And he's especially proud of this one because, as he says, "It has no actor-y moments." It follows journalists trying to find the truth about how the Catholic Diocese in Boston covered up child abuse, but director-cowriter Tom McCarthy avoids sensational details to focus on the riveting story.

"I loved that about it," Ruffalo says. "That it is all subtext. There are a few places where the character's personal lives come into view, but not many. In that sense it's also a reflection of their lives at that time, because they didn't have any lives They just had the hunt for the story."

Michael Keaton, Mark Ruffalo and Rachel McAdams all star in Spotlight

Ruffalo feels that he has a responsibility as an artist to tell stories that make a difference. And since he has a Catholic background, Spotlight resonated especially strongly. "A long time ago, I felt the church I experienced wasn't observing the teachings I'd read about," he says. "When I left my Catholic school, I was around 10 or 11 years old, and it started to unravel for me there. I was seeing things that were not in line with what I'd been taught about Jesus. It didn't jibe with me."

When he looked into the story, he was fascinated by how, before the Spotlight team took it on, Boston journalists and officials had simply looked the other way. "It's not what you want to think about your media," Ruffalo says. "I know people don't like journalists, but I actually hold them in very high regard - I am talking outside of gossip, of course!"

And he's also aware that he shares this responsibility. "For actors, like it or not, their voices carry deeply into the culture," he says. "People look towards them for attitudes, for right or wrong."

And of course, with his role in the last two Avengers movies, he knows that his own status is rising. "I get recognised more now. More requests for selfies. My wife has noticed it," he laughs. "But for every 100 people who go and see an Avengers film, if even five, two, whatever, get active. Mostly it's just appealing to people's sense of possibility, that we do create the world we want. I hope that when they see an actor step up, it emboldens them."

Watch the trailer for Spotlight: