Human behavior isn’t always pretty. Darren Aronofsky makes sure we never look away.

Director Darren Aronofsky has a reputation for making audiences squirm. His audacious visual style and knack for pushing psychological buttons have allowed viewers to experience what it’s like to be a perfectionist ballerina trying to retain her sanity (Black Swan), drug users whose lives descend into hallucinatory chaos (Requiem for a Dream), an aging fighter unable to quit the ring (The Wrestler), and more. Lately, he’s been pushing himself—into new genres like National Geographic documentaries and YA literature. Aronofsky spoke from a shoot in Africa about balancing organization with improvisation, his upcoming film, The Whale, and the beauty of the internal monologue.

Fast Company: You’re in Zambia right now. What brought you there?

Darren Aronofsky: I’m in the Lower Zambezi National Park for a show I’m doing for Nat Geo [called Sentient]. We’re filming a pack of wild dogs, sometimes called [African] painted dogs. There’s a large pack of them, about 40. They hunt really big game. But before they go out and hunt, they actually vote in a unique way, to make the decision [about whether] to go out and hunt. The show is about animal intelligence, how the pre-21st-century idea that we’re very different from animals is untrue.

Environmentalism has been a focus of yours since high school, when you spent time in Kenya studying at the School for Field Studies. It’s woven into some of your films, such as Noah and Mother! You’ve also been producing numerous shows for Nat Geo. Has this been a conscious career evolution for you?

I’ve been a big fan of National Geographic my whole life. I subscribed as a boy and had those yellow-bordered magazines on my shelf. Getting to be more explicit with my activism [traveling to the Arctic to bring attention to drilling there, penning a New York Times op-ed about climate change] has been great because, unfortunately, this situation is really tough. It’s an all-hands-on-deck moment. I’m just trying to do anything I can to help.

In your new film, The Whale—which is based on the play of the same name by Samuel D. Hunter and hits theaters this fall—Brendan Fraser plays an obese man on the way to eating himself to death. He’s trying to mend relationships in his life. As a society, we’ve made progress in terms of destigmatizing body size, but there is still a lack of understanding, and prejudice. Were you nervous about tackling such a sensitive subject?

We spent a lot of time educating ourselves. There’s an organization called the OAC (Obesity Action Coalition), and they connected us with people who are living with obesity or for whom obesity has changed their lives in many different ways. To be clear, there are many people who are large and who are very, very happy and have a very positive outlook on the world. I think with this movie, it’s one story. For me, the greatest thing about film is that it’s an exercise in empathy. That feeling when you’re inside someone else’s head that is completely different from [yours]. I never danced ballet, and I never jumped off the top rope [in a wrestling ring], and I was never a drug dealer or user. So it’s about going on a journey with people and getting in their heads. That’s what brings us more together.

As a director, what’s in your own head when you show up on set on the first day? Do you have every detail worked out?

I don’t believe that whole myth of having a pre-thought-out plan. I don’t get that. I think you have to make things up in the moment, because no matter how much you can picture and imagine something, when you’re actually in that three-dimensional space with real people and real equipment and real actors . . . you have to allow the smells that are coming into the room or the mood that’s happening or the heat—they’re going to affect things. You have to be ready to capture and work with it all.

And yet you’re also known as someone who’s extremely organized and precise. You once said that if you weren’t a director you would have been a baseball umpire. How does this element of your personality play into your job?