 The researchers randomly assigned them to two groups, the control group, which received no appreciation, and the gratitude group. This group received regular visits from the director to personally thank them for their hard work. While both groups received feedback on how they were doing, it was that little bit extra the gratitude group received that made the difference. But more importantly, it was the type of recognition. Instead of just saying thank you, the director said, I am very grateful for your hard work.