Why Do People Believe Scientifically Untrue Things?

Because to do otherwise would be immoral.

Ronald Bailey | March 15, 2013

You hear a lot about the politicization of science, but the real problem is the moralization of science. The New York University psychologist Jonathan Haidt has made a compelling case that moral differences drive partisan debates over scientific issues. Dan Kahan and others at the Yale Cultural Cognition Project have identified cultural differences that bias how people assimilate information. Together, Haidt and Kahan’s research suggests that what you believe about a scientific debate signals to like-minded people that you are on their side and are therefore a good and trustworthy person. Unfortunately, this means that the factual accuracy of beliefs is somewhat incidental to the process of moral signaling.

For an illustration, consider a recent skirmish between Skeptic editor Michael Shermer and Mother Jones writer Chris Mooney. Shermer, whose political views lean toward libertarianism, wrote a column for Scientific American titled “The Liberal War on Science,” noting the left’s tendency to deny human cognitive evolution and the safety of biotech crops and nuclear power. Mooney, author of a book called The Republican War on Science, retorted with a story headlined “There is No Such Thing as a Liberal War on Science.” The right’s denial of evolutionary biology and man-made global warming, Mooney argued, are much more consequential for public policy. While acknowledging that a substantial percentage of Democrats don’t believe in human evolution or man-made global warming either, Mooney took comfort in the fact that “considerably fewer Democrats than Republicans get the science wrong on these issues.”
Kahan identifies the ideological left as people who tend to have egalitarian or communitarian views. Egalitarians want to reduce disparities between people, and communitarians believe that society is obliged to take care of everyone. People holding these cultural values are naturally biased toward collective action to address inequality and the lack of solidarity. When the results of scientific research are perceived to perturb those values, it should be no surprise that left-leaners have a greater tendency to moralize them, to favor government intervention to control them, and to disdain conservatives who resist liberal moralizing.
Haidt’s moral survey data suggests that ideological conservatives have a greater tendency to moralize about purity and sanctity than do liberals. This may be so, but it’s pretty clear that liberals are not immune from concerns about purity and sanctity. While conservatives moralize about the purity and sanctity of sex and reproduction, liberals fret about the moral purity of foods and the sanctity of the natural world.
One particularly powerful moralizing tool that is chiefly deployed by progressives is the precautionary principle. Mooney blandly writes that this “is not an anti-science view, it is a policy view about how to minimize risk.” Beliefs about how much risk people should allowed to take or to be exposed to are moral views. In fact, as Kahan and his colleagues have shown, the strong urge to avoid scientific and technological risk is far more characteristic of people who have egalitarian and communitarian values. The precautionary principle is not a neutral risk analysis tool; it is an embodiment of left-leaning moral values.
Let’s look at what scientific research says—and does not say—about the moralized issues of climate change, biological evolution, nuclear power, genetically modified crops, exposure to synthetic chemicals, concealed carry of guns, vaccines, video games, fracking, organic foods, and sex education. I chose this list largely because I could find relevant ideological polling data and majority scientific opinions. Applying Mooney’s standard of seeing whether fewer of one ideological tendency gets the science wrong, we find that Democrats are less wrong on four issues, Republicans are less wrong on six, and the parties are tied on one.
Climate change: The majority of climate scientists believe that human activity is causing the earth’s temperatures to increase. A recent Pew Research poll found that two-thirds of Americans also believe that the earth is warming. But a deep partisan divide yawns between conservatives and liberals on the cause of the warming: Only 16 percent of conservative Republicans believe that human activity is responsible, whereas 77 percent of liberal Democrats do. Moderate Republicans and Democrats accept human responsibility by 38 and 51 percent, respectively. Advantage: Democrats.
Evolution: Both Shermer and Mooney cite a 2012 Gallup Poll that found that 46 percent of Americans are young Earth creationists—that is, believe that God created humans beings in their present form within the past 10,000 years. These constitute 41 percent of Democrats and 58 percent of Republicans. Adding those partisans of both parties who are intelligent design creationists, i.e., believe that God guided the process of evolution, the poll shows 73 percent of Democrats and 89 percent of Republicans holding creationist beliefs. In fact, 78 percent of Americans are either young Earth or intelligent design creationists. A 2009 Pew Research poll produced numbers that were lower but still high, showing that 52 percent of Democrats and 65 percent of Republicans can be counted as either intelligent design or young Earth creationists.
