Senator Inhofe (R-Okla.) pitched a snowball on the floor of the United States Senate last month.
This was his way of disputing that 2014 was the warmest year on earth and that human-caused climate change is happening. Inhofe’s beliefs are contrary to the overwhelming scientific consensus that climate change is happening and caused primarily by human pollution.
But many conservative Americans share Senator Inhofe’s view.
Is this dismissal of scientific evidence and distrust of scientists unique to ideological conservatives—or can it happen among ideological liberals too?
There are two main explanations for ideological divides about science between liberals and conservatives.
The first focuses on the perceived Republican war on science, purported to have emerged in the late 1990s.
The claim is that conservatives—because of what their ideology does to their brains—are inherently predisposed to reject scientific evidence and to distrust the scientific community.
The second, competing explanation suggests that who trusts science, and how much, is dependent on which scientific topics are dominating the political and media debate at a given time.
This explanation has two premises—that public attention to different scientific issues rises and falls over time depending on events (such as scientific discoveries) and on the activities of different actors in the public debate (advocacy groups, politicians, and the mass media)—and that conservatives and liberals can both be biased in how they process scientific information or trust scientists.
Motivated to be biased
Underlying both explanations is a theory—motivated political reasoning—that argues that the desire to reach conclusions consistent with one’s prior beliefs leads us to process information perceived as inconsistent with those beliefs in an emotionally biased manner.
As a result, we not only discount or dismiss scientific information inconsistent with our ideology; we may also distrust and attack its source(s).
Furthermore, and contrary to popular belief, this biased processing is most likely to occur among people who have greater cognitive and reasoning capabilities – not less.
Where the two sets of explanations for ideological divides on science differ is on how motivated reasoning leads to bias.
The first explanation assumes that conservatives are inherently anti-science as they tend to be more dogmatic and close-minded compared to liberals. They are therefore more “motivated” to reject scientific information that clashes with their world view and distrust its sources (in other words, scientists).
In contrast, the second thesis argues that though there are some nuanced psychological differences between liberals and conservatives, it would be a mistake to overstate them. Liberals are viewed as no less likely to respond to scientific information in biased manner than conservatives.
Testing our partisan brains
Our own study focused on the second explanation for ideological divides and tested whether conservative and liberal trust in science varies by topic.
Recruiting a diverse group of 1,500 adults from a national online panel of volunteers, participants were randomly assigned to read scientifically accurate statements about different science topics.
Some participants read about issues exhibiting a significant partisan divide, including climate change, evolution, nuclear power, and hydraulic fracturing (fracking) of natural gas, while others read about issues that tend to be viewed as ideologically neutral, namely geology and astronomy.
Nuclear power and fracking are often seen by liberals as threatening their environmental values. Evolution and climate change are more often contested by conservatives because they challenge the social and economic beliefs associated with their ideology.
We went into our experiment expecting that liberals and conservatives would experience negative emotional reactions when reading statements challenging their views, which would increase their skepticism to the claim.
Each of these factors would lead individuals to feel more distrustful of the source of the unwelcome information, the scientific community.
Unsurprisingly, we found that conservatives who read statements about climate or evolution had a stronger negative emotional experience and reported greater motivated resistance to the information as compared to liberals who read the same statements and other conservatives who read statements about geology or astronomy.
This in turn lead these conservatives to report significantly lower trust in the scientific community as compared to liberals who read the same statement or conservatives who read statements about ideologically neutral science.
Significantly, we found a similar pattern amongst liberals who read statements about nuclear power or fracking. And like conservatives who read statements about climate change or evolution, they expressed significantly lower levels of trust in the scientific community as compared to liberals who read the ideologically-neutral statements.
Biased attitudes toward scientific information and trust in the scientific community were evident among liberals and conservatives alike, and these biases varied depending on the science topic being considered.
An additional distressing finding was that though liberals who read statements about climate change and evolution reported greater trust in science than conservatives who did the same, they also reported significantly less trust in the scientific community than liberals who read ideologically neutral statements about geology or astronomy.
This suggests that highly partisan, high profile science can result in an overall loss of public confidence in the scientific community, even amongst those likely to trust the evidence.
We wish to stress that demonstrating that both conservatives and liberals are prone to responding to ideologically unpalatable scientific information in a biased matter is not an excuse for either side to do so.
We note in particular that our findings neither exempt nor validate the well-organized and heavily funded “climate denialist movement.” This movement engages in extensive public communication campaigns and lobbying efforts intended to misrepresent the science and scientific consensus about the issue; it funds and targets political candidates; and it attempts to intimidate climate scientists.
Lessons for science communicators
We end with two important lessons for science communicators that come out of our study.
The first is that political journalism too often treats science like a political issue to be debated by non-experts in televised partisan theater. This type of media coverage about scientific issues often obscures the actual scientific evidence and consensus and unfortunately only deepens polarization by providing partisan cues for both conservatives and liberals.
Our study’s findings suggest that such intensive, polarizing media attention depresses the public‘s confidence in the scientific community for liberals and conservatives alike.
The second lesson is that that science communicators who target conservatives specifically as somehow uniquely deficient when it comes to understanding science turn the focus to a clash of ideologies and away from promoting communication that bridges ideological gaps about science issues—and yes we think such gaps can be bridged!
Demonizing a third of the population in science policy debates by claiming they have an insurmountable psychological deficit does nothing to promote a solution to the challenges of effective science communication—and unfortunately represents our human biases at work.