There is a lot of discussion in the media these days about fake news. The reason why this topic has gotten so much attention is that when people hear a report that contains information that later turns out to be false, that information continues to have a big impact on people’s beliefs. This persistence of false information is called the continued influence effect. For example, many people continue to believe in the link between autism and childhood vaccinations, even though the one study demonstrating this link was found to be fraudulent.
Not surprisingly, a lot of research has been done trying to figure out what might reduce the continued influence effect. A paper by Man-Pui Sally Chan, Christopher Jones, Kathleen Hall Jamieson, and Dolores Albarracin in the November 2017 issue if Psychological Science looked across the many studies on this topic by doing what is called a meta-analysis.
The authors found 52 studies involving over 6,500 participants. They explored three key factors from these studies. First, to what degree were people encouraged to think extensively about the false information when it was presented? Second, to what degree were people encouraged to think extensively about the information debunking the false information? Third, were people simply told that the original information was false or were they given an elaborate message debunking the false information?
The researchers were interested in two influences of finding out that information is false. First, there is a debunking effect. That is, does finding out the initial information was false decrease the strength of people’s belief in the false information? Second, there is a persistence effect. That is does the false information continue to have some impact on beliefs later?
Some of the results of the meta-analysis were not that surprising.
When people are encouraged to think extensively about the false information when they encounter it, the information is more resistant to debunking later, and its effect on future beliefs persists.
When people are encouraged to develop counterarguments to the false information when it is being debunked, then the debunking effect is stronger, and the false information has less impact on future beliefs.
Giving an elaborate debunking message, though, had mixed effects. As you might expect, the more elaborate the message, the stronger the debunking effect. That is, an elaborate message decreased people’s beliefs in the false information. Surprisingly, though, an elaborate message actually increased the long-term persistence of the false information. So, the elaborate message seemed to solidify the effect of the false information.
One of the main messages of this analysis is that false information is hard to eliminate. If people think about the information when they first encounter it, then it sticks in memory. It then requires real effort to eliminate the influence of that information later. Unfortunately, giving an elaborate message for why the false information was encountered in the first place could actually backfire by increasing the long-term persistence of the false information. It is not entirely clear why elaborate debunking messages don’t work well. That seems like a good avenue for future research.
All the more reason, then, to be careful where you get your news.
Chan, M.S., Jones, C.R., Jamieson, K.H., & Albarracin, D. (2017). Debunking: A meta-analysis of the psychological efficacy of messages countering misinformation. Psychological Science, 28(11), 1531-1546.