I suppose that I am one of those people who get more out of watching a movie rather than reading the novel. This remains true with Henry James's 1880 Washington Square and William Wyler's 1949 film The Heiress. Although I did enjoy the book, I felt that the cinematic adaptation gave me a much better sense and understanding of the characters and their different personalities.
A main reason I think that this is true is the different endings in the film and in the novel. At the end of the book, Morris comes back after a number of years and once again asks Catherine to marry him. The book ends when she refuses and turns him down. In the film, however, after Morris (Montgomery Clift) proposes to marry Catherine (Olivia de Havilland) again, instead of turning him down, she tells Morris to come back later that night. When Morris does return, he finds that Catherine has had the maid, Maria (Vanessa Brown) lock the door and has stood him up just as he had done to her a couple of years earlier.
In the book, my impression of Catherine is a naïve, typical teenage girl that believes that the boy she is infatuated with hung the moon and is in love with her, not her money. She feels that he genuinely wants to be with her and would do whatever it takes to be with her. She seems to keep this persona throughout the entire book. In the beginning of the movie, Catherine's personality seems to match the one given to her by James in the novel. However, in the film, as it progresses, so her character and her personality. She almost seems to "grow up." By the end of the movie, the once naïve and sheltered girl seems to have been transformed into a bitter, vengeful woman.
By the movie's end, Catherine has changed so much that even her once perky high-pitched voice has altered into a lower, threatening tone. She has devised an elaborate plan to seek revenge on Morris-and it is only after this plan is carried out, that we see a hint of satisfaction as she ascends the staircase, carrying her lamp torch in triumph to her room.
I feel that the movie did a better job of portraying Catherine than the novel did. I am convinced that the movie made her character more interesting by giving her an edginess and showing how she has changed so dramatically over the years.