On Thanksgiving, a national holiday revered by many in this country, we are traditionally reminded to give thanks for all we have in our lives. Often, friends and families will go around the table before beginning the ritual of feasting and ask each person to say what they are thankful for.

The tradition supposedly dates back to a time when the Pilgrims, along with their Native American hosts, joined forces with them to express their gratitude for getting through the difficult first months in the colonies. This history has been unfairly tarnished as we have learned more about how later settlers mistreated the Native Americans and robbed them of their land. (Our recent post traces the controversial history of the holiday as recounted in Melanie Kirkpatrick’s book Thanksgiving: The Holiday at the Heart of the American Experience.)

Nevertheless, the Thanksgiving holiday serves as an important reminder that we are blessed with many gifts. And recent research in the field of Positive Psychology, which focuses on the healthy traits rather than the pathological ones, has uncovered that gratitude plays a central role in our sense of well being and happiness. This sounds simple, and it is, but “practicing gratitude” requires effort and attention. Basically, positive psychologists have found that asking people to develop habits such as keeping “gratitude journals” in which they write down the things that make them feel grateful, can have significant efforts. The simple act of doing this can boost mood, energy, self-esteem, generosity, and even physical health. Researchers Robert Emmons and Robin Stern write:

“Whether in terms of enhancing mental health or preventing mental illness, gratitude is one of life’s most vitalizing ingredients. Clinical trials indicate that the practice of gratitude can have dramatic and lasting positive effects in a person’s life. It can lower blood pressure, improve immune function, promote happiness and well-being, and spur acts of helpfulness, generosity, and cooperation. Additionally, gratitude reduces lifetime risk for depression, anxiety, and substance abuse disorders. Whether it stems from the acceptance of another’s kindness, an appreciation for the majesty of nature, or a recognition of the gifts in one’s own life, gratitude enhances nearly all spheres of human experience.”

And it seems that the more often and more diligently we pursue this activity of “active” gratitude, the bigger the effects. Not only that, but the farther you take the exercises, the more potent the effect. So if you go farther than keeping a journal and actually take steps to express your gratitude directly to someone, you will feel even better.

All this is not to say that it will work if your feelings are insincere or mechanical. To be grateful, you must think about things that are actually meaningful to you and focus on the feelings they inspire. For example, it may not be enough just to say, “I’m grateful for the food we eat”—this can be enhanced by actually imagining all the effort that goes into the planting, growing, delivery, and inspection of these foods.

Positive psychologists such as Martin Seligman, a University of Pennsylvania professor who is considered the father of the movement, suggest that focusing on the here and now is also useful. Look at the past week and come up with ten things that you are grateful for. This helps to connect you to the immediacy of your good fortune.

Like the Pilgrims, we often feel gratitude most acutely after having been through a period of suffering. Emmons and Stern have found that “some blessings are not known until they are lost. Losing some aspects of one’s life may lead the person to increase the value they see in other aspects of life . . . Affliction or suffering are redeemed by the recognition of goodness received, accompanied by powerful feelings of relief and gratitude.”

Gratitude has been found to be redemptive and healing, especially after loss. Psychologists think that “contrast” is one way this works. Going from a state of loss to one of recovery helps us appreciate what we have. Comparing yourself to the less fortunate has always been a way to understand your blessings, but comparing now to a time in your life that was not as happy can also work. It can be something major, like “I’m grateful that my chemo helped me get a remission,” as well as “I’m grateful for the nurses who cared for me.”

Yet we don’t need to have endured tragedy in order to feel the warmth of gratitude. You can focus on being grateful that you have a better boss than you did last year, or on how good it is that your friend decided to stay close by rather than move away.