The Pew Research poll also reported that 87 percent of scientists believe that humans evolved through entirely natural processes, whereas only 8 percent thought that God guided the process. Advantage: Democrats.
Nuclear power: A 2012 Gallup Poll found that 72 percent of Republican think that nuclear power is generally safe, compared to just 45 percent of Democrats. Given these views, is it not surprising that 64 percent of Republicans and 41 percent of Democrats favored expanding this source of carbon-free energy. A 2009 Pew Research poll reported that 70 percent of scientists favored building more nuclear power plants. Although it seems unlikely that scientists would favor nuclear power if they thought it unsafe, perhaps the Pew poll is measuring cost/benefit views rather than safety views. I have not been able to uncover recent surveys of expert opinion with regard to the safety of nuclear power plants, but in a survey done more than a year after the Three Mile Island nuclear plant meltdown, 90 percent of the scientists surveyed said the nuclear power should proceed. A 1986 poll of radiation health scientists reported that the vast majority believed “the public's fear of radiation is substantially greater than realistic, that TV, newspapers and magazines substantially exaggerate the dangers of radiation.”
In 1993, a study titled “Decidedly Different” contrasted the views found in survey data gathered from the public and from members of the American Nuclear Society. The survey asked both groups, “How likely do you think it is that activities at the nation’s nuclear facilities will in the future cause health problems for those who live near such activities?” The responses were measured on a scale of 1 to 10, with 1 being not likely to 10 being extremely likely. Thirty-three percent of the public picked 10; 40 percent of the experts picked 1. Overall, 69 percent of the public thought such future health effects were likely and 80 percent of the experts did not.
Recall Mooney’s claim that there is “no currently pressing issue...where the left is monolithically in denial of basic science, or where this drives mainstream political policy—e.g., drives the stance of most elected Democrats.” It is true that the Obama administration has been pro-nuclear, but looking around the country it’s easy to find elected Democrats who take the opposite position. For example, Massachusetts attorney general Martha Coakley sued to close down the Pilgrim plant, Vermont Governor Peter Shumlin is pushing to close the Vermont Yankee plant, and New York Governor Andrew Cuomo favors shutting down the two Indian Point reactors in 2013 and 2015. These Democratic politicians seem pretty “mainstream,” and there are no comparable officials from the GOP taking similar stances. Advantage: Republicans.
Biotech crops: Every independent scientific group that has ever evaluated biotech crops has found them to be safe for people and the environment. Sadly, polling data suggests that both Democrats and Republicans have been spooked by anti-biotech disinformation campaigns. The most recent polling on this issue I could find was a 2006 survey by the Pew Trusts that reported 48 percent of Republicans believe that biotech foods are safe, compared to 28 percent who did not. Democrats are just slightly less likely to think biotech foods are safe, with 42 percent saying they are and 29 percent saying they aren’t. As far as mainstream impact goes, the California Democratic Party endorsed last year’s Proposition 37, which would have required the labeling of all foods made with ingredients from biotech crops. Advantage: Republicans.
Synthetic chemicals: The chief worry about synthetic chemicals, stoked originally by Rachel Carson in her 1962 book Silent Spring, has traditionally been cancer. Yet as the American Cancer Society notes, “Exposure to carcinogenic agents in occupational, community, and other settings is thought to account for a relatively small percentage of cancer deaths—about 4% from occupational exposures and 2% from environmental pollutants (man-made and naturally occurring).” A recent article the journal Lancet Oncology argued that costly regulatory efforts to reduce exposures to trace amounts of man-made chemicals divert resources from truly effective measures to prevent cancer, such as modifying lifestyle factors such as smoking, obesity, and sunlight exposure.
What do experts think? Polling data is scarce on the ground, but a 2009 survey of the members of the Society of Toxicology decisively rejected the assertion that exposure to any level of chemicals is unacceptable by 92 percent to 8 percent. In addition, 87 percent the society’s members disagreed with the claim that organic and natural products are safer, and 81 percent disagreed with idea that detecting any level of chemicals in a person’s body shows a health risk.