Feb 10, 2011
Is Scientific Evidence or Subjective Experience a More Effective Way to Convince Someone of a Scientific Fact?
Although almost all scientists agree that global warming is occurring, according to a 2010 Gallup poll, only half of American adults report holding such a belief. Given that people seem not to simply consult expert opinion, what variables influence people’s belief?
In our research, we find that people’s scientific beliefs can be influenced by their subjective experience, even when that experience provides them with no diagnostic information. For example, we find that when people feel warmer—either because they are out in the hot sun or even because they are in an overheated room—they believe in global warming more. Our results suggest that warmth influences belief because it causes people to more vividly imagine what a hot world would be like. The clarity of this simulation, in turn, makes people more likely to believe in global warming. In another experiment, we found that participants who were led to experience thirst by eating pretzels were more likely to agree that desertification and drought will increasingly threaten people’s ability to find fresh drinking water. This further validates the finding that people will judge a certain condition of the world as more likely if it fits with what they are experiencing at that moment.
Although our research documents how subjective experience can influence scientific belief, it is important to note that our studies do not compare the role of subjective experience with the role of scientific evidence. If people were presented with scientific evidence in our studies, it is likely that the evidence would also influence people’s belief.
Let us consider two factors that may make subjective experience an especially effective method for convincing people of a scientific fact.
First, subjective experience is most likely to influence beliefs that are informed by a process of imagination or simulation. Our results suggest that people’s belief in global warming is informed by imagining what a hot world would be like. If people are unable to simulate an outcome or process, however, then subjective experience may play less of a role. For example, the belief that HIV turns into AIDS is unlikely to be informed by someone’s subjective experience.
Second, if people are motivated not to believe scientific evidence because it challenges their broader belief system, then subjective experience may be more effective in “sneaking under the radar.” We found that feeling warm influences liberals and conservatives similarly. If our participants were presented with scientific evidence, however, it is very likely that those participants who were motivated not to believe in global warming would doubt the evidence that was presented to them.
Although there is no doubt that scientific evidence is an important method for convincing people of scientific facts, our research suggests that factors that facilitate the ability to picture what that future event would look and feel like may at times exert a strong (if not stronger) effect.
Jane Risen is a professor of behavioral science at the University of Chicago Booth School of Business.