Trivia: Julie Harris was very aloof during filming and would often ignore her co-stars behind the scenes - especially Claire Bloom. Bloom felt very hurt by this. However, after filming, Harris showed up at Bloom's house with a gift and revealed that she actually really liked Bloom and her other co-stars. She behaved as she did during filming because she was trying to stay in-character between takes, and was worried that her performance as an outsider would suffer if she was friendly with her co-stars.
Trivia: Patricia Neal won the Academy Award for Best Actress for her role as Alma Brown, even though she's only on screen for a total of 21 minutes and 51 seconds. This is the shortest performance ever to win the Award.
Trivia: The film was to have run six hours with two intermissions, but it was cut down to four with one.
Trivia: Sorrell Booke plays Alan Alda's father in the movie, even though in real life he's only six years older than Alda.
Trivia: Lionel Jeffries was only 5 years older than June Thorburn, who plays his daughter.
Trivia: Anthropology Professor Robert Orwell Sutwell is writing a book about the sex habits of teenagers. His secretary tells him, "Hang on to the movie rights. American-International will snap it up in a minute." American-International is the real-life Los Angeles studio which produced several teen-oriented films, including "Reform School Girl," "Hot Rod gang," "I Was A Teenage Werewolf" - and "Beach Party."
Trivia: The Chinese extras cast in this film were almost all Spanish residents, especially in Madrid. This was done to such an extreme extent that some Chinese restaurants and other Chinese-Spanish-owned businesses in the Madrid area especially were forced to close for a few days due to lack of personnel.