After his 2014 Un Certain Regard prize-winner “Force Majeure,” Swedish helmer-writer Ruben Östlund takes on the competition with “The Square,” a language satire and social commentary starring Dominic West, Elisabeth Moss and Terry Notary. Alissa Simon

Where did your interest in social behavior come from?

Maybe it was because of my parents. My mother was a teacher in primary school. I remember when I was quite young she had this experiment with her class [where] they point at lines and say which line was the longest, to show social conformity within groups. That also became a scene in [Ostlund’s 2008 feature] “Involuntary.” I guess that’s a part of it — an awareness about these things from childhood and parents that were interested in these topics.

As in “Force Majeure,” “The Square” includes a very powerful set piece that will have people talking. To me, it felt like a metaphor for life in Trump’s America, but what is it about for you?

When we shot that scene, no one had a clue what would happen in America. For me, it is very much about the bystander effect. When we are in public spaces and don’t know who’s in charge, we have a problem with taking responsibility. For me, it was a way to point out how we are herd animals, how we are paralyzed when something happens that we are scared of and the feeling is, “don’t take me, don’t take me, take someone else!”

How long did it take you to shoot that particular scene with the stunning performance by Terry Notary?

It took us three days. After we were finished, Dominic West said that the performance that Terry Notary did was the best performance that he had ever seen. I think it was the feeling of everybody on set — around 300 extras. Every time Terry entered that room, he was so present in this situation that everyone related to the scene in a very, very strong way.

This is the first time that you’ve cast a number of English-speaking actors. Would you be interested in directing in English?

We decided quite early that “The Square” should be a Scandinavian film. I work with Danish and Norwegian actors, not only Swedish. But then I went to London to meet a couple of English-speaking actors that I was interested in. Elisabeth Moss and Dominic West were the best in the improvisations we did on those parts. I was a little bit nervous about starting working with English-speaking actors because I didn’t know how sensitive my instrument would be when I’m directing, if I could lose some nuance. But now that I have the experience, I’d definitely be interested in continuing working in English. But it’s very important that I have a production that I control and the way that we want to shoot the film. So, I don’t think I will go to the U.S. if we aren’t in control of the production and the shooting.