A recent study from the University of Colorado Boulder has explored how readers at partisan news sites respond to challenging events that contradict their beliefs. The researchers found that readers of both liberal and conservative news sites are more likely to reject or discount information that goes against their existing beliefs, and those exposed exclusively to partisan news will do so even more strongly than readers exposed to a more balanced media diet.

To test this, the researchers used an online experiment where participants were randomly assigned to read one of two articles that either supported or challenged their political beliefs. The participants were asked to rate their agreement with the article, as well as their perceptions of the source's credibility and bias.

The results showed that, overall, readers were more likely to agree with articles that supported their beliefs and to reject articles that challenged them. This effect was especially strong for those who only read partisan news sites, suggesting that a steady diet of one-sided news can lead to increased confirmation bias.

The researchers also found that readers of partisan news sites were more likely to perceive the source of a challenging article as biased, while those exposed to a balanced media diet were more likely to perceive the source as credible.

These findings highlight the importance of exposure to a diverse range of viewpoints and information sources in order to maintain critical thinking skills and avoid the echo chamber effect of only consuming news that confirms existing beliefs.