In M. Night Shyamalan's film Signs, the protagonist suffers a crisis of faith so deep that it takes an alien invasion of Earth for him to work it out. In Shyamalan's latest movie, The Happening, which opens today, the protagonist suffers a crisis of reason. Unfortunately, this time not even the looming extinction of humanity resolves it for him.

Given that it's mass entertainment, the film raises a lot of interesting questions about science, and it's clear from it that Shyamalan's interest in science goes much deeper than a superficial mining of ideas for plotlines. His protagonist, high school biology teacher Elliot Moore (played by Mark Wahlberg), lectures about the limits of science's ability to explain the world and applies his critical faculties to staying alive when the "happening" happens.

(Spoiler alert from here on!)

He deduces that trees and grasses, stressed by human presence, emit a toxic substance that causes progressively smaller clusters of people—first cities, then towns and villages, then groups of refugees, and finally lone individuals—to commit suicide. Meanwhile, his friend Julian (John Leguizamo), a math teacher, comes to terms with imminent death by teaching one last student the parable of rice grains on a chessboard.

To the wider world, it remains unclear whether the attack was a terrorist incident, a bioweapons experiment gone awry, a nuclear accident or another of the usual suspects, and the film ends with humanity still missing the environmentalist message—at its peril.

Scientific American's George Musser interviewed Shyamalan by phone earlier this week. Here's an abridged, edited transcript of the conversation, a version of which is also available as a podcast.

SHYAMALAN: Did you see in The New York Times yesterday about plants talking to each other? It was the front of the Science Times. I couldn't believe it!

MUSSER: Life imitates art, I guess! We also had an article a few years ago by Robert Sapolsky that talks about how parasites affect animals' behavior and effectively causes them to commit suicide. So that is also life imitating art. There's a quote in that article that ties into the zoo scene of the film: "This is akin to someone getting infected with a brain parasite that…generates an irresistible urge to go to the zoo, scale a fence and try to French-kiss [a] polar bear." There are these parasites in nature that subvert and turn the survival instinct against the animal. In this case, it affects rodents and takes away their fear of cats. It's the parasite that pregnant women are warned not to get near to litter boxes about.
Wow, that's fascinating.

One of the things I wanted to ask you about were your thoughts about the limits of science. That's clearly something on your mind; it comes out in the very beginning of the film and toward the end of the film as well.
The thing is, we have only our own invented categories in which to judge things. This thing that we're looking at, which of our eight categories (or however many) does it fit in? The things that don't quite fit in, we shove into something. We're inventing those categories; it's very limited. Psychologically, if you're looking for something in your data, you'll see it. If you're doing an experiment and you're looking for patterns, and you go: "Oh, there it is! I see it!" In that same way, if you're going, "There's always an explanation that we have already at our fingertips," you're going to find some way to put it in there.

But there's so much unexplained stuff. I don't quite understand the scientific explanation of the placebo effect. What is the core of that? The fact that the placebo effect exists is a fact, but what is it? We have no idea. I love that. I even love that with regard to the home-court advantage in sports. What is that? It's connected to a belief system. Both things, the placebo and the home-court effect, are a belief system that we can turn thought into actual biological function. In and of itself, that's something that science says is not possible. But you can document it.

It's interesting you say that. Most people, if you just stop them on the street, would say that science has always got the answers to things. But if you stop most scientists in their laboratories, they would say the exact opposite: how little they know about the world. Science as an act of humility. And I think you had Elliot say something very similar to that.

Do you see some of these "acts of nature"—in the film you brought up red tide and colony collapse—as forever beyond our capacity to explain? Or is it something that, with enough thought and enough effort, we can explain?
It'll either get thrown into some tentative, tenuous explanation or it'll be thrown into the pile of the placebo effect: "Okay, it's fact, but we have no idea." There's another one: When the tsunami came, the animals all ran, sensing it happening. What is it that's in their primitive—we'll call it "primitive"—biological makeup, that we've forgotten? It would seem that would be quite an asset for a species to have what they have—knowing something's wrong and we better get out of here. We don't have that, and yet we're supposed to be higher-functioning. So what happened? We don't even understand that. What is it about the intuitiveness of animals? Is it some microscopic shift in the atmosphere that they're sensing? What is it, exactly?

There's so many of those amazing things that tie us to each other, that make us all one system. I think the basic thing about the movie is that we're pretending we're not part of the system.

You said you had drawn inspiration from Einstein's recent biography, the Isaacson biography. What were some of the things you pulled out and tried to instill into what you did?
It's the same type of thing. I get that feeling of what drives you to say that there's an answer: the beauty of simplicity. What is the beauty of simplicity? That is, there's something that binds everything. To keep looking for that, that drive is almost the holy grail. I can totally relate to that on an intuitive level. That's somehow tied to some mystical thing—I don't know if "mystical" is the correct word. It's beyond logic; it's the evidence that all things come from one simple thing.

Fundamental physics, as Einstein practiced, is always at that boundary between physics and metaphysics, or the mystical and the material.
Yeah, what was that whole thing he was struggling with when he said that God doesn't roll the dice? It's random, where a thing is?

Yes, in quantum mechanics you've got that kind of irreducible randomness.
He doesn't like that—and I don't like that, either. At the end of the day, things can't be random.

That was Einstein's point of view. Some people wonder whether that was right or whether there is this randomness that we'll never be able to explain, that's inherent in the world.
That would be counter to, at least, our primitive understanding.

