Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

The limited effects of testimony on political persuasion


The procedure of witness testimony and cross-examination under oath, which is institutionalized in the court system and in Congress, may increase the credibility of political messages by strengthening perceived incentives for truth-telling. In this paper, I test the hypothesis that testimony can increase the persuasiveness of empirical claims in realistic political settings. However, results from a large number of experiments, including numerous national survey experiments, indicate that describing statements as being made in congressional or court testimony rarely generates significant change in respondents’ beliefs or attitudes—a result that is robust to numerous experimental design variations.

This is a preview of subscription content, log in to check access.


  1. Althaus, S. L. (1998). Information effects in collective preferences. American Political Science Review, 92(3), 545–558.

  2. Bartels, L. M. (2002). Beyond the running tally: partisan bias in political perceptions. Political Behavior, 24(2), 117–150.

  3. Boudreau, C. (2006). Jurors are competent cue-takers: how institutions substitute for legal sophistication. International Journal of Law in Context, 2(3), 293–304.

  4. Boudreau, C. (2009). Making citizens smart: when do institutions improve unsophisticated citizens’ decisions? Political Behavior, 31, 287–306.

  5. Brambor, T., Clark, W. R., & Golder, M. (2006). Understanding interaction models: improving empirical analyses. Political Analysis, 14(1), 63–82.

  6. Carpini, M. X. D., & Keeter, S. (1996). What Americans know about politics and why it matters. New Haven: Yale University Press.

  7. Cunningham, B. (2003). Re-thinking objectivity. Columbia Journalism Review, 42(2), 24–32.

  8. Druckman, J. N. (2001). The implications of framing effects for citizen competence. Political Behavior, 23(3), 225–256.

  9. Edwards, K., & Smith, E. E. (1996). A disconfirmation bias in the evaluation of arguments. Journal of Personality and Social Psychology, 71(1), 5–24.

  10. Gelman, A., Pasarica, C., & Dodhia, R. (2002). Let’s practice what we preach: turning tables into graphs. The American Statistician, 56(2), 121–130.

  11. Gerber, A., & Malhotra, N. (2008). Do statistical reporting standards affect what is published? Publication bias in two leading political science journals. Quarterly Journal of Political Science, 3, 313–326.

  12. Gilens, M. (2001). Political ignorance and collective policy preferences. American Political Science Review, 95(2), 379–396.

  13. Gill, J. (1999). The insignificance of null hypothesis significance testing. Political Research Quarterly, 52(3), 647–674.

  14. Grimmer, J. (2010). A Bayesian hierarchical topic model for political texts: measuring expressed agendas in senate press releases. Political Analysis, 18(1), 1–35.

  15. Howell, W. G., & West, M. R. (2009). Educating the public. Education Next, 9(3), 41–47.

  16. Jackman, S., & Sniderman, P. M. (2006). The limits of deliberative discussion: a model of everyday political arguments. Journal of Politics, 68(2), 272–283.

  17. Jerit, J., & Barabas, J. (2006). Bankrupt rhetoric: how misleading information affects knowledge about social security. Public Opinion Quarterly, 70(3), 278–303.

  18. Knight, K. (2000). Mathematical statistics. London/Boca Raton: Chapman & Hall/CRC.

  19. Kuklinski, J. H., Quirk, P. J., Jerit, J., Schwieder, D., & Rich, R. F. (2000). Misinformation and the currency of democratic citizenship. Journal of Politics, 62(3), 790–816.

  20. Kull, S., Ramsay, C., & Lewis, E. (2003). Misperceptions, the media, and the Iraq war. Political Science Quarterly, 118(4), 569–598.

  21. Kunda, Z. (1990). The case for motivated reasoning. Psychological Bulletin, 108(3), 480–498.

  22. Lebo, M. J., & Cassino, D. (2007). The aggregated consequences of motivated reasoning and the dynamics of partisan presidential approval. Political Psychology, 28(6), 719–746.

  23. Lord, C. G., Ross, L., & Lepper, M. R. (1979). Biased assimilation and attitude polarization: the effects of prior theories on subsequently considered evidence. Journal of Personality and Social Psychology, 37(11), 2098–2109.

