I was reading Elephant Journal and found more proof that laughter is good for us:
I knew this, to some degree, as I once saw a story on a small tribe somewhere (I cannot remember) who all share a small sleeping space. At random times, they wake up and laugh, and then fall back to sleep. Also, In the docu-drama The Secret, a woman who'd been diagnosed with breast cancer started an ongoing mantra "I am thankful for my healing" and allowed no stress to enter her life. Instead, she spent her days sipping tea and watching funny movies with her husband. Just laughing all day. Four months later, her cancer was gone.