Hathaway explained that she studied Lamarr's distinctive acting style by watching many of her films while she prepared to play The Dark Knight Rises' enigmatic rogue.
"I know this sounds odd, but her breathing is extraordinary," the star told The Los Angeles Times. "She takes these long, deep, languid breaths and exhales slowly."
Hathaway added: "There's a shot of her in [the 1933 film] Ecstasy exhaling a cigarette and I took probably five breaths during her one exhale. So I started working on my breathing a lot."
Hathaway once again defended Catwoman's Dark Knight Rises costume and newly-designed goggles, which were criticised by some fans when pictures of the outfit were first released.
"I love the costume because everything has a purpose, nothing is in place for fantasy's sake, and that's the case with everything in [director] Christopher Nolan's Gotham City," the actress said.
Hathaway follows in the footsteps of Michelle Pfeiffer and Halle Berry, who both played Catwoman on the big screen, and the three actresses who starred as the villain on the 1960s Batman series and film, Julie Newmar, Lee Meriwether and Eartha Kitt.
The Dark Knight Rises, which also stars Christian Bale and Tom Hardy, will be released in theatres on July 20, 2012.
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View pictures of Catwoman stars through the years below: