Three-time Oscar winner Meryl Streep told young actors at the Berlin film festival Sunday that Hollywood would never resolve the diversity row until studio boardrooms became less white and male.
Giving a masterclass for 300 budding actors from around the world at the cinema showcase, where Streep is serving as jury president, the most acclaimed US film actress of her generation was asked whether sexism and racism in show business had waned over her four-decade career.
"I think it's moving in a very positive direction. I think you have to make noise to have room at the table, for people to move aside and let you pull your chair up to the conversation," she said.
"But in our industry it will always depend on diversity in the boardroom. So all the talk about the lower levels of endeavour -- if the decisions are only made by one group of people whose tastes will decide which kinds of films are made, then only certain kinds of films will be made."
Streep lamented that it was hard to get "40 to 50-year-old white males to be interested in stories about their first wives or their mothers".
"They don't feel invested in this journey and yet younger men are and that's good," she said.
The movie industry is embroiled in a bitter debate about unequal pay between the sexes and a shut-out for non-white actors in the main acting nominations for this month's Academy Awards, for a second year in a row.
'Hags and witches'
Streep, 66, landed in hot water on the opening day of the Berlin festival when she was asked whether she felt qualified to judge Middle Eastern films and responded by emphasising human beings' common origins.
"I've played a lot of different people from a lot of different cultures and the thing that I notice is that there is a core of humanity that travels right through every culture," she said.
"And after all we're all from Africa originally. You know, we're all Berliners, we're all Africans really."
Critics using a #wereallafricans hashtag on Twitter called the comment tone-deaf, while others defended her as trying to call for greater inclusion.
Streep said Sunday she had been surprised by her career's longevity, expecting sexism to thwart her much earlier on.
"I always thought my career was over starting at 38 years of age," Streep said.
"In those days I had no reason to think that I would work past 40. You could work to 40 and then you start playing hags and witches," she said.
"That's one reason I didn't play a witch until 'Into the Woods' (in 2014) - and I had been offered many. It's that trough that women fall into when they're no longer fertile or fuckable, whatever that word is."
Streep advised the acting students not to become too attached to their sex appeal if they hoped to go the distance.
"You can't have a long career and play a lot of different kinds of characters of all different ages and maintain your magazine cover vanity," she said.
"It's stupid and it's superficial and it's unartistic and who cares?" she said to cheers from the young audience.
Rather die than direct
Asked if she would follow the long trail of acting colleagues from Clint Eastwood to Angelina Jolie into directing, Streep quipped: "Some of my directors would say that I already have," referring to her own hands-on style on set.
"But no, I think it's two different muscles," she said.
"I'm not that quick on my feet to be able to walk around and choose a lens and then," she said, striking a pose.
"It is also a, to me, much more boring job. I don't care where they put the toilets, I'm an actress. I don't have to put on a puffy jacket at four in the morning and location scout. I'd rather die."
Streep joked that her late friend Mike Nichols, who directed her in several films including "Postcards from the Edge" and "Silkwood", used to "drill" her about how other filmmakers worked.
"I told him it's like asking about the other boyfriends, 'Does he do it better than I do?'," she said.
"They are all different. It's the most interesting thing about having a long career, seeing how many different ways there are to get a good result."