Skip to main content
    • Aa
    • Aa

The Role of Evidence in Politics: Motivated Reasoning and Persuasion among Politicians


Does evidence help politicians make informed decisions even if it is at odds with their prior beliefs? And does providing more evidence increase the likelihood that politicians will be enlightened by the information? Based on the literature on motivated political reasoning and the theory about affective tipping points, this article hypothesizes that politicians tend to reject evidence that contradicts their prior attitudes, but that increasing the amount of evidence will reduce the impact of prior attitudes and strengthen their ability to interpret the information correctly. These hypotheses are examined using randomized survey experiments with responses from 954 Danish politicians, and results from this sample are compared to responses from similar survey experiments with Danish citizens. The experimental findings strongly support the hypothesis that politicians are biased by prior attitudes when interpreting information. However, in contrast to expectations, the findings show that the impact of prior attitudes increases when more evidence is provided.

Hide All

Department of Political Science, Aarhus University (emails:;;;; Support for this research was provided by the Aarhus University Supplementary Pool. Data replication sets are available at and online appendices are available at

Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

British Journal of Political Science
  • ISSN: 0007-1234
  • EISSN: 1469-2112
  • URL: /core/journals/british-journal-of-political-science
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Type Description Title
Supplementary Materials

Baekgaard supplementary material

 Word (27 KB)
27 KB


Altmetric attention score

Full text views

Total number of HTML views: 20
Total number of PDF views: 257 *
Loading metrics...

Abstract views

Total abstract views: 4070 *
Loading metrics...

* Views captured on Cambridge Core between 18th August 2017 - 23rd October 2017. This data will be updated every 24 hours.