In the first condition, participants read about either climate change or human evolution. These are topics on which liberals tend to be welcoming and conservatives more hostile.
The second condition presented science topics more likely to be favored by conservatives and distrusted by liberals—hydraulic fracking or nuclear power. Nisbet and colleagues chose these topics because they tend to reveal a large conservative/liberal split on public-opinion polls.
In the third condition, participants read about an ideologically neutral topic—either astronomy or geology. "There's not a lot of liberals and conservatives screaming about how Pluto is no longer a planet," Nisbet says explaining why astronomy is a neutral subject.
Here are some examples of what they saw.
After the participants read through the site, they were asked: 1) what they thought about the information, 2) whether they found themselves arguing with that information, and 3) how much trust they had in the scientific community.
In the nuclear-energy-fracking condition, liberals "had a more negative emotional experience than conservatives, resisted the information more than the conservatives," Nisbet says. They also indicated a lower trust in science than the liberals in the ideological neutral condition (the geology-astronomy condition). That's right: When liberals are confronted with topics they tend to disagree with, they begin to distrust the science.
"The difference between liberals and conservatives is not that one has biases and one does not," Nisbet says. "It's that we may have biases against specific topics." Conservatives may be seen as antiscience, but that perception arises because scientific topics that are most often discussed are those that most readily offend the conservative worldview.
When conservatives read about evolution or climate change, they too reacted negatively, but their reactions were stronger (i.e., more negative). Nisbet says that could be because climate change and evolution are more salient in everyday discussions than fracking and nuclear power.
More troubling, Nisbet finds evidence that political discussion on scientific issues may make everyone more skeptical of science. Even liberals, who reported they believe in climate change and evolution, were more skeptical of science in the climate-change-evolution condition than in the neutral geology-astronomy condition. "Both liberals and conservatives had lower trust in science after the exposure to that information," Nisbet says. "Politicizing science may reduce trust for everybody, because it starts raising questions over whether science is being used for political reasons on one side or another."
So what does this all mean for public discourse? Knowing that everyone is susceptible to partisan bias does not excuse the misuse of facts or the outright dismissal of a scientific consensus. It's important to recognize that the psychological pressure to adhere to a partisan worldview may be stronger than the forces of logic. And that's a bias everyone is susceptible to.
Have empathy for those you disagree with. They are not stupid (well, maybe sometimes). Just human.
*Vaccination issues, interestingly, don't fall along usual Democratic/Republicans lines. Majorities in each party support vaccination requirements. Opinions seem to be sorted by age. Even so, Rand Paul was framing the issue around a common Republican trope: the right of an individual to chose, over a government recommendation.