Competition and moral behavior: A meta-analysis of forty-five crowd-sourced experimental designs

Christoph Huber, Anna Dreber, Jürgen Huber, Magnus Johannesson, Michael Kirchler, Utz Weitzel, Miguel Abellán, Xeniya Adayeva, Fehime Ceren Ay, Kai Barron, Zachariah Berry, Werner Bönte, Katharina Brütt, Muhammed Bulutay, Pol Campos-Mercade, Eric Cardella, Maria Almudena Claassen, Gert Cornelissen, Ian G.J. Dawson, Joyce DelnoijElif E. Demiral, Eugen Dimant, Johannes Theodor Doerflinger, Malte Dold, Cécile Emery, Lenka Fiala, Susann Fiedler, Eleonora Freddi, Tilman Fries, Agata Gasiorowska, Ulrich Glogowsky, Paul M. Gorny, Jeremy David Gretton, Antonia Grohmann, Sebastian Hafenbrädl, Michel Handgraaf, Yaniv Hanoch, Einav Hart, Max Hennig, Stanton Hudja, Mandy Hütter, Kyle Hyndman, Konstantinos Ioannidis, Ozan Isler, Sabrina Jeworrek, Daniel Jolles, Marie Juanchich, Raghabendra K.C. Pratap, Menusch Khadjavi, Tamar Kugler, Shuwen Li, Brian Lucas, Vincent Mak, Mario Mechtel, Christoph Merkle, Ethan Andrew Meyers, Johanna Mollerstrom, Alexander Nesterov, Levent Neyse, Petra Nieken, Anne Marie Nussberger, Helena Palumbo, Kim Peters, Angelo Pirrone, Xiangdong Qin, Rima Maria Rahal, Holger Rau, Johannes Rincke, Piero Ronzani, Yefim Roth, Ali Seyhun Saral, Jan Schmitz, Florian Schneider, Arthur Schram, Simeon Schudy, Christiane Schwieren, Irene Scopelliti, Miroslav Sirota, Joep Sonnemans, Ivan Soraperra, Lisa Spantig, Maurice E. Schweitzer, Janina Steinmetz, Sigrid Suetens, Andriana Theodoropoulou, Diemo Urbig, Tobias Vorlaufer, Joschka Waibel, Daniel Woods, Ivo Steimanis, Ofir Yakobi, Onurcan Yilmaz, Tomasz Zaleskiewicz, Stefan Zeisberger, Felix Holzmeister

Research output: Contribution to journalArticlepeer-review


Does competition affect moral behavior? This fundamental question has been debated among leading scholars for centuries, and more recently, it has been tested in experimental studies yielding a body of rather inconclusive empirical evidence. A potential source of ambivalent empirical results on the same hypothesis is design heterogeneity—variation in true effect sizes across various reasonable experimental research protocols. To provide further evidence on whether competition affects moral behavior and to examine whether the generalizability of a single experimental study is jeopardized by design heterogeneity, we invited independent research teams to contribute experimental designs to a crowd-sourced project. In a large-scale online data collection, 18,123 experimental participants were randomly allocated to 45 randomly selected experimental designs out of 95 submitted designs. We find a small adverse effect of competition on moral behavior in a meta-analysis of the pooled data. The crowd-sourced design of our study allows for a clean identification and estimation of the variation in effect sizes above and beyond what could be expected due to sampling variance. We find substantial design heterogeneity—estimated to be about 1.6 times as large as the average standard error of effect size estimates of the 45 research designs—indicating that the informativeness and generalizability of results based on a single experimental design are limited. Drawing strong conclusions about the underlying hypotheses in the presence of substantive design heterogeneity requires moving toward much larger data collections on various experimental designs testing the same hypothesis.

Original languageEnglish
Article numbere2215572120
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number23
StatePublished - 6 Jun 2023

Bibliographical note

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Copyright © 2023 the Author(s).


  • competition
  • experimental design
  • generalizability
  • metascience
  • moral behavior

ASJC Scopus subject areas

  • General


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