"When the crazy thing years ago was like, 'Women aren't funny,' I thought, 'What cave do you live in?'" McCarthy said at a press conference Thursday for "The Heat."
The raunchy comedy finds the actresses playing two cops who are equally adept with a foul-mouthed wisecrack and a snub-nosed firearm. It is directed by Paul Feig, who previously guided McCarthy to an Oscar nomination in "Bridesmaids."
McCarthy was referring to the late Christopher Hitchens' infamous 2007 Vanity Fair essay, in which he asserted that women dampen their humor to appeal to men.
"Precisely because humor is a sign of intelligence (and many women believe, or were taught by their mothers, that they become threatening to men if they appear too bright), it could be that in some way men do not want women to be funny," Hitchens wrote. "They want them as an audience, not as rivals."
Bullock said that she thinks films like "Bridesmaids" are helping to explode that prejudice by showing that women drop four-letter words and are no stranger to scatological humor just like men.
"Uncensoring women has I think led to more fun on screen," Bullock said.
"'Bridesmaids' felt like it had absolutely no censorship," she added. "It didn’t say women only speak like this, women should behave like this…it was just these funny people having awkward life moments and I think it takes the sex out of it."
McCarthy and Bullock said that part of what appealed to them about "The Heat" wasn't its outrageous humor. It was that both women were competent.
"We had no interest in making [a movie about] two wacky cops that are bad at their job and they’re fighting over lipstick in the car," McCarthy said.
"The Heat" opens on June 27, 2013.