Photo: Andrzej Wojcicki/Science Photo Library

There is a huge gap in opinion between experts and the American public on the subject of genetically modified (GM) organisms — that is, crops which have been genetically altered to add or enhance desirable characteristics.

It’s such a big gap, in fact, that one of the only points of comparison for such a divide is belief about climate change. As the psychologists Sydney E. Scott, Yoel Inbar, and Paul Rozin point out in a new paper in Perspectives on Psychological Science (draft PDF available here), “A recent survey of U.S. adults and scientists found that only 37% of the public thought genetically modified food was safe to eat, whereas 88% of [the American Association for the Advancement of Science] members thought it was.” There’s a similar divide when it comes to the question of how GM crops affect the environment — even though “independent scientific reviews of the environmental risks of GM agriculture have not yet uncovered meaningful risks to the natural environment above and beyond those of conventional (i.e., non-GM) agriculture,” Americans widely believe that GM crops are environmentally problematic.

These are some pretty damaging misconceptions. As many journalists and researchers have noted, while genetically modified organisms (GMOs) need to be used responsibly, like any other technology or agriculture technique, they can offer some pretty vital benefits, especially in places where it’s difficult to grow a lot of food. And the relentless focus on GMOs, as I have argued, lets big companies like Chipotle off the hook, allowing them to wring up virtue-points on an issue that doesn’t really matter, sometimes at the expense of issues that do matter. (Will Saletan’s mammoth Slate effort documenting misinformation about GMOs is the most important must-read on this subject.)

In light of all that, researchers like Scott, Inbar, and Rozin are hoping to better understand where GMO fears come from. For this particular study, the trio decided to examine how fears of GMOs tap into our deepest ideas about disgust, purity, and certain things being “sacred.” They were specifically curious about so-called “absolute moral values” — moral values people hold that they consider to be so important that they are “evidence insensitive,” as researchers like Jonathan Haidt have put it. Evidence will not sway people out of these beliefs, because they come from such a gut-level place. For some people, a moral absolute might be an aversion to burning an American flag; for others, an aversion to calling a racial minority an ethnic slur.

Because disgust is one of the most profound drivers of our emotions, and can short-circuit more “logical” thought and discourse (scare quotes because in our heads, many of these categories bleed into each other and don’t feel separate), absolute moral values are often disgust-related.

Some of the experiments Haidt and researchers in his orbit are really illuminating here. For example, in past research they have asked participants gross-sounding questions, such as whether it would ever be acceptable for a brother and sister to have consensual sex, or for a family to eat its dog as a meal. And as Haidt recounts in The Righteous Mind: Why Good People Are Divided by Politics and Religion (a must-read book), respondents will often quickly come up with reasons why these things would never be acceptable: “What if they have a kid and the kid has a genetic abnormality because of the incest?” for example. To which the experimenter will be trained to respond with something like “They’re using foolproof contraception,” or “The sister is sterile” — that is, to make it clear that no one is being harmed by the gross act in this particular instance, and therefore there’s no “rational,” evidence-based argument against it.

Doesn’t matter, Haidt and his colleagues and grad students have found over and over and over. The respondents will usually still find a way to wriggle out of calling the behavior in question acceptable, even when it’s clear no living thing is being harmed by the act in question. There are moral lines people won’t cross, even when they have every assurance that no tangible harm will result — morality is more than just a cost-benefit analysis.

So, back to the study: “We argue that [the] combination of minimal knowledge and strong conviction” Americans have about GMOs, the researchers write, “is sensible if, for many people, attitudes about GM are the result of absolute moral values rather than consequence-based calculations.” To test this idea, they surveyed a nationally representative sample of 1,022 respondents, and ended up with a final sample of 859. The participants were asked about various scenarios in which people hypothetically ate GMO foods (sometimes on purpose, sometimes by accident), and the researchers gauged their disgust level with these scenarios, as well as their overall level of propensity for disgust — “trait disgust,” as researchers call it.

The subsequent number-crunching revealed “three main conclusions,” according to the researchers:

First, we find that a majority of the 64% of American participants who oppose GM can be described as moral absolutists. These individuals indicate that they would maintain their opposition for any balance of risks and benefits; that is, they profess to be evidence insensitive. Second, GM opponents, especially absolutist opponents, tend to feel heightened disgust, both generally and regarding the consumption of genetically modified foods specifically. Finally, disgust and disgust sensitivity predict support for legal restrictions of GM above and beyond explicit risk-benefit assessments.

So taken together, what does this all mean? The results suggest it’s going to be really, really hard to convince skeptical Americans that GMO foods are okay to eat, because people’s beliefs about them are so driven by disgust rather than by any real understanding of the issues. I don’t mean this to imply that all GMO opponents are animated by these concerns, but rather that the respondents in this study — a representative slice of the American population — are pretty specifically indicating that they’re not interested in hearing the pro- or neutral-GMO case, because they are so disgusted by the prospect of putting GM foods in their bodies.

So maybe don’t tell them that they are probably already eating GM foods, anyway.