Norbert L. Kerr


  • Ph. D. 1974 University of Illinois at Urbana-Champaign
  • Affiliations:
  • Research Interests:
    • Cooperative behavior in social dilemmas (current emphasis on the impact of the threat of social exclusion for encouraging cooperative behavior)
    • Social exclusion (current emphasis on how we detect and react to cues of social exclusion)
    • Small group task performance (current emphasis on enhancing group members' task-motivation)
    • Psychology and the law (emphasis on juror/jury decision making)
    • Hypothesis testing strategies in scientific research
  • Phone: (517) 256-8460;  voicemail (616) 439-0562
  • Office: 254 Psychology
  • e-mail:

I am currently (Summer, 2010) appointed half-time at Michigan State University and an Honorary Professor at the University of Kent in Canterbury. I am in the midst of a phased-retirement. I will be fully retired and assume emeritus status in the Fall of 2014. In the meantime, I am not accepting new graduate students as advisees, although I do continue to serve on a few graduate student committees (as non-chair).

My current work focuses primarily on five topics--group motivation gains, social dilemmas, social exclusion, juror/jury behavior, and a vaguely defined topic which we might call "how social psychologists (among others) write up their work".

1. Over 70 years ago, Otto Koehler provided evidence for intriguing group motivation gains. My current work (done in collaboration with Deborah Feltz and Brandon Irwin of the Department of Kinesiology) has been extending this phenomenon to increase motivation to exercise in exercise grouips using health video games.

2. My current social dilemma work has been focusing on the effectiveness of overt or subtle threats of social exclusion as a mechanism for social control in social dilemmas.

3. I've become interested in the "front end" of the sociometer--how we detect threats to our inclusionary status. We've done some work identifying the cues people use to communicate social rejection/marginalization.

4. With some colleagues in Law and Communications, I've been studying a number of questions, including a) what is the effect of allowing jurors to discuss trial evidence prior to jury deliberation?, b) does the heinousness of a crime bias juror decision making?, and c) how does the mode of presentation of information (e.g., physical exhibit vs. video images) alter jurors' reactions?

5. I continue to be interested in what I termed HARKing (hypothesizing after the results are known; cf. Kerr, 1998). We're currently doing some archival research to document the incidence and form that such HARKing takes in psychology.

Selected Recent Publications: A complete Vita is also available.

Kerr, N. L. (in press). Social dilemmas. To appear in Frontiers in Social Psychology (J. Levine, Editor). New York, NY: Psychology Press.


Feltz, D. L., Kerr, N. L., & Irwin, B. (2011). Buddy up: The Köhler Effect applied to health games. Journal of Sport and Exercise Psychology, 33(4), 506-526.


McDonald, M. M., Asher, B. D., Kerr, N. L., & Navarrete, C. D. (2011). Fertility and intergroup bias in racial and minimal group contexts: Evidence for shared architecture. Psychological Science, 22, 855-859.


Kerr, N. L., & Hertel, G. (2011). The Köhler Group Motivation Gain: How to Motivate the “Weak Links” in Groups. Social and Personality Psychology Compass, 5, 43-55.


Kerr, N. L., & Seok, D.-H. (2011). “…with a little help from my friends”: Interpersonal attraction and group motivation gain. Special Issue on “Excellence in Teams: How to Achieve Performance Gains in Working Groups,” Journal of Management Psychology, 26(3), 205-218.


Kerr, N. L. (2011). HARK! A Herald Sings…But Who’s Listening? In R. M. Arkin (Ed.), Most Underappreciated: 50 Prominent Social Psychologists Talk About Hidden Gems. New York, NY: Oxford University Press.


Kerr, N. L., & Tindale, R. S. (2011). Group-based forecasting?: A social psychological analysis. Special Issue on “Enhancing group-based judgemental forecasting: Processes and priorities,” G. Wright & G. Rowe (Eds.), International Journal of Forecasting, 27(1), 14-40.


