How do children grasp science reasoning?
We've heard a lot about how memory is involved in learning, but when we're learning things like science, you need more than just memory. You need understanding. So how does this develop? Sara Baker is based at Cambridge University and spoke with Ginny Smith...
Sara - Well, that is a big question. There are indeed a lot of things involved in learning about science. There's learning certain facts and how those things work, but science itself is more of a process really, isn't it? So, it's about thinking about what's in front of you, reasoning about all of these different things, putting together the pieces of evidence, and then drawing conclusions about what kinds of theories might be true of the world. So, there's lots of different levels at which people need to be operating when they're trying to do science.
What we know about even very young children, as young as say, 3 is that, it comes quite naturally to people to reason in a scientific way to test out different things and then see what happens and maybe adapt what they think according to what they've observed.
Ginny - Now, I've seen babies sitting on a high chair and systematically dropping things over the side and sort of watching where they're going. Is that what we think they're doing when they're doing that or are they just making a mess?
Sara - It's true that even infants before they're talking are already experimenting with the world a little bit. What we think, those of us who do research in this area, is that children may even be born with theories of how things work. Gravity is one of those things. So, objects that just drop straight down when they're not supported seems to be a theory that children have from very, very young. They're not taught that. They just have this theory and then they have to actually sometimes learn to adapt that according to the circumstances. So, a lot of science may be about unlearning things that you think are true.
Ginny - So, how do you go about trying to find out what these kind of beliefs that children have are?
Sara - Well, we do very simple things. So, it might involve for instance, putting some object on a shelf and then asking people to predict what's going to happen when we drop them off of the shelf, and if you vary say, the weight of the two objects and ask people, will they fall at the same speed or different speeds, which one will land first, will it be a draw. Just very simple things like that where you get people to make predictions and that's exactly what scientists are doing all the time. they're observing a phenomenon, making a prediction about what will happen and then collecting the information and seeing whether that was confirmed or not.
Ginny - You were talking earlier about how there are differences between different people and how they think and different children, how they learn. What kind of differences do you see when it comes to scientific reasoning?
Sara - We did one study where we were looking at how children in pre-school - so between the ages of 3 and 5 - learn about gravity and inertia, very basic principles of object motion. And in this particular study, we let an object (so a ball) roll down a ramp and then they had to say where this ball would go when it came to the edge of this ramp and would it fall straight down or go forward and down or what would happen. What we found was that the younger children had very fixed ideas about what should happen and when that's not what happened, they just didn't know what to do anymore. Whereas older children may have had a fixed idea at first, but once they got the evidence, they said, "Oh yeah, okay. So that's actually what's going to happen." So, they were using the evidence much more readily than the very young children.
Ginny - What kind of ages are we talking here?
Sara - So, the 3-year-olds in fact, when we showed them this event, that was not what they expected. Several of them just went, "What? Again?" You know, you can do this repeatedly and they still just don't take it on board whereas a 4-year-old or a 5-year-old, you may disprove their belief in the first go, and then they just immediately kind of adapt to that and say, "Okay, right. So this is what's happening now."
Ginny - So, we sort of learn that we have to change our beliefs as we get older? Is this something that you can apply in the classroom and the teaching of science?
Sara - Yes, hopefully. I mean, our hope would be that a lot of this research could be used in science classrooms. I think it's really important that in the classroom, kids have the opportunity to experiment with things and test them out. Not just have one go at it, but probably, several tries because I think that's where we see really interesting things, it's after lots of exploration.
Ginny - Kate, did you have any questions from social media?
Kate - Anthony asked us on Facebook, "Are children more receptive to habit forming when they're young?" He wants to know, "If I start my 6-year-old making her bed now, will it stick?"
