emotions can undo the effects of negative emotions and disconfirm the alternative explanation that the undoing effect reflects a simple replacement process. Findings are contextualized by Fredrickson’s broaden-and-build theory of positive emotions.
C. Branigan, B. L. Fredrickson, R. A. Mancuso, & M. M. Tugade (2000) The undoing effect of positive emotions, Motivation and Emotion 24: 237-58.
TWO WONDERFUL BOOKS WE RECOMMEND HIGHLY:
Thanks! Now the new science of gratitude can make you happier by Robert A. Emmons 2007 New York: Houghton Mifflin. We quote from his book above and highly recommend it for further reading on the topic of gratitude.
Positivity: Groundbreaking research reveals how to embrace the hidden strength of positive emotions, overcome negativity and thrive by Barbara L. Fredrickson 2009 New York: Crown Publishers. In addition to explaining the research, Dr. Fredrickson teaches how to use the research results in your daily life.