Kerr, N. L. (2010). Juror emotion and juror judgment. In Richard L. Wiener & Brain H. Bornstein,  (Eds.), Emotion and the Law: Psychological Perspectives. 56th Nebraska Symposium on Motivation. Lincoln, NB: University of Nebraska Press.


Kerr, N. L. (2009). The Köhler effect. In J. M. Levine & M. A. Hogg (Eds.), Encyclopedia of Group Processes and Intergroup Relations. Sage: Thousand Oaks, CA.


Kerr, N. L. (2009). The sucker effect. In J. M. Levine & M. A. Hogg (Eds.), Encyclopedia of Group Processes and Intergroup Relations. Sage: Thousand Oaks, CA.


Kerr, N. L., Rumble, A. C., Park, E. S., Parks, C. D., Ouwerkerk, J. W., Gallucci, M., & van Lange, P. A. M. (2009). “One bad apple spoils the whole barrel”: Social exclusion as a remedy for the One Bad Apple Effect. Journal of Experimental Social Psychology, 45(4), 603-613.


Lount, R. B., Kerr, N. L., Messé, L. M., Seok, D.-H., & Park, E. S. (2008). An examination of the stability and persistence of the Köhler motivation gain effect. Group Dynamics: Theory, Research, and Practice. Vol 12(4), Dec 2008, 279-289.


Laughlin, P.R., Carey, H. R., & Kerr, N. L. (2008). Group-to-individual problem solving transfer. Group Processes and Intergroup Relations, Vol 11(3), Jul 2008, 319-330.


Kerr, N. L., Seok, D., Poulsen, J., Harris, D., & Messé, L. M.  (2008). Social ostracism and group motivation gain. European Journal of Social Psychology, Vol 38(4), Jun 2008, 736-746.


Kerr, N. L., & Levine, J. L. (2008). The detection of social exclusion: Evolution and beyond. Group Dynamics, Special Issue: Evolutionary Approaches to Group Dynamics. 12(1), 39-52.


Kerr, N. L., Boster, F., Callen, C. R., Braz, M. E., O’Brien, B., & Horowitz, I. (2008). Jury nullification instructions as amplifiers of bias. International Commentary on Evidence. (online publication at


Kerr, N. L., Messé, L. M., Seok, D., Sambolec, E., Lount, R. M., & Park, E. S. (2007).  Psychological mechanisms underlying the Köhler motivation gain. Personality and Social Psychology Bulletin, 33(6), 828-841.


Levine, J. M, & Kerr, N. L. (2007). Inclusion and exclusion: Implications for group processes. In A. E. Kruglanski and E. T. Higgins (Eds.), Social psychology: Handbook of basic principles (2nd ed.). New York: Guilford.


Horowitz, I. A., Kerr, N. L., Park, E. S., & Gockel, C. (2006). Chaos in the courtroom reconsidered: Emotional bias and juror nullification. Law & Human Behavior (Special Issue on Emotion and Legal Decision Making), 30(2), 163-181.


Kerr, N. L. (2006). Bridging social psychology: How and where? In P. van Lange (Ed.), Bridging Social Psychology. Mahweh, NJ :L. Erlbaum.


Ouwerkerk, J. W., Kerr, N. L., Gallucci, M., & Van Lange, P. A. M. (2005). Avoiding the social death penalty: Ostracism and cooperation in social dilemmas. In Williams, K. D., Forgas, J. P., & von Hippel, W. (Eds.), The social outcast: Ostracism, social exclusion, rejection, and bullying. New York: The Psychology Press.


Kerr, N. L., Messé, L. M., Park, E. S., & Sambolec, E. (2005). Identifiably, performance feedback and the Köhler effect. Group Processes and Intergroup Relations, 8(4), 375-390.

Kerr, N. L., & Bray, R. M. (2005). Simulation, realism, and the study of the jury. In Neil Brewer & Kipling Williams (Eds.), Psychology and law: An empirical perspective. New York: Guilford.

Kerr, N. L., & Tindale, R. S. (2004). Group performance and decision making. Annual Review of Psychology, 55, 623-655.

