The 1939 movie Wuthering Heights, directed by William Wyler, diverges from the original 1847 novel, Wuthering Heights, by Emily Brontë in several glaring and possibly necessary ways. The most striking involves the lagging development of the characters Hindley, Heathcliff, Cathy, and the children, Hareton, Cathy, and Linton.
As played by Rex Downing and Laurence Olivier, Heathcliff's character was downplayed in the movie, becoming much more tolerant, victimized, empathetic, and far less aggressive. I think this was done largely to maintain a belief from the audience that Heathcliff was not absolutely crazed with bitterness but rather heartbroken and still attractive to a much tamer and heartbroken Cathy (Sarita Wooten/Merle Oberon). Her obsession with Heathcliff is far more recognizable in the novel, so it is easier for author Emily Brontë to rough-up Heathcliff's demeanor and sensibility. As depicted by Douglas Scott and Hugh Williams, Hindley's character also develops differently in the film from the way it does in the novel. The movie sluggishly turns Hindley into a coward through years of bitterness and alcoholism. The novel confesses a cowardly Hindley very early on; as early as childhood.
The only character who died in the movie until the very end was Cathy. I suppose this was done for simplicity's sake. Cathy's death had to come at the film's climax and essentially be the climax. Additional character deaths, such as those of Hindley, Edgar (David Niven), and Isabella (Geraldine Fitzgerald) may have diluted or hindered such a successful scene. Heathcliff's off-screen demise comes almost as an anticlimax when it is described by Dr. Kenneth (Donald Crisp) to Ellen Dean (Flora Robson) and Lockwood (Miles Mander).
One final notable difference was the children. The children, Hareton, Cathy, and Linton, were never even mentioned in the movie, which is very interesting, provided that the novel uses the spawn of the main characters to tie up the plot and existing dynamic between Heathcliff and Cathy. This seems unfortunate for the film and to the overall plot since the children are what bring the story full circle. Without the children's future relations, Heathcliff and Cathy's relationship was basically all in vain.