How often do you say “thank you” and really mean it?
According to new research from the University of California San Diego, expressing gratitude does far more than make someone’s day. It can strengthen relationships, boost teamwork, and even help your body perform better during stressful situations.
Christopher Oveis, an associate professor who studies how positive emotions affect health and social behavior, says gratitude has a unique power.
“It benefits everyone involved—the person who expresses it, the person who receives it, and even those who witness it,” he explains. His message is simple: when you feel grateful, say it.
One of Oveis’s studies shows that gratitude can help your body perform at its best when under pressure.
In an experiment inspired by the TV show Shark Tank, pairs of students were asked to pitch a new bicycle design to judges—a stressful task meant to raise anxiety. Before presenting, some team members thanked each other for their help or support.
Those who shared gratitude showed healthier physical responses during the challenge. Their hearts pumped more effectively, their blood vessels widened, and more oxygen reached their brains.
These changes signaled a “challenge response”—a physical state linked to clear thinking and strong performance. In short, people who feel appreciated handle stress better.
Gratitude also strengthens personal and professional relationships. Whether between coworkers, classmates, neighbors, or family members, saying thank you shows people that their efforts matter.
Oveis found that even strangers who exchanged a simple expression of thanks felt more connected and worked better together afterward. Over time, these small moments build trust and closeness.
Teams benefit as well. When people know they are valued, they become more motivated and cooperative. In Oveis’s studies, teams who expressed gratitude before stressful tasks performed better and felt more confident.
Gratitude sends a clear message of support—something that helps any group, from sports teams to office coworkers, perform at their best.
The effects of gratitude ripple outward, too. Witnessing someone express genuine thanks—even if it isn’t directed at you—can make you feel more connected and generous. People tend to want to help, collaborate, and spend time with grateful individuals. For leaders, expressing gratitude publicly can greatly improve team morale and performance.
Oveis also points to research showing that the most meaningful thank-yous focus on the other person’s kindness, not just your own needs. A sincere “You were really thoughtful” resonates much more deeply than “I really needed that.”
As the holidays approach, Oveis encourages people to let their gratitude be heard. Reflecting on what you’re thankful for is good—but actually saying it aloud strengthens relationships and makes everyone feel more connected.
In his words: “If you feel gratitude, let it out. Don’t hold it in.”