It's interesting what you say about the beauty of simplicity, because I think you had that embodied in the character of the math teacher. Facing an inevitable death as they drive through Princeton, he tries to bring that out in his fellow passengers in the car. Here they are, they're about to die, and to give their death some nobility they went back to a math problem: the beauty of simplicity.
Exactly. Just talking about how amazing that is, what we think of it as a small thing: the principle of doubling, which in a very short order makes an incredible magnitude. I told John when he was doing that scene that he sees beauty in those numbers and that he's always found this kind of awe at it. There's a great satisfaction that comes from understanding that you do this, this and this, and it comes out to that. It's amazing. It's the thing that's driven him and makes him connect with Elliot, who sees that in science. That's why they're so close. And then he's in that room and he just wants one thing: This is my joy, what I see, this is the joy of life for me. Just one more time, just teach one more kid that joy.

Obviously, a lot of people as they come away from the film, or as it will be depicted in the press, will talk about the environmental aspects. Clearly, the whole plot revolves around that. But I wanted to ask you from a deeper level—that there's this breakdown of the survival instinct. In the real world that we live in, there's also sometimes this breakdown of the survival instinct. We do things that are not in our own survival interests. There's the classic example of someone smoking in an organic food restaurant. There's also our attitudes toward risk, and that comes out in how the government is not approaching global warming, for example.
That's true. You could give mitigating factors for each of those. The survival instinct is somehow ingrained in us. Maybe there's a gut version of that and an intellectual version of that, and the intellectual version of it fails us all the time. So we smoke in an organic food restaurant. It just fails us.

A lot of our instincts have flipped. It's not like we're running out to go hunt deer down for the dinner; we have it readily available. So the body's instinct to store carbs is now turning against us, and so everybody's obese. But you can't turn it off. You can't go, "We're always going to have food, stop triggering that thing!" You just crave and crave. That's why everybody's kids are always, like, "How come we always want to eat the bad things? Why can't we want the vegetables, and not the carbs?" The body's doing that from an old, old habit of trying to store as much fat as possible.

When I was thinking about what could you do to the human species if you were fed up with it, it's a very basic thing of the survival instinct gets turned off.

There's this natural backlash against humanity in the film. Of course, in reality, there's always a type of a backlash. Life is much more precarious than we sometimes give it credit for. Civilization is more precarious. Was that also kicking around in your mind?
Right now, I'm on the highway in Manhattan, and there's a million of us, and it all seems very important, where we're going. There's some trees lining this road that we're on here, the West Side Highway. But really the moment that you feel accurate, with regard to our importance in the world, is when you're out in the ocean and you get a little too far out. You're floating out there and you get a little bit of a pang and then you look around and it's so far out. You thought you were in the same place, but the ocean has pulled you another 50 yards out. And you're out there, and you feel vulnerable.

Those are the tiniest moments in your life that you actually feel the correct relationship with nature, as when people are in a giant storm. At those moments, it is precarious. Those are the moments when we go back to the Native American point of view of nature: "Oh yeah, you remember those silly, simple folk? They're right!"

You mentioned in the press conference you had done research as you were writing the script and talked to people about the plausibility of the whole concept. Can you describe it a bit more?
It was about the plant mechanisms: how they react to threats, that they are proactive, and that they have evolved incredibly complex systems to deal with problems. A cotton field, when it's getting attacked by a parasite on one side, will send out a signal to the other side of the field to tell it in advance that it's getting attacked and should put out the chemical for predators. It's an amazing kind of communication system.

Also, could it be possible that everything is reacting? That would only work if they were all communicating. Is that possible? And it came back that it was the case.

One thing that really struck me also about the film is really the ending. Three months had passed, and it was almost as though life had gone back to normal. Was that because, in your conception of this, people had ignored that signal?
Yes, that there was enough ambiguity to let it go. As long as you give them an out to go back to their lives, they'll take the out. The path of least resistance. So if you tell me it's probably the government or it was a nuclear leak, if that was possible, I'm just going to go to that, and I'm going to keep it at that. To make a change [to our relationship with nature] on that scale that we would have to make if that was happening, I don't know if we would be capable.

What kind of changes do you think it would entail, at least within the fictional universe?
It would mean a complete eradication of what it is that large populations do, how they're affecting the environment. Is there a collective energy we're giving off? Why do plants grow when you sing to them? All those kinds of questions. Do you give off an energy? Is "energy" even a valid way of communicating this idea—not a New Agey thing, but a real thing?

So it would provoke some kind of introspection about those kinds of effects that we're having on nature?
You start to get back to the correct hierarchy about thinking about our relationship with nature—again, the Native American thing, which I think is the correct one.

What role do you think that science would play in the transformation that would occur?
It would come down to the same type of things we're talking about now: cut emissions, and things like that. What are we allowed? Is it right to have four million cars on this road right now, rather than public transportation?

But ultimately you would be optimistic that we could work it through, just if we had the will to do so?
Someone was telling me recently about farms where they're self-sustaining—this fancy new idea of self-sustaining. I was like, "You mean, like the way we used to be?" You grow what you can eat, and what's extra you give to the community—you do that, not more than that. If we went back to that a little bit, we'd get back into harmony. They don't mind us being here, as long as we're not taking advantage of the situation.

But you think we could sustain an industrial, modern civilization, or we'd have to go back to a simpler—more rural thing?
That's a good question. We'd have to rethink everything. Can you create an organic plastic? Can you make something that can go back to nature? If not, then we can't build that thing.

These are in microcosm issues that our whole planet will be facing in the next 50 years or so.
Exactly. Every single thing, every single choice will be evaluated through the matrix of how is it affecting the group.

Do you think you'll explore those same ideas in future films?
I don't know about those same exact ideas, but definitely, the science is such a fun kickoff point for larger issues. It does have that based-on-a-true-story feeling to it. You can really take it one more step and just take it to a nightmare situation and then wake everybody up. I definitely have a couple things noodling around in my head now.