Prof. Ruth Katharina Ditlmann, Ph.D.

Former Staff Member of the Research Department

Research fields

Migration, Integration, and Intercultural Conflicts
National Identity | Intergroup Conflict and Conflict Resolution | Intergroup Contact | Psychological Nudging


2014 – 2015 Postdoctoral Fellow Department of Psychology and Woodrow Wilson School of Public and International Affairs Princeton University, Princeton, NJ

Since 10 2012 Senior Researcher at the WZB Berlin Social Science Center.

09 200709 2012 PhD student at the Yale University Social Psychology Department.

09 200705 2009 Mphil, MS student at the Yale University Social Psychology Department.

08 201009 2012 Visiting Research Scholar at the Columbia University Psychology Department.

10 200108 2007 Student of Diplom Psychologie at Universität Konstanz

08 200504 2006 Baden-Wuerttenberg CT Department of Higher Education Exchange Scholar Program and Cusanuswerk stipend for research internship at Yale University

08 200408 2005 DAAD (German Academic Exchange Service) Scholarship for an academic year at Yale University, Social Psychology Department..

Selected Publications

Alizade, J., Dancygier, R., & Ditlmann R. K. (in press). National penalties reversed: The local politics of responsiveness to immigrants. Journal of Politics.

Hässler, T., Ullrich, J., Bernardino, M., Shnabel, N., Van Laar, C., Valdenegro, D., Sebben, S., Tropp, L., Visintin, E.P., González, R., Ditlmann, R. K., Abrams, D. Selvanatha, H. P., Bankovic, M, Wright, S., Von Zimmermann, J., Pasek, M. H., Aydin, A. L., Žeželj, I., [… ] Ugarte, L.M. (2020). A large-scale test for the link between intergroup contact and social change. Nature Human Behaviour, 4(4), 380-386.

Kai Barron, Ruth Ditlmann, Stefan Gehrig, Sebastian Schweighofer-Kodritsch (2020): Explicit and implicit belief-based gender discrimination: A hiring experiment. WZB Discussion Paper SP II 2020–306.

Ditlmann, R. K., & Kopf-Beck, J. (2019). The meaning of being German: An inductive approach to national identity. Journal of Social and Political Psychology, 7(1), 423-447.

Ditlmann, Ruth/Samii, Cyrus/Zeitzoff, Thomas (2017): "Addressing Violent Intergroup Conflict from the Bottom Up?". In: Social Issues and Policy Review, Vol. 11, No. 1, S. 38-77.
Ditlmann, Ruth/Purdie-Vaughns, Valerie/Dovidio, John F./Naft, Michael J. (2017): "The Implicit Power Motive in Intergroup Dialogues about the History of Slavery". In: Journal of Personality and Social Psychology, Vol. 112, No. 1, S. 116-135.
Ditlmann, Ruth/Samii, Cyrus (2016): "Can Intergroup Contact Affect Ingroup Dynamics? Insights from a Field Study with Jewish and Arab-Palestinian Youth in Israel". In: Peace and Conflict - Journal of Peace Psychology, Vol. 22, No. 4, S. 380-392.
Ditlmann, Ruth Katharina/Levy Paluck, Elizabeth (2015): "Field experiments". In: James D. Wright (Ed.): International Encyclopedia of the Social & Behavioral Sciences, Vol. 9. Amsterdam u.a.: Elsevier, S. 128-134.
Ditlmann, Ruth K./Lagunes, Paul (2014): "The (Identification) Cards You Are Dealt. Biased Treatment of Anglos and Latinos Using Municipal-Issued versus Unofficial ID Cards". In: Political Psychology, Vol. 35, No. 4, S. 539-555. (Vorab online publiziert 19. August 2013)
Ditlmann, Ruth K./Mayville, Elena/Purdie-Vaughns, Valerie J. (2014): "Organizational and Individual Colorblindness Approaches to Past Injustice". In: Kecia M. Thomas/Victoria C. Plaut/Ny Mia Tran (Eds.): Diversity Ideologies in Organizations. Series in Applied Psychology. New York, NY/London: Routledge, S. 93-117.
Dovidio, John/Gaertner, Sam/Ditlmann, Ruth/West, Tessa (2012): "Intergroup Relations in Post-Conflict Context. How the Past Influences the Present (and Future)". In: Kai J. Jonas/Thomas A. Morton (Eds.): Restoring Civil Societies. The Psychology of Intervention and Engagement Following Crisis. Series Social Issues and Interventions. Chichester u.a.: Wiley Blackwell, S. 135-155.

Lagunes, P., Levin, B., & Ditlmann, R. (2012). Documenting the undocumented: A review of the United States’ first municipal ID program. Harvard Journal of Hispanic Policy, 24.

Dovidio, J. F., Gluszek, A., John, M. S., Ditlmann, R., & Lagunes, P. (2010). Understanding bias toward Latinos: Discrimination, dimensions of difference, and experience of exclusion. Journal of Social Issues, 66(1), 59 - 78.

Ditlmann, R. K., Purdie-Vaughns, V., & Eibach, R. (2010). Heritage and ideology-based national identites and their implications for immigrant citizen relations in the United States and in Germany. International Journal of Intercultural Relations, 35 (4), 395-405.

Purdie-Vaughns, V. & Ditlmann, R. K. (2010). Reflections on diversity science in social psychology. Psychological Inquiry 21(2), 153-159.

Purdie-Vaughns,V., Steele, C. M., Davies, P. G., Ditlmann, R. K., & Randall-Crosby, J. (2008). Social identity contingencies: How diversity cues signal threat or safety for African Americans in mainstream institutions. Journal of Personality and Social Psychology, 94(4), 615-630.


Addressing Violent Inter-Group Conflict from the Bottom Up?
Head: Ruth Katharina Ditlmann, Ph.D.
Cooperation with: Cyrus SamiiThomas Zeitzoff
Duration: 2016 - 2017
Funding: WZB

Stateways versus Folkways: The Role of Authority Approval in Intergroup Contact
Head: Ruth Katharina Ditlmann, Ph.D.
Cooperation with: Betsy Levy Paluck (Princeton University)
Robin Gomila (Princeton University)
Duration: ongoing
Funding: WZB

Naturalization of Immigrants: Obstacles and Opportunities in German Municipalities
Head: Ruth Katharina Ditlmann, Ph.D., Rafaela Dancygier, Ph.D. (Princeton University, USA)
Staff: Quinn Albaugh (Princeton University, USA)
Duration: 2015 - 2020 
Funding: University Center for Human Values and The Mamdouha S. Bobst Center for Peace and Justice at Princeton University

The Meaning of Being German, American, Singaporean: An Inductive Approach to National Identity.
Head: Ruth Katharina Ditlmann, Ph.D., Johannes Kopf-Beck (Max Planck Institut für Psychatrie, München); Valerie Purdie-Vaughns (Columbia University); Shirlena Huang (National University of Singapore); Eric Thompson (National University of Singapore)
Duration: 2012 - 
Funding: WZB, Columbia University and National University of Singapore

Ambassadors of Peace? Intergroup Contact and Conflict Resolution in Israel
Head: Ruth Katharina Ditlmann, Ph.D., Cyrus Samii (New York University, USA)
Duration: 2012 -
Funding: USAID, USIP (through New York University, USA)