It is possible to persuade Conservatives to care about the environment, say psychologists - as long as you pitch it in terms of purity, rather than moral obligation.
It seems that images of dirty drinking water do more to persuade conservatives to recycle than do images of devastated forests - because the forests don't disgust them in the same way.
"These findings offer the prospect of pro-environmental persuasion across party lines," says University of California, Berkeley social psychologist Robb Willer.
"Reaching out to conservatives in a respectful and persuasive way is critical, because large numbers of Americans will need to support significant environment reforms if we are going to deal effectively with climate change, in particular."
The findings go some way to explain why so many people remain unmoved by the usual line that there's a moral obligation to care about the natural environment and protect it from harm.
Conservatives, it seems, respond better to arguments that focus on purity, patriotism and reverence for a higher authority.
In their first experiment, the team recruited 187 men and women via Craigslist, who rated their political ideology on a scale of 'extremely liberal' to 'extremely conservative'. They then rated the morality of such activities as recycling a water bottle versus throwing it in the garbage.
The results, unsurprisingly, showed that liberals are more prone to viewing sustainability as a moral issue than are conservatives.
Next, though, they randomly gave participants one of three articles. One described the destruction wreaked on the environment by humans and pitched protection of the environment as a moral obligation. Images accompanying the text were of a forest with tree stumps, a barren coral reef and drought-cracked land.
Another article stressed how pollution has contaminated Earth and people’s bodies, and argued for cleaning up and purifying the environment. The images here showed a person drinking filthy water, a city under a cloud of pollution and a forest full of garbage. A neutral article talked about the history of neckties.
Participants were then asked to rate how strongly they felt certain emotions, including disgust, in response to what they’d read - and to report how strongly they agreed or disagreed with such statements as 'It is important to protect the environment'.
Overall, the study found that the purity-themed message inspired conservatives to feel higher levels of disgust, which in turn increased their support for protecting the environment.
The findings bear out the results of a study last year that found conservatives are much more easily disgusted than liberals. It probably comes as less of a surprise to Republican speech-writers.