One in four people thinks the sun revolves around the Earth and not the other way around. Four in ten Americans reject Darwin’s theory of evolution. And even some Harvard graduates believe the reason winter is colder than summer is that the Earth has moved away from the sun.
People lamenting the pervasiveness of these and other basic scientific misunderstandings often point to poor education, or blame religion or politics. But as psychologist Andrew Shtulman argues in his new book, Scienceblind: Why Our Intuitive Theories About the World Are So Often Wrong, these kinds of mistakes frequently stem from deeply held ideas that we all form in childhood, and carry with us into adulthood.
Children naturally create intuitive theories about how the world works, based on their innate knowledge and their observations of the world, Shtulman says. These ideas are not only often wrong — they’re also hard to shake, persisting after high school and even college-level science classes. Our childish intuitions continue to guide our decisions — you can see this in the grocery store, for example, when people choose to buy raw milk or shun genetically modified foods. But even more importantly, these gut instincts can have a big effect on political debates about broader issues like climate change and vaccination, too.
In an interview with Science of Us shortly after the March for Science, Shtulman spoke about science denial and why teaching critical thinking isn’t enough.
I saw recently that there are apparently now four NBA players who claim that the Earth is flat. Kyrie Irving was quoted as saying, “If someone didn’t teach you [that] you were spinning on a ball orbiting the sun, is that what you observe with your five senses?” It seems like this really exemplifies the kind of intuitive — and wrong — theories that your book is about.
Definitely. We would never, any of us, think that we are on rotating, orbiting sphere, if we hadn’t been taught. It took humans hundreds of years to discover that fact and it remains counterintuitive to every child who learns it.
So why do we get the world wrong so often? Is it just like Kyrie Irving says, that the scientific realities of the world are beyond the grasp of our day-to-day experience?
We’re not set up to perceive the world as it actually works. We’re set up to perceive the world in ways that help us function in daily life. There’s at least three sources of information that feed into the theories that we construct about the world. There’s innate knowledge — so there’s some concepts that humans appear to be born with. Like, we have expectations about how objects will behave and interact with one another.
Another source is experience — firsthand observation of the world and interaction with the world. We’re not going to ever perceive the Earth as a sphere, we’re going to perceive it as flat, because the ground is flat, and we’re going to perceive gravity as a force that pulls things down as opposed to a force that pulls things toward the center of mass.
And then the third source of information is culture — culturally constructed knowledge that’s transmitted from one generation to the next. Because everyone in the culture is predisposed to develop intuitive theories, sometimes those get worked up into a fully articulated set of beliefs. Religion is a great example: A lot of religious ideas about the natural world are sort of extensions of intuitive theories.
What’s at stake here? Getting basic facts about the world wrong doesn’t just mean we fail science tests, right? You talk in the book about the moral consequences of scientific reasoning.
In the last chapter I mentioned about how someone who was lecturing on intuitive theories and moral reasoning made the point that intuitive theories are not as important as moral reasoning, because moral reasoning is how we interact with people in the moment. And that point made me bristle, because intuitive theories matter, too.
We base our decisions on what policies to enforce and what actions to take in a given situation based on how we understand how the world works. There are plenty of issues in politics today where people disagree about the underlying causal structure of some set of events and so they think that we should take very different actions. Climate change is a great example — vaccinations, genetically modified foods, pasteurization of foods. If you have different ways of understanding what it means to genetically modify an organism or what a vaccine is doing in the body, then that’s going to lead you to endorse different policies and take different actions, so I think they’re just as consequential.
But are some wrongheaded theories more consequential than others? It seems like if someone thinks the Flintstones got it right and humans and dinosaurs walked the Earth together, that’s less dangerous than if someone thinks vaccinations are a hoax, right?
It’s hard to know what’s going to matter. I’ve been interested in these issues for 15 years, and when I was an undergraduate in college I did my thesis on how people understand evolution, as opposed to how evolution actually works. And everybody would just scratch their heads when they heard me describe what I was doing. They were like, “You’re showing people that people don’t understand evolution? Why does that matter?”
But it’s become very evident in recent years why that matters — because there are fights about whether or not children should even be exposed to evolution in schools. There are fights about public-health issues that relate to evolution: the overuse of antibiotics, the use of pesticides, how to deal with non-native species, how to even think about that issue.
On the one hand, you could say evolution is one of the more peripheral issues: Your understanding of evolution is not directly related to your decision of whether or not to vaccinate your child. But on the other hand, it has these widespread consequences, where if you really dig down and get to the root of why people are confused, part of it is they just don’t understand evolution and biological systems and how they’re related and how they change over time.
