Wednesday, May 30, 2007

Why we're sometimes thick skulled

In the May 18, 2007 issue of Science, Paul Bloom and Deena Skolnick Weisberg write a short review about why adults sometimes have trouble accepting claims made by scientists. Specifically, they apply findings from developmental psychology to explain the resistance to scientific claims based on two lines of research dealing with “what they [children] know and …how they learn.”

The first line of research has uncovered naïve conceptions that children have about the world. These are things that come pre-wired (if I understand things correctly). Bloom and Weisberg write:

"These intuitions give children a head start when it comes to understanding and learning about objects and people. However, they also sometimes clash with scientific discoveries about the nature of the world, making certain scientific facts difficult to learn.

This sort of thing comes up a lot regarding the teaching of science – the notion that before you can teach certain topics, you have to understand and deal with the preconceptions that students have about things. If you don’t, students might learn the material as you present it (and they may even give the correct answers on an exam), but if you ask them two weeks later, they will revert to their preconceived idea about the concept. In a video called “A Private Universe,” somebody went around asking Harvard graduates (immediately after commencement, I think) questions about science. One question had to do with where the matter to make plant tissue (wood) came from. Almost all the students said it came from the soil. Actually, it comes from CO2 in the air. (Makes you wonder about all those student loans you took out to pay the Ivy League tuition, huh? D’oh!) The point is that these students had a preconception, sat through some biology classes that taught something different, and came away without learning anything because the preconception wasn’t dealt with.

Bloom and Weisberg also note that children have a natural inclination to see things “in terms of design and purpose.” They continue:

“For instance, 4-year-olds insist that everything has a purpose, including lions (to go in the zoo) and clouds (for raining), a propensity called promiscuous teleology(15).”

David Gilbert, a Psychology professor at Harvard, wrote a nice little essay at Edge called “The Vagaries of Religious Experience” that dealt with this same sort of thing. (Not promiscuous teleology per se, but how our minds interpret certain events. I’d summarize his ideas, but you’re much better off reading his short essay.)

I wonder how much of this goes back to our ability to see cause and effect? We see what we consider an effect – the universe – and just naturally insert the cause – a bearded guy with grey hair that lives in space.

The second part of Bloom and Weisberg’s article deals with how we learn things. If someone makes a particular claim of truth, how do we deal with it?

“When faced with this kind of asserted information, one can occasionally evaluate its truth directly. But in some domains, including much of science, direct evaluation is difficult or impossible. Few of us are qualified to assess claims about the merits of string theory, the role of mercury in the etiology of autism, or the existence of repressed memories. So rather than evaluating the asserted claim itself, we instead evaluate the claims source. If the source is deemed trustworthy, people will believe the claim, often without really understanding it.”

Richard Dawkins wrote an essay published in his book “The Devil’s Chaplain” that addressed the difference in accepting a scientific claim vs. a religious claim, for example. How are the two different? Why is one appropriate (at least sometimes) and the other an indefensible appeal to received wisdom? Dawkins points out that although you, personally, may not independently verify a given scientific claim, it is possible to verify it. A scientific claim is public and open to criticism from anyone who wants to put in the time to verify it. Not so with a pronouncement by the Pope. Born of a virgin? If you say so.

Bloom and Weisberg conclude:

“These developmental data suggest that resistance to science will arise in children when scientific claims clash with early emerging, intuitive expectations. This resistance will persist through adulthood if the scientific claims are contested within a society, and it will be especially strong if there is a nonscientific alternative that is rooted in common sense and championed by people who are thought of as reliable and trustworthy.”

What we need to do now is learn how to break this resistance. Most of the education literature I’ve read suggests that you need to induce “cognitive conflict” in the students. They have to come face to face with the inadequacy of their preconception, then be shown how another explanation is better suited to explaining reality. Unfortunately, this is just very hard to orchestrate, especially with pressures to “cover the material.” And for some people, it's likely true that the only way to replace an emotionally held belief is with another emotionally held belief.

Note: a link to a pdf of the Science article is available online at Adventures in Ethics and Science. A modified version of the paper is available online here. PZ Meyers at Pharyngula also blogs about this article.

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