Directed by Howard Hawks, the 1952 screwball comedy Il magnifico scherzo (Monkey Business) stars Cary Grant as a chemist whose youth elixir causes chaotic, infantile behavior among adults after a chimpanzee contaminates the water supply. The film is noted for its fast-paced "battle of the sexes" dynamics, featuring standout performances from Grant and Golden Globe-nominee Ginger Rogers, alongside an early, iconic role for Marilyn Monroe. You can find more details on IMDb.