Skip to main content Accessibility help

Party Affiliation, Partisanship, and Political Beliefs: A Field Experiment


Partisanship is strongly correlated with attitudes and behavior, but it is unclear from this pattern whether partisan identity has a causal effect on political behavior and attitudes. We report the results of a field experiment that investigates the causal effect of party identification. Prior to the February 2008 Connecticut presidential primary, researchers sent a mailing to a random sample of unaffiliated registered voters who, in a pretreatment survey, leaned toward a political party. The mailing informed the subjects that only voters registered with a party were able to participate in the upcoming presidential primary. Subjects were surveyed again in June 2008. Comparing posttreatment survey responses to subjects’ baseline survey responses, we find that those reminded of the need to register with a party were more likely to identify with a party and showed stronger partisanship. Further, we find that the treatment group also demonstrated greater concordance than the control group between their pretreatment latent partisanship and their posttreatment reported voting behavior and intentions and evaluations of partisan figures. Thus, our treatment, which appears to have caused a strengthening of partisan identity, also appears to have caused a shift in subjects’ candidate preferences and evaluations of salient political figures. This finding is consistent with the claim that partisanship is an active force changing how citizens behave in and perceive the political world.

Corresponding author
Alan S. Gerber is Professor, Department of Political Science, Institution for Social and Policy Studies, Yale University, 77 Prospect Street, P.O. Box 208209, New Haven, CT 06520-8209 (
Gregory A. Huber is Associate Professor, Department of Political Science, Institution for Social and Policy Studies, Yale University, 77 Prospect Street, P.O. Box 208209, New Haven, CT 06520-8209 (
Ebonya Washington is Associate Professor, Department of Economics, Yale University. P.O. Box 208264, New Haven, CT 06520-8264 (
Hide All
Abrams, Dominic. 1994. “Political Distinctiveness: An Identity Optimizing Approach.” European Journal of Social Psychology 24: 357–65.
Allsop, Dee, and Weisberg, Herbert. 1988. “Measuring Change in Party Identification in an Election Campaign.” American Journal of Political Science 32: 9961017.
Alwin, Duane F., and Krosnick, Jon A.. 1991. “Aging, Cohorts, and the Stability of Sociopolitical Orientations over the Life Span.” American Journal of Sociology 97: 169–95.
Angrist, Joshua D., and Pischke, Jorn-Steffen. 2008. Mostly Harmless Econometrics: An Empiricist's Companion. Princeton, NJ: Princeton University Press.
Angrist, Joshua D., and Pischke, Jorn-Steffen. 2009. “A Note on Bias in Just Identified IV with Weak Instruments.” Mimeo.
Asch, Solomon E. 1951. “Effects of Group Pressure upon the Modification and Distortion of Judgment.” In Groups, Leadership, and Men, ed. Guetzkow, H.. Pittsburgh, PA: Carnegie, 177–90.
Bartels, Larry. 2000. “Partisanship and Voting Behavior, 1952–1996.” American Journal of Political Science 44: 3550.
Bartels, Larry. 2002. “Beyond the Running Tally: Partisan Bias in Political Perceptions.” Political Behavior 24: 117–50.
Beasley, Ryan K., and Joslyn, Mark R.. 2001. “Cognitive Dissonance and Post-decision Attitude Change in Six Presidential Elections.” Political Psychology 22: 521–40.
Brader, Ted, and Tucker, Joshua A.. 2001. “The Emergence of Mass Partisanship in Russia, 1993–1996,” American Journal of Political Science 45: 6983.
Brewer, Marilynn B. 1979. “In-group Bias in the Minimal Intergroup Situation: A Cognitive–Motivational Analysis.” Psychological Bulletin 17: 475–82.
Brewer, Marilynn, and Brown, Rupert J.. 1998. “Intergroup Relations.” In The Handbook of Social Psychology, 4th ed., vol. 2, eds. Gilbert, D. T., Fiske, S. T., and Lindzey, G.. Boston: McGraw-Hill, 554–94.
