It used to be in Hollywood that a surprisingly successful flick would almost immediately spawn a flood of knock-offs that tried to ride the financial coattails of the hit. The many “killer big animal” movies that followed in the wake of Jaws (1975) are the prime example of this. These days, studios are more protective of their property – they’ll make their own sequels and reboots, thankyouverymuch.
Some of the examples are only clear in retrospect; those usually wind up getting their own subgenre. When Whatever Happened to Baby Jane? (1962) blew everyone away thanks to the performances of Betty Davis and Joan Crawford, a number of movies borrowed the idea of a deranged older woman terrorizing people, and the “psycho-biddy” genre came out of that.
Robert Aldrich, who produced “Baby Jane” and another entry in the genre, Hush… Hush, Sweet Charlotte (1964), snarfed up the rights to the 1962 novel The Forbidden Garden by Ursula Curtiss, and turned it into Whatever Happened to Aunt Alice? Geraldine Page and Ruth Gordon were signed to play the protagonists, the aging widow Claire Marrable and her housekeeper Alice Dimmock, respectively.