  24. Lupia, A. (1994). Shortcuts versus encyclopedias: information and voting behavior in California insurance reform elections. American Political Science Review, 88(1), 63–76.

  25. Lupia, A. (2004). Can political institutions increase citizens’ competence? Findings from a formal model and two experiments. In Morris, I., Oppenheimer, J. A., & Soltan, K. (Eds.), Politics from anarchy to democracy: rational choice in political science (pp. 132–156). Stanford: Stanford University Press.

  26. Lupia, A., & McCubbins, M. D. (1998). The democratic dilemma: can citizens learn what they need to know? New York: Cambridge University Press.

  27. Martin, A. D., & Quinn, K. M. (2006). Applied Bayesian inference in R using MCMCpack. R News, 6, 2–7.

  28. Mattei, L. R. W. (1998). Gender and power in American legislative discourse. Journal of Politics, 60(2), 440–461.

  29. Molden, D. C., & Higgins, E. T. (2005). Motivated thinking. In Holyoak, K. J., & Morrison, R. G. (Eds.), The Cambridge handbook of thinking and reasoning (pp. 295–317). Cambridge: Cambridge University Press.

  30. Mondak, J. J. (1993a). Public opinion and heuristic processing of source cues. Political Behavior, 15(2), 167–192.

  31. Mondak, J. J. (1993b). Source cues and public approval: the cognitive dynamics of public support for the Reagan agenda. American Journal of Political Science, 37(1), 186–212.

  32. Nyhan, B., & Reifler, J. (forthcoming). When corrections fail: the persistence of political misperceptions. Political Behavior.

  33. Plummer, M., Best, N., Cowles, K., & Vines, K. (2006). CODA: convergence diagnosis and output analysis for MCMC. R News, 6(1), 7–11. http://CRAN.R-project.org/doc/Rnews/.

  34. Polk, L. D., Eddy, J., & Andre, A. (1975). Use of congressional publicity in Wisconsin district. Journalism Quarterly, 52(3), 543–546.

  35. Pornpitakpan, C. (2004). The persuasiveness of source credibility: a critical review of five decades’ evidence. Journal of Applied Social Psychology, 34(2), 243–281.

  36. Rahn, W. M. (1993). The role of partisan stereotypes in information processing about political candidates. American Journal of Political Science, 37(2), 472–496.

  37. Schaffner, B. F., & Streb, M. J. (2002). The partisan heuristic in low-information elections. Public Opinion Quarterly, 66(4), 559–581.

  38. Sellers, P. J. (2000). Manipulating the message in the us congress. Harvard International Journal of Press Politics, 5(1), 22–31.

  39. Shapiro, R. Y., & Bloch-Elkon, Y. (2008). Do the facts speak for themselves? partisan disagreement as a challenge to democratic competence. Critical Review, 20(1), 115–139.

  40. Sides, J., & Citrin, J. (2007). How large the huddled masses? The causes and consequences of public misperceptions about immigrant populations. Paper presented at the 2007 annual meeting of the Midwest Political Science Association, Chicago, IL.

  41. Smith, E. R. A. N., & Squire, P. (1990). The effects of prestige names in question wording. Public Opinion Quarterly, 54(1), 97–116.

  42. Sniderman, P. M., & Theriault, S. (2004). The dynamics of political argument and the logic of issue framing. In Saris, W. E., & Sniderman, P. M. (Eds.), Studies in public opinion: gauging attitudes, nonattitudes, measurement error and change. Princeton: Princeton University Press.

  43. Sniderman, P. M., & Tomz, M. (2005). Brand names and the organization of mass belief systems. Working paper. Stanford: Stanford University.

  44. Taber, C. S., & Lodge, M. (2006). Motivated skepticism in the evaluation of political beliefs. American Journal of Political Science, 50(3), 755–769.

Download references

Author information

Correspondence to Brendan Nyhan.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Nyhan, B. The limited effects of testimony on political persuasion. Public Choice 148, 283–312 (2011). https://doi.org/10.1007/s11127-010-9655-0

Download citation


  • Social Security
  • Public Choice
  • Policy Opinion
  • High Posterior Density
  • Political Knowledge