Genetically modified organisms (GMOs) have met with enormous public opposition over the past two decades. Many people believe that GMOs are bad for their health – even poisonous – and that they damage the environment. This is in spite of overwhelming scientific evidence that proves that GMOs are safe to eat, and that they bring environmental benefits by making agriculture more sustainable. Why is there such a discrepancy between what the science tells us about GMOs, and what people think? To be sure, some concerns, such as herbicide resistance in weeds and the involvement of multinationals, are not without basis, but they are not specific to GMOs. Hence, another question we need to answer is why these arguments become more salient in the context of GMOs.

I recently published a paper, with a group of Belgian biotechnologists and philosophers from Ghent University, arguing that negative representations of GMOs are widespread and compelling because they are intuitively appealing. By tapping into intuitions and emotions that mostly work under the radar of conscious awareness, but are constituent of any normally functioning human mind, such representations become easy to think. They capture our attention, they are easily processed and remembered and thus stand a greater chance of being transmitted and becoming popular, even if they are untrue. Thus, many people oppose GMOs, in part, because it just makes sense that they would pose a threat.

In the paper, we identify several intuitions that may affect people’s perception of GMOs. Psychological essentialism, for instance, makes us think of DNA as an organism’s “essence” - an unobservable and immutable core that causes the organism’s behaviour and development and determines its identity. As such, when a gene is transferred between two distantly related species, people are likely to believe that this process will cause characteristics typical of the source organism to emerge in the recipient. For example, in an opinion survey in the United States, more than half of respondents said that a tomato modified with fish DNA would taste like fish (of course, it would not).

Essentialism clearly plays a role in public attitudes towards GMOs. People are typically more opposed to GM applications that involve the transfer of DNA between two different species (“transgenic”) than within the same species (“cisgenic”). Anti-GMO organizations, such as NGOs, exploit these intuitions by publishing images of tomatoes with fish tails or by telling the public that companies modify corn with scorpion DNA to make crispier cereals.

Intuitions about purposes and intentions also have an impact on people’s thinking about GMOs. They render us vulnerable to the idea that purely natural phenomena exist or happen for a purpose that is intended by some agent. These assumptions are part and parcel of religious beliefs, but in secular environments they lead people to regard nature as a beneficial process or entity that secures our wellbeing and that humans shouldn’t meddle with. In the context of opposition to GMOs, genetic modification is deemed “unnatural” and biotechnologists are accused of “playing God”. The popular term “Frankenfood” captures what is at stake: by going against the will of nature in an act of hubris, we are bound to bring enormous disaster upon ourselves.

Disgust also affects people’s attitudes towards GMOs. The emotion probably evolved, at least in part, as a pathogen avoidance mechanism, preventing the body from consuming or touching harmful substances. We feel repelled by things that possibly contain or indicate the presence of pathogens such as bodily fluids, rotten meat, and maggots. This would explain why disgust operates on a hair trigger: it is better to forego an edible meal under the misguided assumption that it is contaminated, than to consume sickening, or even lethal, food that is erroneously thought to be safe. Hence, disgust can be elicited by completely innocuous food.

GMOs probably trigger disgust because people view genetic modification as a contamination. The effect is enforced when the introduced DNA comes from a species that is generally deemed disgusting, such as rats or cockroaches. However, DNA is DNA, whatever its source. The impact of disgust explains why people feel more averse towards GM food than other GM applications, such as GM medicine. Once disgust is elicited, the argument that GMOs cause cancer or sterility, or that they will contaminate the environment, becomes very convincing and is often used. Disgust also affects moral judgments, leading people to condemn everyone who is involved with the development and commercialization of GM products. Because people have no conscious access to the emotional source of their judgments, they consequently look for arguments to rationalize them.

Our cognitive analysis is not intended to debunk every anti-GMO claim a priori. A particular GM application may have unwanted effects, which can also be the case with a product of organic or conventional farming. The risks and benefits should be assessed on a case-to-case basis, regardless of the process. The current applications have been proven to be safe. One may take issue with the involvement of multinationals or be concerned about herbicide resistance, but these issues have to do with how GM technology is sometimes applied and certainly do not warrant resistance to the technology and to GMOs in general. The emotional and intuitive basis of anti-GMO sentiments however prevents people from making these distinctions.

The impact of intuitions and emotions on people’s understanding of, and attitudes towards, GMOs has important implications for science education and communication. Because the mind is prone to distorting or rejecting scientific information in favour of more intuitive beliefs, simply transmitting the facts will not necessarily persuade people of the safety, or benefits, of GMOs, especially if people have been subjected to emotive, anti-GMO propaganda.

In the long run, education starting from a young age and specifically targeted at tackling common misconceptions might immunize the population against unsubstantiated anti-GMO messages. Other concerns can be addressed and discussed in the wider context of agricultural practices and the place of science and technology in society. However, for now, the best way to turn the tide and generate a more positive public response to GMOs is to play into people’s intuitions as well. For instance, emphasizing the benefits of current and future GM applications — improved soil structures because herbicide resistant crops require less or no tilling, higher income for farmers in developing countries, reduced vitamin A deficiency, virus and drought resistance, to name a few — might constitute the most effective approach to changing people’s minds. Given the benefits and promises of GM technology, such a change is much needed.