11/23/2011 12:31 pm ET Updated Jan 23, 2012

The 'Thanks' in Thanksgiving

Despite our national holiday's links to gluttony, drunkenness and simmering family resentments, it is first and foremost a time to count our blessings. We shouldn't have to be reminded about the importance of routinely expressing our gratitude to others, but it doesn't hurt. After all, words of gratitude are an important social convention, a way of letting others know you value and appreciate them and their support. Plus saying "thank you" is the right thing to do.

Like a lot of parents, I drilled this into my kids from early on. What I didn't teach them -- because I didn't know it at the time -- was how they themselves might benefit from saying "thank you." An emerging body of research is now showing that genuine expressions of gratitude can be tonic not just for the recipient, but for those who are saying "thank you" as well. Indeed, being grateful -- and saying so -- can change the very way we think about our closest relationships.

One scientist who has been rigorously deconstructing gratitude is Nathaniel Lambert of Florida State University. He and several colleagues decided to explore whether the simple act of expressing thankfulness might be linked to a deeper sense of commitment and responsibility toward someone else. To find out, the psychologists recruited a large group of young men and women and gathered information on their most intimate relationships, including the frequency and manner in which they expressed their gratitude toward their partner. They also questioned them about the strength of their relationship, focusing especially on feelings of responsibility for their partner's happiness and welfare.

They wanted to see if there was any connection between thankfulness and the quality of the partnership. And there was, clearly. Those who were more expressive of their gratitude toward their partner saw their commitment as deeper and the relationship as more mutually supportive. They also measured these perceptions six weeks later, to see if gratitude was linked to an increase in relationship quality over time. And, again, it was.

These findings are intriguing -- but limited. They don't say anything about whether expressing thanks actually leads to improved feelings about a relationship. So Lambert and his colleagues decided to run another experiment to sort this out. In this study, they actually manipulated gratitude. They had a group of volunteers deliberately increase their verbal or written expressions of thanks toward a close friend. They were instructed to "go the extra mile" in really demonstrating their feelings of gratitude. For comparison, other volunteers merely thought grateful thoughts -- without expressing them -- while others focused on positive memories of time together. At the end of the three weeks, they compared the volunteers' attitudes toward their relationship.

There was no doubt about cause-and-effect this time. As reported a while back in the journal Psychological Science, those who more frequently spoke or wrote their words of thanks saw their relationship as more mutual and cooperative as a result. Importantly, merely thinking about being grateful did not improve relationships. So words count.

What's going on here? The scientists believe that saying "thank you" sends a message not only to one's partner but to oneself as well. It changes our self-perceptions. The very act of saying "thank you" reinforces one's desire for a mutually supportive relationship and increases dependency, which triggers trust and in turn deepens a relationship. In this way, saying "thank you" initiates a spiral of kindness and appreciation in relationships. And what's more, it's not complicated.