Sara - Actually, I just want to tell you, this is not a scientific fact, but it's an anecdote from our neighbour who told me this the other day. The first time he took his 18-month old and walked to school with the older child, they sat on the bench that day and had an ice cream. So now, every time they walked to school, his little son who's 18 months wants to sit down on the bench and have an ice cream. So, he's formed his habit in one go which is not necessarily very convenient for the school run. But I think there are some things that kids will learn scripts like that, daily routines very quickly. And that's probably a good thing because if they're meant to learn so much in such a short time, they're endowed with this brain that can do that. But on the other hand, something like chemistry, you may have to hear it 10 times before you'll ever even understand it. So, I think it's really going to depend, but you know, you can try it with a bed making. That's a great idea.
Kate - So, you're saying, all the parents should make their kids make their beds for the next week to see what happens.
Ginny - Have we got any questions from anyone else? Dave has got one.
Dave - I'm Dave. Do you find that everyone comes up with the same models in the universe in their heads or do different people have different models and does that affect them later on?
Sara - Right. That's an interesting question. I think it certainly does depend. I mean, I've done studies where we compare how pre-schoolers think about a given thing and we show the same thing to all the kids. They'll learn about it at different rates and they'll come up with different theories to explain what's happening. That's true. There are other things which seem to be more or less universal. So for instance, if you ask young children to draw the world and to put people on it, they'll draw the people standing on the top which is quite interesting, isn't it? If we think back to what we know about gravity and how that's complying, of course, they should be on the top. So, there are universals like that and then other things where people make up their own ideas.
Ginny - Now, I don't think we can keep Hannah's volunteer waiting over there with her electrodes on her head any longer. Are you going to tell us what you're doing to this poor young lady?
Hannah - So, we've got Maddie rigged up some electrodes here. How are you doing Maddie? How are you feeling?
Maddie - Fine.
Hannah - Fine. She says very timidly. What we've got here is Maddie's brain waves. So, we're reading the electrical activity in Maddie's brain. There are about a hundred billion nerve cells in Maddie's brain and they communicate with each other using electricity. A little bit like the electricity that turns on a light. This electricity that allows Maddie to have an understanding of the world around her and process all the information that's coming in through her senses like her eyes and her ears.
Kate - I can't see lots of neurons. I can see a blue line and a wiggly green line. What do those mean?
Hannah - So, the Y-axis is the part of the graph that goes up towards the sky and that's the potential difference or voltage of Maddie's brain. On the X-axis, it's time in milliseconds and there's lots of squiggly lines. The blue graph is something called Maddie's beta waves. So, it's a particular frequency of electrical activity. Maddie, what I going to ask you to do is stay still as possible.
Kate - There were lots of spikes on the blue one, but they're sort of dampening down. They're getting smaller. Does that mean Maddie is thinking less?
Hannah - It does. It means that she's thinking less. Maddie, I'm now going to ask you to move your head repeatedly.
Kate - We can see lots of spikes as Maddie moves her head. What's the difference between the beta waves on the top and the green bit on the bottom? Do they show anything in particular? Is one happy or...?
Hannah - So, the beta waves increase in the amount of spikes that they have when Maddie is concentrating or focusing on a particular task. So, when I just asked Maddie to move her head, there was a part of her brain that was concentrating and focusing using lots of electrical activity in order to get her to move the muscles in her neck. And we're also picking up the electrical activity of Maddie's neck muscles as well. So, background noise. I'm now asking Maddie to just stay as calm as possible and not concentrate on anything at all. Instead, pretend that she's on holiday, relaxing with her best friend. And we're now seeing a spike in the green graph. There was a small spike there. Now, the green graph is associated with o relaxed thinking. And so, we're seeing a change in activity there.
Kate - Can we have a big round of applause for Maddie and her beautiful brain waves?
Hannah - So, this is another way that scientists look at the brains of children and also babies to find out how they learn things and how they remember things. Scientists are trying to see if they can use many more electrodes than three electrodes that we've got on Maddie's brain here to try and find out if you can diagnose babies that might have for example autism or maybe they're predisposed to having Schizophrenia or attention deficit hyperactivity disorder, or even dyslexia later on in life by using this type of analysis of electrical activity. I have to say that Maddie's brain waves are beautiful.