What are the motifs in One Flew Over the Cuckoo's Nest by Ken Kesey?

I think laughter is a motif that brings more healing than anything Nurse Ratched has to offer. McMurphy notes that none of the patients laugh. He uses a myriad humour types to bring these men to life again. He uses dirty humour, sarcastic humour, and even silly humour to, much to Nurse Ratched's chagrin, bring these men a little closer to their former selves.