Brody, Richard, and Rothenberg, Lawrence. 1988. “The Instability of Partisanship: An Analysis of the 1980 Presidential Election.” British Journal of Political Science 18: 445–66.
Brown, Rupert J., Tajfel, Henri, and Turner, John C.. 1980. “Minimal Group Situations and Inter-group Discrimination: Comments on the Paper by Aschenbrenner and Schaefer.” European Journal of Social Psychology 10: 399414.
Bullock, John G., Green, Donald P., and Ha, Shang E.. 2010. “Yes, But What's the Mechanism? (Don't Expect an Easy Answer).” Journal of Personality and Social Psychology 98: 550–58.
Burden, Barry C., and Greene, Steven. 2000. “Party Attachments and State Election Laws.” Political Research Quarterly 53: 6376.
Campbell, Angus, Converse, Philip, Miller, Warren, and Stokes, Donald. 1960. The American Voter. New York: Wiley.
Carsey, Thomas M., and Layman, Geoffrey C.. 2006. “Changing Sides or Changing Minds? Party Identification and Policy Preferences in the American Electorate.” American Journal of Political Science 50: 464–77.
Cialdini, Robert B. 2001. “The Science of Persuasion.” Scientific American 284: 7681.
Cialdini, Robert B., and Goldstein, Noah J.. 2004. “Social Influence: Compliance and Conformity.” Annual Review of Psychology 55: 591621.
Converse, Philip. 1976. The Dynamics of Party Support: Cohort-analyzing Party Identification. Beverly Hills, CA: Sage.
Cowden, Jonathan A., and McDermott, Rose M.. 2000. “Short-term Forces and Partisanship.” Political Behavior 22: 197222.
Dancygier, Rafaela, and Saunders, Elizabeth N.. 2006. “A New Electorate? Comparing Preferences and Partisanship between Immigrants and Natives.” American Journal of Political Science 50: 962–81.
Duflo, Esther, Glennerster, Rachel, and Kremer, Michael. 2008. “Using Randomization in Development Economics Research: A Toolkit.” In Handbook of Development Economics, 4, eds. Schultz, T. P. and Strauss, J.. Amsterdam: North-Holland, 3896–962.
Erikson, Robert S. 2004. “Economic Voting: Micro and Macro Perspectives.” Presented at the Annual Meeting of the Political Methodology Society, Stanford University.
Fiorina, Morris P. 1981. Retrospective Voting in American National Elections. New Haven, CT: Yale University Press.
Fiorina, Morris P. 2002. “Parties and Partisanship: A 40-year Retrospective.” Political Behavior 24: 93115.
Franklin, Charles H., and Jackson, John E.. 1983. “The Dynamics of Party Identification.” American Political Science Review 77: 957–73.
Gelman, Andrew, and King, Gary. 1993. “Why Are American Presidential Campaign Polls So Variable When Votes Are So Predictable?British Journal of Political Science 23: 409–51.
Gerber, Alan S., and Green, Donald P.. 2000. “The Effects of Canvassing, Telephone Calls, and Direct Mail on Voter Turnout: A Field Experiment.” American Political Science Review 94: 653–63.
Gerber, Alan S., Green, Donald P., and Kaplan, Edward H.. 2004. “The Illusion of Learning from Observational Research.” In Problems and Methods in the Study of Politics, eds. Shapiro, I., Smith, R., and Massoud, T.. New York: Cambridge University Press, 251–73.
Gerber, Alan S., Green, Donald P., and Larimer, Christopher W.. 2008. “Social Pressure and Voter Turnout: Evidence from a Large-scale Field Experiment.” American Political Science Review 102: 3348.
Gerber, Alan S., and Huber, Gregory A.. 2010. “Partisanship, Political Control, and Economic Assessments.” American Journal of Political Science 54: 153–73.
Goren, Paul. 2005. “Party Identification and Core Political Values.” American Journal of Political Science 49: 881–96.
