After they read scientific information stating that genetically modified foods are safe, 12 percent of the study’s participants said they felt such foods were less safe – not more, much to McFadden’s astonishment.
That’s partly because people form beliefs and often never let go of them, he said.
“This is critical and hopefully demonstrates that as a society we should be more flexible in our beliefs before collecting information from multiple sources,” McFadden said. “Also, this indicates that scientific findings about a societal risk likely have diminishing value over time.”
For the study, published in the current issue of the journal Food Policy, McFadden led a research project that surveyed 961 people across the U.S. via the Internet in April 2013.
To assess their beliefs about genetically modified foods, participants were asked to respond to statements such as: “Genetically modified crops are safe to eat.” To gauge their beliefs about humans and global warming, they responded to statements such as: “The Earth is getting warmer because of human actions.”
Then they were given scientific information about genetically modified foods and global warming.
For example, researchers showed them this quote from the National Research Council regarding genetically modified food: “To date, no adverse health effects attributed to genetic engineering have been documented in the human population.”
Respondents read several quotes about global warming, including this one from the American Association for the Advancement of Science: “The scientific evidence is clear: Global climate change caused by human activities is occurring now, and it is a growing threat to society.”
After reading statements from scientific groups, participants were asked about their beliefs regarding the safety of genetically modified foods. The choices ranged from “much less safe” to “much more safe.”
The results showed that before they received the information, 32 percent believed GM foods were safe to eat; 32 percent were not sure and 36 percent did not believe GM foods were safe to eat. After they received scientific information, about 45 percent believed genetically modified foods were safer to eat and 43 percent were not swayed by the information.
Then they were asked to assess the extent to which they believe human involvement caused global warming. They were given choices ranging from “much less involved” to “much more involved.”
The study showed that before they received the information, 64 percent believed human actions are causing global warming; 18 percent were not sure and 18 percent did not believe human actions are to blame. After receiving scientific information about global warming, about 50 percent of participants believed even more strongly that human actions lead to global warming, while 44 percent were not swayed by the information, the study showed.
“Possibly, the best indicator for whether a person will adopt scientific information is simply what a person believes before receiving the information,” McFadden said.