Investigating Sex is a 2001 comedy-drama film written and directed by Alan Rudolph, starring Neve Campbell, Til Schweiger, Nick Nolte and Dermot Mulroney. The film is based on Investigating Sex: Surrealist Research 1928-1932, a book of Surrealist writers' discussions about sex led by André Breton and compiled by José Pierre. Rudolph called it "one of the most horrific experiences I've ever had, yet this was combined with one of the most pleasurable and enjoyable and creative experiences."