Gratitude practice — deliberately identifying and appreciating what is good in your life — is one of the most robustly supported positive psychology interventions. Robert Emmons and Michael McCullough's foundational research found that people who wrote weekly about things they were grateful for had higher wellbeing, more optimism, fewer physical complaints, and more helping behaviors than control groups. Gratitude meditation extends this by incorporating a contemplative quality — sitting with the felt sense of appreciation rather than just listing things mentally. Neuroscience research shows gratitude activates brain regions associated with reward, moral cognition, and interpersonal bonding.

Reference:

Wikipedia: Gratitude

https://en.wikipedia.org/wiki/Gratitude