There is no polite way to say this: people who resist scientific explanations for natural phenomena such as the age of the earth and the fact of evolution are guilty of childish thinking.
So argue two experts in cognitive and developmental psychology, the science of how thinking and other mental functions change as people grow up. “Resistance to certain scientific ideas,” Paul Bloom and Deena Skolnick Weisberg of Yale University argue in the May 18 issue of the journal Science, is largely a result of patterns of thinking that are characteristic of young children but which, in some people, “persist into adulthood.”
Scientists bemoan the huge numbers (42 percent, in a 2005 poll) of Americans—and this does seem to be more an American phenomenon than a European or east Asian one—who believe that humans and all other animals have existed in their current form since their first appearance on Earth, despite fossil and genetic evidence showing that, to the contrary, species change over time in the process of evolution. Tens of millions believe—again, contrary to scientific evidence—that unproved medical therapies work, that out-of-body experiences are real (rather than results of particular brain activity), and that astrology has merit, for instance. But if you look at what children think and how they learn, the resistance to science and the persistence of unscientific thinking doesn’t look so surprising.
We come into the world with preconceived ideas about how that world works; like a computer, we’re pre-loaded with some programs and knowledge. Babies know that objects fall unless held up, for instance (scientists test for this knowledge by noting what surprises babies, and an object defying the law of gravity definitely does). Little kids know that people act according to goals. They believe that actions and situations have purposes.
Both pieces of knowledge give kids a head start in learning—but can clash with scientific fact. Children resist the idea that earth is a sphere, for instance, insisting that if that were so then people “on the other side” would fall off into space because of the unsupported-objects rule. (To reconcile this belief with textbook claims that the world is round, kids typically conclude that people don’t live on “the other side,” or else live inside the hollow sphere.) Kids’ belief that everything has a purpose leads them to conclude that the “purpose” of lions is to live in zoos, and the “purpose” of clouds is to produce rain, as a 1999 study in the journal Cognition found.
“Just as children’s intuitions about the physical world make it difficult for them to accept that Earth is a sphere, their psychological intuitions about agency and design make it difficult for them to accept the processes of evolution,” Bloom and Weisberg write. “The main reason why people resist certain scientific findings,” they continue, “is that many of these findings are unnatural and unintuitive.”
As you’ve probably noticed, even the most diehard creationist does not deny the existence of, say, germs or electricity, even though both are invisible and must be taken on faith. But information like this is common knowledge, not associated with a particular source. It cannot be evaluated directly (you can’t tell empirically that electricity is the result of moving electrons rather than, say, microscopic elves that zips through wires and turn on lights and TVs). When a claim is neither common knowledge nor testable directly, kids’ natural instinct is to assess the validity of a claim by the trustworthiness of its source. If an adult tells them the meaning of an obscure word, for instance, and a child gives them a different definition, they go with the adult’s, knowing that adults are more knowledgeable in this realm than kids. If the source is trustworthy, kids believe the claim; if the source is untrustworthy, they reject the identical claim. That’s a reasonable way to operate; since we can’t be experts about everything, it makes sense to trust people we trust.
The same sort of childish psychology can trip you up when it comes to scientific information, though. Few people immerse themselves in the voluminous scientific literature about, say, evolution. People who reject evolution are doing so because they haven’t escaped the childish notion that everything has a purpose for its existence (which violates the purposelessness of evolutionary processes), and because they evaluate obscure information by the source that brings it to them. In this case, many of those who deny the fact of evolution are rejecting the sources that argue in its favor—those godless, secular-humanist, elitist, amoral scientists and the media that channel them. They are rarely evaluating the evidence themselves. (I don’t mean to tar only creationists with the brush of childish thinking. Many Americans who say they believe that evolution is real and that it operates through natural selection cannot accurately describe either evolution or natural selection; they just trust the sources that make that claim.)
What all this means is that resistance to science starts in childhood and can easily persist into adulthood. That’s most likely to occur when the scientific claim is in dispute within a society (because it challenges a religious dogma, most obviously), if there is a nonscientific alternative that makes more intuitive sense, if that alternative is championed by people you trust and if the scientific claim is pushed by people you don’t. Evolution clashes with our childish notion that everything has a purpose and a design, so it has one strike against it from the start. It is championed by people widely viewed as elitist and godless and with a stake in the outcome (more funding for their research, triumphing over religion); strike two. The alternative, creationism, is backed by respected religious and political leaders with no obvious horse in the race; strike three.
Whenever people ask me what’s important to know about science, my answer is never the long list of facts—from heliocentrism to the genetic code—that passes for science standards in so many schools today. What people need to know about science is what it means to think scientifically—how to evaluate evidence that goes counter to their intuition and hopes, how to break out of childish thinking patterns. Being able to do that, much more than being able to explain how earthquakes arise, is true science literacy.