Return to the audio for How to Science episode 10, with developmental psychologist Henry Wellman.


Henry Wellman: I don’t think it’s so much that kids are little scientists—I think it’s that scientists are big kids.

It’s a natural human activity to explore, to try to understand, and that’s a natural human activity, because that’s what we’re like as kids. That’s how we become scientists.

I’m a developmental psychologist. Kids grow up to be adults, and part of what I wanna understand in all of this is how we become who we are. And who are we? Because who we are is partly defined by ourselves as kids and how we got there. We’re the products of our developmental history. We’re a species that has a really, really long period of immaturity in which to develop in protected juvenility. I think that part of that is because we’re a species that really privileges learning.

I’m Henry Wellman, and I’m a professor in the Department of Psychology. I’ve been here at Michigan for 40 years. For all those 40 years, I’ve been interested in sort of the same question. It is: How do children think?

After I graduated from college, for a couple years as a kindergarten and preschool teacher, I was in a preschool classroom with four-year-olds. I was helping this four-year-old put his shoes on, and I said one of those things that adults often say. I said, “Oh wow, your mom is gonna have to get you some new shoes soon, because you’re getting so big.”

And then that child sort of paused and looked at me and said, “No, your feet don’t get any bigger.”

And I said, “Huh, how does that go?” 

And he said, “Well, you drink your milk, and it comes out in your pee, and it never reaches your feet.”

And this I thought was great for two reasons. First, it showed that children and adults don’t think alike. But more importantly, it shows that children aren’t just ignorant—they’re not just empty of ideas. They have their own ideas. They think differently. Their thoughts are oftentimes revealing of internal theories they have about how the world works in certain sorts of ways. In this case, how nutrition biology works: You eat stuff, it goes inside you, it gets transformed into certain ways, it gives you growth, it gives you energy, and stuff like that. And that was a very sensible—after I asked a few more questions, a pretty sensible set of answers that this kid had, and they were coherent in certain kinds of ways, and that fascinated me.

Why are kids thinking like this? What are they thinking? How does that change with age? How does that develop? We’ve done studies on that. Children form naive theories about biology—naïve biology. But also about physics: the world of objects and forces and how they work. And also naïve psychology: How do people work? And why do they do what they do and say what they say?

So for a lot of our research, we bring kids into the lab, set up experiments to try to help reveal their thoughts, set up provocative kinds of things so that they might be intrigued to talk about them. We do this with even babies. So in my laboratory over in the psychology department, we do things with kids as young as six months old, and then all the way up to one-, two-, three-, four-, five-year-olds. And as I said, understanding about people’s insides—their minds.

Mostly with babies, we shoot videotape that shows people acting in either ordinary or non-ordinary ways. One of the things we know about babies is: Everything else being equal, if you set the situation up right, they like to look at the odd stuff. They like to look at the novel stuff, not the old and familiar stuff, so we record how they look at things. Children understand that people are different than objects in lots of different ways. They can engage actions on their own, spontaneously in ways that like a rock can’t. For a rock to move, it has to be moved. But people actually are objects, too. They are physical objects.

So in this particular study, the videotape is this woman walking across a big raised platform. And in the ordinary case, to begin with, she walks across it, and she knocks on it. So it’s clear that it’s solid. And she knocks on the side of it—the fall-off, the cliff part of the end of this big platform—so it’s clear that’s solid, too. And her fist goes right through the air, so it’s clear that’s just air there. So after that setup, the woman walks to the end of the platform. Stops.

Pretty routine, pretty ordinary—if you understand things like gravity and solidity and support, and that people are objects like that.

And then in the extraordinary event—the unusual event—she walks the the end of the platform and just keeps walking straight off and floats in the air. We just filmed this with a green screen.

Oh, babies think that’s really weird! So they watch that one a lot, and a lot more than the other ones, and they’ll watch that one a lot more than the one where she walks off to the end and then steps down. So, babies understand that people are special—they’re not just ordinary physical kinds of objects. They are propelled by different forces—forces inside them, forces like their desires and their beliefs and things like that. But that’s not to say that they’re not objects. They can’t defy gravity just like any other object can’t defy gravity. 

