Motifs in the James Bond film series the degree to which Bond girls are pivotal to propelling the plot forward varies from one film to the next. Five of the Bond girls are "bad" girls (or at least working for the villain) who turn "good" (or switch sides) usually due to Bond's influence. Bond has fallen in love with only Tracy di Vicenzo in "On Her Majesty's Secret Service" and Vesper Lynd in "Casino Royale", but both of them die at or near the end of the respective films. Roald Dahl, a screenwriter of "You Only Live Twice", said he was given a formula to work to
Motifs in the James Bond film series for the film: "you put in three girls ... Girl number one is pro-Bond. She stays around roughly through the first reel of the picture. Then she is bumped off by the enemy, preferably in Bond's arms." The next girl is anti-Bond and normally captures him, but Bond will save himself by using his charm and sexual potency: she is normally killed midway through the film. Girl number three will survive and end the film in Bond's embrace. Academic Kimberly A. Neuendorf notes that James Bond promotes stereotypical, sex-typed male attitudes, especially when interacting with women and in doing so