Some have expressed frustration that more men within the entertainment industry aren’t speaking up in support of the Time’s Up and #MeToo movements, and Mark Ruffalo has a theory about why that may be happening.

“I think it’s really important,” Ruffalo said in an interview with Buzzfeed’s online morning show “AM to DM”. “I mean, I think that they’re afraid.”

Co-host Julia Walsh, however, wonders what exactly men are afraid of. “I’m not sure,” Ruffalo said. “I think maybe they’re afraid of being accused, I think they may be afraid of feeling like they didn’t do enough or say enough. I’m not sure, but I don’t know why they’re not being asked more.”

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The 50-year-old “Avengers” star admitted that while he sees a “willingness” from men in the industry to speak out, he thinks they may be fearful of not speaking in a manner “that’s respectful about it.”

He added: “It’s a fragility there. A fear of saying the wrong thing and then being called out, but you know, we have to drop our fear and our fragility, because when you’re privileged, you have a voice and right now men are privileged. [Men] have a privilege over women, it’s just the way it is. And so, we have to make a space inside of our privilege, a safe space for women to speak up.”

Ultimately, Ruffalo said he’s hopeful that more males will lend their voices to these movements. “I’m hoping that more and more actors — men — will do it,” he said, adding: “And there are ones that do, it’s just we need more.”