When the facts change
DOI: 10.1063/PT.5.010024
Once during the Great Depression, someone accused the economist John Maynard Keynes of abandoning his former views on monetary policy, his specialty. With characteristic wit he replied, “When the facts change, I change my mind. What do you do, Sir?”
Keynes’s retort would barely raise an eyebrow in the world of science. Whatever physicists thought before 1887 about the existence of the ether, they would, at the very least, have had to adjust their views after Albert Michelson and Edward Morley’s decisive experiment in that year.
Indeed, scientists are so used to giving up cherished theories in the face of contradictory experiments that they sometimes forget that nonscientists are less deferential toward facts. A study published recently in the Journal of Risk Research underlines that difference.
The study’s authors—Dan Kahan of Yale University, Hank Jenkins-Smith of the University of Oklahoma, and Donald Braman of the George Washington University—set out to discover the extent to which people’s political values influence their confidence in climate change experts.
Survey respondents were given a questionnaire to establish which of two core political philosophies they adhered to: individualism or egalitarianism. They were also asked to rate the credibility of experts who were either skeptical or sure that mankind is causing Earth’s climate to warm up.
The National Science Foundation funded the study and issued a press release , which summarized the results in this way:
In the study, subjects with individualistic values were over 70 percentage points less likely than ones with egalitarian values to identify the scientist as an expert if he was depicted as describing climate change as an established risk. Likewise, egalitarian subjects were over 50 percentage points less likely than individualistic ones to see the scientist as an expert if he was described as believing evidence on climate change is unsettled.
Study results were similar when subjects were shown information and queried about other matters that acknowledge “scientific consensus.” Subjects were much more likely to see a scientist with elite credentials as an “expert” when he or she took a position that matched the subjects’ own cultural values on risks of nuclear waste disposal and laws permitting citizens to carry concealed guns in public.
The results didn’t surprise me. In the eyes of the general public, science isn’t special; the question of whether global warming is happening isn’t qualitatively different from the question of whether drugs should be legalized? Facts and values are involved in both questions, but in answering them, nonscientists weigh values more.