Green, Donald, Palmquist, Bradley, and Schickler, Eric. 2002. Partisan Hearts and Minds: Political Parties and the Social Identities of Voters. New Haven, CT: Yale University Press.
Greene, Steven. 1999. “Understanding Party Identification: A Social Identity Approach.” Political Psychology 20: 393403.
Greene, Steven. 2002. “The Social-psychological Measurement of Partisanship.” Political Behavior 24: 171–97.
Greene, Steven. 2004. “Social Identity Theory and Party Identification.” Social Science Quarterly 85: 136–53.
Hogg, Michael, and Abrams, Dominic. 1988. Social Identifications. London: Routledge.
Huckfeldt, Robert, and Sprague, John. 1987. “Networks in Context: The Social Flow of Political Information.” American Political Science Review 81: 1197–215.
Jackson, John E. 1975. “Issues, Parties, and Presidential Votes.” American Journal of Political Science 19: 161–85.
Jacoby, William G. 1988. “The Impact of Party Identification on Issue Attitudes.” American Journal of Political Science 32: 643–61.
Jennings, M. Kent, and Niemi, Richard G.. 1974. The Political Character of Adolescence: The Influence of Families and Schools. Princeton, NJ: Princeton University Press.
Kaplan, Thomas. 2008. “As Candidates Scramble for Delegates, Connecticut Primary Gains Spotlight,” New York Times. (Accessed September 30, 2008).
Katz, Richard S., Neimi, Richard G., and Newman, David. 1980. “Reconstructing Past Partisanship in Britain.” British Journal of Political Science 10: 505–15.
Keith, Bruce. 1986. “The Partisan Affinities of Independent ‘Leaners.’British Journal of Political Science 16: 155–85.
Keith, Bruce, Magleby, David, Nelson, Candice, Orr, Elizabeth, Westlye, Mark, and Wolfinger, Raymond. 1992. The Myth of the Independent Voter. Berkeley: University of California Press.
Kelly, Caroline. 1988. “Intergroup Differentiation in a Political Context.” British Journal of Social Psychology 27: 319–32.
Kelly, Caroline. 1989. “Political Identity and Perceived Intragroup Homogeneity.” British Journal of Social Psychology 28: 239–50.
Kessel, John. 1968. The Goldwater Coalition. Indianapolis, IN: Bobbs-Merrill.
Lau, Richard R., Andersen, David J., and Redlawsk, David P.. 2008. “An Exploration of Correct Voting in Recent U.S. Presidential Elections.” American Journal of Political Science 52: 395411.
Lau, Richard R., and Redlawsk, David P.. 2001. “Advantages and Disadvantages of Cognitive Heuristics in Political Decision Making.” American Journal of Political Science 45: 951–71.
Layton, Lindsay. 2008. “CT: Small Prize, But Big-name Visits.” February 4. In The Trail: A Daily Diary of Campaign 2008. (Accessed September 30, 2008).
Levendusky, Matthew. 2009. The Partisan Sort: How Liberals Became Democrats and Conservatives Became Republicans. Chicago: University of Chicago Press.
Lupia, Arthur. 1992. “Busy Voters, Agenda Control, and the Power of Information.” American Political Science Review 86: 390403.
MacKuen, Michael, Erikson, Robert, and Stimson, James. 1989. “Macropartisanship.” American Political Science Review 83: 1125–42.
Michelitch, Kristin. 2010. “Do Elections Manipulate Patterns of Inter-ethnic or Inter-partisan Discrimination? A Field Experiment on Price Bargaining in Africa.” New York University, Typescript.
Miller, Warren E. 1991. “Party Identification, Realignment, and Party Voting: Back to Basics.” American Political Science Review 85: 557–68.
Miller, Arthur H., and Wattenberg, Martin P.. 1983. “Measuring Party Identification: Independent or No Partisan Preference?American Journal of Political Science 27: 106–21.
