Historically, the field of psychology focused on mental illness and dysfunction. Positive psychology developed as a unique new subdiscipline as recently as 1998. Instead of investigating the question of what went wrong, positive psychology seeks to understand the fulfilling aspects of the human experience.

One aspect of life that has received much attention in this new field is the expression of gratitude. According to PsycNET, the database that indexes much of the psychological research, there were only 30 articles from 1989 to 1993 that dealt in any way with gratitude. In the next five years the number doubled to 66. The redoubling has continued every five years, so that in the current stretch from 2009 to 2013, there have been more than 640 articles dealing with gratitude. The science of mental processing has finally caught up to Abraham Lincoln and our national holiday.

In their recent article, “Gratitude as a Psychotherapeutic Intervention,” which appeared in the August 2013 edition of the Journal of Clinical Psychology, psychologists Robert Emmons and Robin Stern reviewed the research on the benefits of gratitude. They conclude that there are dramatic and lasting benefits in both the physical and psychological realms. For example, in the physical domain, gratitude can lower blood pressure, improve immune functioning, and increase energy. In the psychological realm, gratitude has been shown to reduce depression, anxiety, and substance abuse. Gratitude has also been shown to protect from the destructive impulses of envy, resentment, and bitterness, and may even offer some protection against psychiatric disorders. On the positive side, gratitude promotes happiness, altruism, joy, love, and enthusiasm. In fact, research suggests that the effect of gratitude is larger than the effects of optimism, hope, or compassion.

It turns out that my mother was very wise when she suggested I should be more thankful. Unfortunately, this lesson didn’t take with me. I am much more likely to ruminate about what went wrong than I am to be thankful for what went right (not to mention being grateful for those aspects that seem to have gone wrong). The research, however, suggests that it is not too late for me. Simple research manipulations, in which subjects were assigned journaling exercises to write down grateful thoughts on a daily basis, were effective in bringing about change. In some studies, the manipulations of these simple strategies resulted in significant increases in happiness and decreases in depression.

Modern church choruses suggest to children that we need to practice the attitude of gratitude, and they are right. Practicing gratitude can impact our relationships with those around us and with our God. Perhaps the strong effect of gratitude is because it is inherently relational rather than being self-centered. Gratitude is an expression of selflessness as I move beyond the core selfishness of my being and express thanks to my creator and to those around me. It is, at its very roots, a humble act. As G. K. Chesterton wrote, “The proper form of thanks is some form of humility and restraint.”

We are instructed by the Apostle Paul to make gratitude a ubiquitous part of our lives: “Always giving thanks to God the Father for everything, in the name of our Lord Jesus Christ” (Ephesians 5:20). Always. Everything.

Though we celebrate Thanksgiving Day but once a year, let us remember that practicing gratitude as a regular daily habit (always and everything) is an essential part of the positive human experience. Gratitude is a spiritual act used by God in transforming us through the struggles of the human condition and to enable a positive resting in the work of Christ. Let the habit of gratitude transform your being and your relationships. Always and everything.

Dr. Gary L. Welton is assistant dean for institutional assessment, professor of psychology at Grove City College, and a contributor to The Center for Vision & Values. He is a recipient of a major research grant from the Templeton Foundation to investigate positive youth development.