Differences of opinion between those who consider themselves conservative or liberal often appear to be unbridgeable, and recent research suggests the split is greater among the more educated, through what psychologists call “motivated reasoning”, in which information is rejected or moulded – consciously or otherwise – to support a particular worldview.
A new study in the journal Nature Human Behaviour, however, claims that by presenting a fact in the form of a consensus, people will shift their opinions significantly towards an accepted scientific “norm”.
The study took as its basis one of the most divisive issues of our time: anthropogenic climate change.
Previous polling has indicated that those who think of themselves as conservative tend to be more sceptical of climate change. Yet by presenting them with a factual consensus – such as the statement “97% of climate scientists have concluded that human-caused global warming is happening” – the researchers find that they will change their perceptions significantly.
“The vast majority of people want to conform to societal standards,” says Sander van der Linden, the study’s lead author, from Britain’s University of Cambridge psychology department. “It’s innate in us as a highly social species.”
Van der Linden and his co-authors, Anthony Leiserowitz and Edward Maibach, from Yale and George Mason universities in the US, conclude that social facts such as demonstrating a consensus can act as a “gateway belief”, allowing a gradual recalibration of private attitudes.
“Information that directly threatens people’s worldview can cause them to react negatively and become further entrenched in their beliefs,” van der Linden explains. “This ‘backfire effect’ appears to be particularly strong among highly educated US conservatives when it comes to contested issues such as man-made climate change.
“It is more acceptable for people to change their perceptions of what is normative in science and society. Previous research has shown that people will then adjust their core beliefs over time to match. This is a less threatening way to change attitudes, avoiding the backfire effect that can occur when someone’s worldview is directly challenged.”
The researchers conducted an online survey of more than 6000 people in the US, balanced according to gender, age, region, education, ethnicity, political ideology and socio-demographic characteristics.
Political ideology was measured on a five-point scale: very conservative, somewhat conservative, moderate, somewhat liberal, liberal.
Respondents were presented with three randomised blocks of questions about popular media topics, to mask the true purpose of the study. There were questions about new state-level regulations around drink driving, about the new Apple watch, and several questions about climate change, including the key dependent variable: perceptions of the scientific norm.
Respondents were then told about a large database of media statements, and that they would randomly be shown one of these statements. In reality, the only statement shown was “97% of climate scientists have concluded that human-caused global warming is happening”.
Later, they were asked: “To the best of your knowledge, what percentage of climate scientistshave concluded that human-caused global warming is happening?”
The researchers found what they call “a robust pattern”, that “conservatives update their beliefs in line with the scientific norm more than liberals do”. To some extent, they say, this could partly be attributable to a ceiling effect among liberals; that is, liberals recognise that there is a scientific consensus more than conservatives do in general.
They found that attitudes towards scientific belief on climate change among self-declared conservatives were, on average, 35 percentage points lower than the actual scientific consensus of 97%. Among liberals it was 20 percentage points lower.
They also found a small additional negative effect: when someone is highly educated and conservative, they judge scientific agreement to be lower still.
However, once the treatment group was exposed to the “social fact” of overwhelming scientific agreement, higher-educated conservatives shifted their perception of the scientific norm by 20 percentage points to 83% — almost in line with post-treatment liberals.
The added negative effect of conservatism plus high education was completely neutralised through exposure to the fact of scientific agreement around man-made climate change.
“Scientists as a group are still viewed as trustworthy and non-partisan across the political spectrum in the US, despite frequent attempts to discredit their work through ‘fake news’ denunciations and underhand lobbying techniques deployed by some on the right,” says van der Linden.
“Our study suggests that even in our so-called post-truth environment, hope is not lost for the fact. By presenting scientific facts in a socialised form, such as highlighting consensus, we can still shift opinion across political divides on some of the most pressing issues of our time.”