One Flew Over the Cuckoo's Nest is considered to be one of the greatest American films. Ken Kesey participated in the early stages of script development, but withdrew after creative differences with the producers over casting and narrative point of view; ultimately he filed suit against the production and won a settlement.  Kesey himself claimed never to have seen the movie, but said he disliked what he knew of it,  a fact confirmed by Chuck Palahniuk who wrote, "The first time I heard this story, it was through the movie starring Jack Nicholson. A movie that Kesey once told me he disliked." 
The power of laughter resonates throughout the novel. McMurphy’s laughter is the first genuine laughter heard on the ward in years. McMurphy’s first inkling that things are strange among the patients is that none of them are able to laugh; they can only smile and snicker behind their hands. Bromden remembers a scene from his childhood when his father and relatives mocked some government officials, and he realizes how powerful their laughter was: “I forget sometimes what laughter can do.” For McMurphy, laughter is a potent defense against society’s insanity, and anyone who cannot laugh properly has no chance of surviving. By the end of the fishing trip, Harding, Scanlon, Doctor Spivey, and Sefelt are all finally able to participate in real, thunderous laughter, a sign of their physical and psychological recovery.