Kelley, Harold H; Holmes, John G; Kerr, Norbert L; Reis, Harry T; Rusbult, Caryl E; Van Lange, Paul A M. (2003). An atlas of interpersonal situations. New York: Cambridge University Press.

Baron, R. S., & Kerr, N. L. (2003). Group process, group decision, group action (2nd Ed.). Buckingham, UK: Open University Press.

Messe, Lawrence A; Hertel, Guido; Kerr, Norbert L; Lount, Robert B Jr; Park, Ernest S. (2002). Knowledge of partner's ability as a moderator of group motivation gains: An exploration of the Koehler discrepancy effect. Journal of Personality and Social Psychology. Jun; Vol 82(6): 935-946.

Wit, Arjaan P; Kerr, Norbert L. (2002). 'Me versus just us versus us all': Categorization and cooperation in nested social dilemmas. Journal of Personality and Social Psychology. Sep; Vol 83(3): 616-637.

Garst, Jennifer; Kerr, Norbert L; Harris, Susan E; Sheppard, Lori A. (2002). Satisficing in hypothesis generation. American Journal of Psychology. Vol 115(4): 475-500.

Hertel, G., & Kerr, N. L. (2001). Priming and in-group favoritism: The impact of normative scripts in the minimal group paradigm. Journal of Experimental Social Psychology, 37, 316-324.

Kerr, N. L., Aronoff, J., Messe, L. A. (2000). Methods of small group research. In H. Reis & C. Judd, Research methods in social psychology: A handbook. New York: Cambridge University Press.

Hertel, G., Kerr, N. L., Messé, L. A. (2000). Motivation gains in groups: Paradigmatic and theoretical advances on the Koehler effect. Journal of Personality and Social Psychology, 79, 580-601.

Kerr, N. L., Niedermeier, K., & Kaplan, M. (1999). Bias in jurors vs. juries: New evidence from the SDS perspective. Organizational Behavior and Human Decision Processes, 80, 70-86.

Niedermeier, K., Kerr, N. L., & Messe, L. A. (1999). Jurors' use of naked statistical evidence: Exploring bases and implications of the Wells Effect. Journal of Personality and Social Psychology, 76, 533-542.

Kerr, N. L. (1998). HARKing: Hypothesizing After the Results are Known. Personality and Social Psychology Review, 2, 196-217.

Kerr, N. L., Garst, J., Kiehle, D., & Harris, S. (1997). That still, small voice: Commitment to cooperateas an internalized vs. a social norm. Personality and Social Psychology Bulletin, 23,1300-1311.

Kerr, N. L. & Kaufman-Gilliland, C. (1997). "...and besides, I probably couldn't have made a difference anyway.": Rationalizing defection in social dilemmas. Journal of Experimental Social Psychology, 33, 211-230.

Kerr, N. L. (1996). "Does My Contribution Really Matter?": Efficacy in Social Dilemmas. In W. Stroebe & M. Hewstone (Eds.), European Review of Social Psychology (Vol. 7). Chichester: J. Wiley.

Kerr, N. L., & Kaufman-Gilliland, C. M. (1994). Communication, commitment, and cooperation in social dilemmas. Journal of Personality and Social Psychology, 66, 513-529.

Allison, S. & Kerr, N. L. (1994). Group correspondence biases and the provision of public goods. Journal of Personality and Social Psychology, 66, 688-698.

Kerr, N. L., MacCoun, R., & Kramer, G. P. (1996). Bias in judgment: Comparing individuals and groups. Psychological Review, 103, 687-719.

Kerr, N. L., Hymes, R. W., Anderson, A. B., & Weathers, J. E. (1995). Defendant-juror similarity and mock juror judgments. Law and Human Behavior, 19, 545-567.

Kerr, N. L., (1994). The effects of pretrial publicity on jurors. Judicature, 78, 120-127. (Reprinted in Eskridge, C. (Ed.) (1996). Concepts and issues in criminal justice. Los Angeles: Roxbury Press.)

Some Favorite Professional Links

Midwestern Psychological Association                          Social Psych at MSU
Social Psychology Network                                            School of Psychology at the University of Kent                                           
American Psychological Society