Nevertheless, partisanship persisted: fake news warnings help briefly, but bias returns with time

Politically oriented “fake news”—false stories or headlines created to support or attack a political position or person—is increasingly being shared and believed on social media. Many online platforms have taken steps to address this by adding a warning label to articles identified as false, but past research has shown mixed evidence for the effectiveness of such labels, and many prior studies have looked only at either short-term impacts or non-political information. This study tested three versions of fake news labels with 541 online participants in a two-wave study. A warning that came before a false headline was initially very effective in both discouraging belief in false headlines generally and eliminating a partisan congruency effect (the tendency to believe politically congenial information more readily than politically uncongenial information). In the follow-up survey two weeks later, however, we found both high levels of belief in the articles and the re-emergence of a partisan congruency effect in all warning conditions, even though participants had known just two weeks ago the items were false. The new pre-warning before the headline showed some small improvements over other types, but did not stop people from believing the article once seen again without a warning. This finding suggests that warnings do have an important immediate impact and may work well in the short term, though the durability of that protection is limited. Supplementary Information The online version contains supplementary material available at 10.1186/s41235-021-00315-z.