Celebrations held at harvest time, like Thanksgiving in the USA, have always been a part of most cultures. Romans celebrated a harvest festival that honored Ceres, the goddess of corn, while ancient Greek women honored Demeter, the goddess of grain. Chuseok is the autumn festival in Korea, a national celebration where people return to their hometowns to remember their ancestors.
The human need to express gratitude seems to be a powerful & almost universal phenomenon. We create elaborate rituals & traditions that surround the concept of giving thanks- but why do we do this? That’s exactly what Robert A. Emmons, Ph.D., a psychology professor at the University of California discovered.  The author of Gratitude Works!: A 21-Day Program for Creating Emotional Prosperity. 
Emmons is one of the pioneers of research into the ways that gratitude affects our lives. To assess people’s levels of thankfulness, Emmons & his colleague Michael E. McCullough created a questionnaire that allowed them to compare “grateful people” to those who were less so. They also found ways to cultivate gratitude in test subjects — keeping a “gratitude journal,” counting one’s blessings, writing letters of thanks — then studied the changes that occurred as a result.
“For too long, the concept of gratitude had been ignored,” said Emmons, director of the university’s Emmons Lab, which creates & shares scientific data on gratitude, its causes, & its potential effects on human health & well-being. He calls it “the forgotten factor in the science of well-being."

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