It seems like a trivial misconception that people think that humans and dinosaurs coexisted. But in order to hold that misconception, you have to have a really truncated view of time, not understand how many millions of years passed between the extinction of dinosaurs and the emergence of humans. And all of these things are tied to larger issues about how you think about geological systems, biological systems. So I wouldn’t want to say, here’s a set of misconceptions that would be nice to fix but they’re not really that important. Because I think they’re symptoms of a larger set of problems.
Education seems like the answer here, but in the book you say that teaching critical thinking is not enough to uproot mistaken theories about the world — that instructors really need carefully targeted lesson plans.
I like the way that you put that: Critical thinking isn’t enough. Because I don’t want to suggest it’s not important. It’s just different. You’re not going to figure out what people mean when they say that the Earth is round — meaning that the Earth is a sphere — just by learning how to analyze texts for evidence or just by being able to design an experiment where you control one variable at a time. Those are important skills, but they’re not content-specific.
We’ve carved up the world into a set of categories, a set of processes that in many cases just don’t exist. There are certain concepts that you hold, and that concept just doesn’t map onto anything in reality. Physics is a great example. When people try to explain why objects move, they think it’s because a force has been imparted to an object and that force keeps the object in motion after it’s left the hands of the mover or whatever set it in motion. And that force dissipates over time or is overcome by gravity and that’s why the object eventually comes to rest. This force went by the name impetus in the history of science, and people really thought it existed and they tried to measure the properties of impetus and how impetus interacted with gravity and friction. But there is no impetus. So you’re not going to get very far with that theory. You have to abandon that idea before you can start learning about inertia and the relationship between force and acceleration.
So what is needed, in terms of education?
The most important thing is just for educators to point out the existence of intuitive theories. You devise activities that get students to articulate their intuitive theories. You set up some situation where you have them make predictions, predictions that you know are going to be based on intuition, and you know are going to be wrong. And then you show them that they’re wrong and then you get them to see the difference between their way of reasoning about the problem and the way that scientists reason about the problem, to try to highlight those discrepancies.
And that needs to happen discipline by discipline?
Oh, definitely. The physics teacher can point out that this is the way that you intuitively think about parabolic motion but it’s wrong — this is the way you should be thinking about it. And that’s not going to transfer to thinking about genetics, or thinking about evolution. That’s got to be a different set of instructions that makes those connections or points out those discrepancies.
Is there a bigger challenge right now, that people see science as just another belief system, and a dubious one at that?
I don’t think that that’s a new objection. I think it’s just one that’s more often voiced nowadays. Like it’s not politically incorrect to be very vocal about that objection. Science denial is in vogue right now. But scientists are pushing back.
There’s always going to be a core who think science is counterintuitive — because it is — and have alternative ways of explaining the world and want their children to know those alternatives. But I think there’s a larger group of people who can kind of be pushed one way or the other depending on the political climate or the sociological climate.
On the one hand, this seems to be a moment when science is under attack. But on the other hand, as you point out in the book, elementary-school children now learn what were once very advanced scientific theories. So how are we doing overall?
I think it’s easy to think that we’re in a dark moment when you see Trump sign an executive order that reverses climate-friendly policies. But on the other hand you’re right to point out that there’s been a huge amount of progress sort of under the radar — that children are being taught all these things that were at the forefront of scientific inquiry 50 years ago, and now it’s just a standard part of their curriculum.
Germs and genes are great examples. We’ve only known about germs for, I think, 150 years and now every little child knows the word germs. They don’t understand what germs are initially, but it functions as a placeholder. They know there’s something that’s invisible that causes you to get sick and then you figure out that that thing is actually a living creature, a biological agent that invades your body and reproduces.
Genes, we’ve only know about those for 60, 70 years, and now that’s a standard part of high-school biology, to understand not just that they exist but the fine biochemical details that go into copying genes and the translation between genes and traits. So that’s got to make a difference in how future generations think about science. The average educated person will just know a whole lot more than the average educated person did a generation ago.
Are you concerned that the people who might need your book the most won’t read it, or that the people who are drawn to it will be the people who are already interested in science?
No, I think that’s fine because I think it will possibly give these folks who are interested in science a new way of understanding why the members of their family deny science or why they read news articles that misrepresent science. I think we have a tendency to think that there’s like an active motivation to reject science. Like basketball players who claim the Earth is flat — we think, Well, they must be really stupid or they must have some reason for doing this. And what I try to argue is that actually, no — we’re all predisposed to be confused about science and think the Earth is flat. It’s actually a hard-won developmental achievement to understand science and to accept science as a better explanation for how the world works than your own intuition.
Maybe someone will get a copy of your book to Kyrie Irving.
I don’t hold out any hope that he’ll read it. But, maybe some other people near him will gain some appreciation for why he says what he says.