Indeed, a few exercises in From Rebel to Ruler focus on gratitude. Many long-standing philosophies and religions have gratitude at their cores. In fact, my favorite "happiness hack" is to just stop and list ten things for which I am grateful.
In the book NurtureShock, author Po Bronson describes an exception: middle school kids. Kids ranging from 6th grade to 10th grade showed no reaction to gratitude journals. Diving deeper into the data reveals that happy middle school kids are actually made unhappy by gratitude exercises.
Kids at this age have a drive to feel independent and self-reliant. Gratitude makes you feel connected to other people. For students later in high school and college, who are making decisions about their lives and facing high stakes tests, connection is good. But for energetic, rebellious teens, gratitude makes them feel dependent and limited.
This interesting paradox cuts to the heart of teaching. Adults (non-teachers) will stand on their soapboxes and want to reinvent education around what they find valuable to their lives right now. In the best case scenario, kids will find these lessons boring. In the worst case, it could actually do harm.