The online media environment is changing from offline traditional news consumption to consuming news via online media characterized by an exploding amount of information and news source options. Concerns for fake news, echo chambers, filter bubbles and polarization have been raised due to this change. This thesis studies the underlying cognitive biases of belief polarization via the most used social media news site: Facebook. In order to measure the influence of confirmation bias and social proof bias on belief polarization, a new experimental design is introduced which includes a renewed indirect approach to measure polarization. The experiment replicates processes regarding the consumption of news via Facebook’s news feed. The results indicate that the consumption of attitude-confirming news via Facebook contributes to belief polarization. In this case, the chosen attitude object is the legalization of XTC in the Netherlands, but the experimental design could be applied to any attitude object in every country. The unique design of the experiment enables the analysis of possible different weight attachments towards attitude-confirming (treatment 1) and attitude-disconfirming (treatment 2) news due to confirmation bias, while keeping the news content used within the two treatments fixed. The analysis shows that confirmation bias contributes to belief polarization via Facebook. The consumption of pro-legalization news has a significantly different effect when it confirms the reader’s attitude than when it disconfirms the reader’s attitude. However, for the against-legalization news no significant difference in effects has been found. Therefore, future research should investigate multiple news articles and attitude objects to make further claims about the different weight attachments to news caused by confirmation bias. Furthermore, OLS regressions demonstrate that for both people that agree and disagree with the legalization of XTC, the exposure to a confirming news article, compared to a disconfirming news article, causes their initial beliefs to polarize. Finally, the influence of social proof bias could not be tested as the coefficients analyzing the effect of the number of likes on a news post for this specific attitude object were influentially correlated. Although this is unfortunate, it is discovered that the perceived trust in the online news and the importance attached to the given attitude object could influence belief polarization online as well. Consequently, in addition to some valuable insights regarding belief polarization, an up-to-date research design is provided for future research regarding belief polarization, confirmation bias and social proof bias.

B. Tereick
hdl.handle.net/2105/49487
Business Economics
Erasmus School of Economics

L.W.P. van den Bosch. (2019, November 8). The effect of confirmation bias and social proof on belief polarization via Facebook’s news feed.. Business Economics. Retrieved from http://hdl.handle.net/2105/49487