The researchers had a politically balanced group evaluate the quality of news sources, but also isolated the evaluations of Republican-leaning subjects: > Crit

The researchers had a politically balanced group evaluate the quality of news sources, but also isolated the evaluations of Republican-leaning subjects: > Critically, this unbiased measure produces similar results to those described above using professional fact-checker ratings: when using the ratings of a politically balanced group of laypeople, the average quality of domains shared by people who used Trump hashtags was 2.17 s.d. lower than people who used Biden hashtags (t-test, t(8,943) = 1.0 × 102, P < 0.0001; Fig. 1b). Even when creating a purposefully right-biased quality measure by only using the trustworthiness ratings of Republican laypeople, we still find a qualitatively similar pattern: the average quality of domains shared by people who used Trump hashtags was 1.29 s.d. lower than people who used Biden hashtags (t(8,943) = 61.1, P < 0.0001; Extended Data Fig. 1). To further contextualize the magnitude of this difference, we discretize our politically balanced layperson quality ratings to classify each of the 60 rated domains as low versus high quality (Extended Data Fig. 2), and find that the median Trump hashtag poster shared four times more links to low-quality websites compared with the median Biden hashtag poster. > Our findings are not unique to the use of Biden versus Trump hashtags to classify users’ political orientation: we find high correlations between sharing lower-quality news sources and conservative ideology as estimated on the basis of the Twitter accounts the users follow39 or the news sites that the users share12,40 (expert ratings, 0.73 < r < 0.88 depending on partisanship/ideology measure, P < 0.001 for all; politically balanced layperson ratings, 0.73 < r < 0.82 depending on partisanship/ideology measure, P < 0.001 for all; see the Methods for methodological details).