Mullen, B., Brown, Rupert, and Smith, C.. 1992. “Ingroup Bias as a Function of Salience, Relevance, and Status: An Integration.” European Journal of Social Psychology 22: 103–22.
Niemi, Richard G., and Jennings, M. Kent. 1991. “Issues and Inheritance in the Formation of Party Identification.” American Journal of Political Science 35: 970–88.
Norrander, Barbara, and Wilcox, Clyde. 1993. “Rallying around the Flag and Partisan Change: The Case of the Persian Gulf War.” Political Research Quarterly 46: 759–70.
Page, Benjamin I., and Jones, Calvin C.. 1979. “Reciprocal Effects of Policy Preferences, Party Loyalties and the Vote.” American Political Science Review 73: 1071–89.
Rahn, Wendy M. 1993. “The Role of Partisan Stereotypes in Information Processing about Political Candidates.” American Journal of Political Science 37: 472–96.
Redlawsk, David P. 2002. “Hot Cognition or Cool Consideration? Testing the Effects of Motivated Reasoning on Political Decision Making.” Journal of Politics 64: 1021–44.
Stone-Romero, Eugene F., and Rosopa, Patrick J.. 2008. “The Relative Validity of Inferences about Mediation as a Function of Research Design Characteristics.” Organizational Research Methods 11: 326–52.
Sumner, William G. 1906. Folkways. Boston: Ginn.
Tajfel, Henri. 1978. “Social Categorization, Social Identity, and Social Comparisons.” In Differentiation between Social Groups, ed. Tajfel, H.. London: Academic, 6176.
Tajfel, Henri, Flament, C., Billig, M. G., and Bundy, R. F.. 1971. “Social Categorization: An Intergroup Phenomenon.” European Journal of Social Psychology 1: 149–77.
Tajfel, Henri, and Turner, John C.. 1986. “The Social Identity Theory of Intergroup Behaviour.” In Psychology of Intergroup Relations, eds. Worchel, S. and Austin, W. G.. Chicago: Nelson-Hall, 724.
Tesser, Abraham. 1978. “Self-generated Attitude Change.” Advances in Experimental Social Psychology 11: 181227.
Tesser, Abraham, and Leone, Christopher. 1977. “Cognitive Schemas and Thought as Determinants of Attitude Change.” Journal of Experimental Social Psychology 13: 340–56.
Tomz, Michael, and Sniderman, Paul M.. 2005. “Brand Names and the Organization of Mass Belief Systems.” Stanford University, Typescript.
Weisberg, Herbert F., and Greene, Steven H.. 2003. “The Political Psychology of Party Identification.” In Electoral Democracy, eds. MacKuen, M. B. and Rabinowitz, G.. Ann Arbor: University of Michigan Press, 83124.
Weisberg, Herbert F., and Smith, Charles E. Jr. 1991. “The Influence of the Economy on Party Identification in the Reagan Years.” Journal of Politics 53: 1077–92.
Whitefield, Stephen, and Evans, Geoffrey. 1999. “Class, Markets and Partisanship in Post-Soviet Russia: 1993–96.” Electoral Studies 18: 155–78.
Wlezien, Christopher, Franklin, Mark, and Twiggs, Daniel. 1997. “Economic Perceptions and Vote Choice: Disentangling the Endogeneity.” Political Behavior 19: 717.
Yamagishi, Toshio, Mifune, Nobuhiro, Liu, James H., and Pauling, Joel. 2008. “Exchanges of Group-based Favours: Ingroup Bias in the Prisoner's Dilemma Game with Minimal Groups in Japan and New Zealand.” Asian Journal of Social Psychology 11: 196207.
Zaller, John R. 1992. The Nature and Origins of Mass Opinion. New York: Cambridge University Press.
Recommend this journal

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

American Political Science Review
  • ISSN: 0003-0554
  • EISSN: 1537-5943
  • URL: /core/journals/american-political-science-review
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed