Everybody’s abuzz about the article by Paul Bloom and Deena Skolnick Weisberg (the link goes to a reprint at Edge.org; you can find an illicit PDF of the Science article if you poke around a little) about research into why people don’t automatically believe scientific explanations. From the article:
The main source of resistance to scientific ideas concerns what children know prior to their exposure to science. The last several decades of developmental psychology has made it abundantly clear that humans do not start off as “blank slates.” Rather, even one year-olds possess a rich understanding of both the physical world (a “naïve physics”) and the social world (a “naïve psychology”). Babies know that objects are solid, that they persist over time even when they are out of sight, that they fall to the ground if unsupported, and that they do not move unless acted upon. They also understand that people move autonomously in response to social and physical events, that they act and react in accord with their goals, and that they respond with appropriate emotions to different situations.
These intuitions give children a head start when it comes to understanding and learning about objects and people. But these intuitions also sometimes clash with scientific discoveries about the nature of the world, making certain scientific facts difficult to learn. As Susan Carey once put it, the problem with teaching science to children is “not what the student lacks, but what the student has, namely alternative conceptual frameworks for understanding the phenomena covered by the theories we are trying to teach.”
This has created a lot of discussion, as if it’s new and surprising information, but honestly, as a person working in physics education, my reaction is pretty much “Yes, and…?”
This is old news in physics– the article even cites a study that found large numbers of people opting for an Aristotelian picture of motion in which rolling balls leaving a curved pipe continue to travel in a curved path. The study in question is from 1980, which is probably before some of the people commenting excitedly about the new article were even born.
The new twist here is that they apply this argument to politically charged topics like evolution. But really, if people have a hard time shaking preconceptions about physics that can be proven false with about two seconds’ worth of experimentation, why is it surprising that they don’t immediately accept biological processes that take place over generations?
This does, however, remind me of something that always bothers me about these discussions, which is that they tend to be loaded with assertions that the basic rules of physics are somehow utterly alien to everyday experience. I’ll buy that for quantum mechanics, but I just don’t think it’s true for classical physics.
I often think that the problem with a lot of these conceptual issues in physics is not with the concepts themselves, but in the transition between the physical situation and the printed page. As the article notes, people actually have a pretty good innate understanding of the basics of classical physics– you couldn’t function, otherwise. The issue, it often seems to me, is not in the concepts themselves, but in the abstraction necessary to translate the real physical situation into an answer to a test question.
To take another classic example from physics pedagogy, consider the picture at right. This is another classic question, in which students are asked to choose the correct path followed by a projectile fired horizontally off a table. The correct answer is “B,” but a fair number of students will go for “D,” which is basically the Wile E. Coyote option: it hangs in the air for a while, and then drops very suddenly.
If you really believed that the world worked that way, though, you’d never be able to catch a baseball in the real world. Most of the students who miss that question have no problem predicting the motion of real projectiles, though– if you throw something at them, they can catch it, or at least make a credible effort to catch it. It’s not that their intuition about how the world works is wrong, it’s that they don’t do a good job of making the transition from intuition to conscious thought. When they track a real projectile, they’re not thinking “This will follow a parabolic trajectory due to the constant acceleration of gravity…” They just track it, and catch it. The problem comes when they have to think back about what they did.
It’s sort of like those spatial relationship tests where they show you an odd shape of connected squares, and ask what sort of three-dimensional figure it will fold up into. Lots of people score very badly on those tests, but it’s a rare individual whose spatial skills are so bad that they couldn’t fold the actual figure up into the shape in question. The problem isn’t with the physical process, it’s with the abstraction of that process.
I often think that the process of teaching introductory mechanics isn’t really about breaking down incorrect intuitions (as is often said) but rather about bringing conscious mental processes into better alignment with existing physical intuition. Students pick the Wile E. Coyote option not because intuition tells them that’s how the world really works, but because intuition means that they haven’t had to observe the real world all that carefully, and are basically guessing based on vague recall of falling objects. They’re overthinking the problem, not over-reliant on flawed intuition.
Other times, I think that I can’t possibly be right about that, given the large number of smart people who have made careers out of studying this stuff…
I’m not sure how you’d really go about testing this, though. It would probably have to involve some sort of real physical mock-ups of the classic conceptual questions– giving people coiled hoses, and asking them to align the hose to direct water at a target, and that sort of thing. It might be fun, but it’d probably get messy, too. Especially if I’m actually wrong.