So one of the things we have now is a series of studies on children and robots.

Those robots can kind of look like people. They can act on their own, too. Do they have minds? What do kids think about that as minds? What do kids think about that as a material device—a machine, not human, but they may have a mind? How does that either stretch or reveal what they think about?

I talked about it at the very beginning as children forming theories, and I think that’s exactly what they’re doing. They’ll surprise you, but they’re smart. Or, they’re a combination—they’re both sort of wise and witless at the same time. Figuring that out is the fascination.

All kids are surprising. 

Monica Dus: I don’t have kids. I typically think of kids as people who will get me sick or get my silk dress dirty. But thinking of science in society—you were a scientist in society when you were a preschool teacher. You literally started studying society. You got a set of insights that people like me would never think of, would never cross our minds. Clearly, that shaped you pretty profoundly. But what things about you do you think set you apart from people that didn’t have the experience of being in society with four-year-old kids?

HW: I think pretty much of all good science depends on the scientists steeping themselves in their subject matter in ways that aren’t just programmatic, like “Oh, I want to understand about this, so I’m gonna look at this one thing.” But keeping your eyes open and understanding how these phenomena work, or how they appear and manifest in a wide variety of situations, not just in the lab.

I think I was lucky, but it also fueled my scientific fire, in that I had all those experiences to begin with that led to the science. I think those two things have to be melded together.

And that’s important for scientists’ work, especially if you’re gonna continue being fascinated and open up new things over 40 years.

To bridge those two sorts of things, you can’t just stay in the lab. You have to have these other sorts of experiences and try to connect them together. So, I would think that would be true for any kind of science. Science and society will manifest itself in different kinds of ways. But it’s pretty easy with kids, because there they are—they’re part of society. They’re out there. They’re everywhere.

Sit next to a kid on an airplane sometime and talk to that person. Not the squeaking baby—sit next to a four-year-old sometime. You might get fascinated. 

When you started your lab, was that an unusual thing to think about—that kids had their own minds and theories and scientific view of the world? Was that a controversial position?

HW: Yes and no.

Educators oftentimes have some pedagogical kinds of ideas which are: “Well, kids just need to be told. They just need to be instructed. They are just empty and ignorant, so we just need to give them the right kinds of ideas.”

Now, it turns out that that’s not very true. At least at the time, and even now, more with people who are interested in early childhood education—kindergarten and pre-school teachers—they thought that kids did have their own ideas, and they did their own things like play, and you don’t have to teach them this kind of stuff. You have to encourage them to explore the world with play, because they will come to these sorts of ideas somewhat on their own.

But still, in American psychology, the largest sort of thrust at the time that I was a graduate student—this was back in the ‘70s—was more the kind of way you were talking about. Thinking about kids as ignorant, and instruct them, and stuff like that. But I think scientists are supposed to certainly base our theories in observations, but we also have to do more than observe. We have to theorize, we have to experiment, we have to test, we have to formulate our observations in such a way that they make sense. Sometimes, just like kids, our formulations are gonna be wrong. We’re gonna test them against the evidence; we want to revise them; we want to be open to all that kind of stuff. But observation is really important. 

We often think of scientists as doing these aspects, all the work of science in the lab. But in fact—at least in your case—there is a very specific example of the very first step of the scientific method actually occurring in society. Hearing about that, I find that really compelling.

The other thing that I find really compelling about the stories you describe is that, in many ways, your research is studying the development of society.

HW: My story about kids as scientists and engaging in theory means that they’re creating some of this on their own. They’re not just absorbing it.

The end product—what kids are like as adults—doesn’t mean that they've just bought into the standard story. Some kids become rebels; some kids become scientists; some kids say, “Hey, I don’t believe that. I’m gonna go off and try to do this other thing, instead.” Sometimes, some of the biggest propellants of societal changes are young people. And that’s because they have some protected spaces that do that. They come to the university and explore new ideas and things like that. But sometimes they’re just trying to figure it out. And sometimes they’re also embarked on a path of trying to get society to change for the better, as they see better.

There’s a thing called “adolescent utopianism”: “I’m gonna create a better world! I got these ideas. That flawed society’s not great. I’m gonna make it better.”