I am a Junior Professor in the area of Corporate Development and Business Ethics at the University of Cologne since May 2015.

My current research is mostly focused on group behavior in a variety of contexts. I am interested in the effect of group identity, mob formation, dilution of morality via groups and group decision-making.

I am always happy to discuss new research ideas. Please contact me at: gonul2517(at)gmaildotcom


  • Are strangers just enemies you have not yet met? Group homogeneity, not intergroup relations, shapes ingroup bias in three natural groups” with L. Glowacki and H. Rusch. Accepted. Philosophical Transactions B.

    • Former title: “Ingroup love drives ingroup bias within natural groups”

  • “Lying in a foreign language?” with D. Alempaki and Y. Yang. (supercedes “When in Rome: Lying in a foreign language”) 2021. Journal of Economic Behavior and Organization. Final version here. Journal article here.

  • “Friend or foe? Social ties in bribery and corruption” with J. D. Zheng and A. Schram. 2021. Experimental Economics. Final version here. Journal article here.

  • “Deception and reciprocity” with D. Alempaki and S. Saccardo. 2019. Experimental Economics, 22(4), 980-1001. Open access journal article here.

  • “How to choose your victim” with K. Abbink. 2019. Games and Economic Behavior, 113:482-496. Final version: August 2018. Journal article here.

  • “Collusion in a buyer-seller network formation game”. 2018. Journal of Economic Behavior and Organization, 155:445-457. Full-text here.

  • “Spoils division rules shape aggression between natural groups” with L. Glowacki and H. Rusch. 2018. Nature Human Behaviour, 2(5): 322-326. Full-text here.

  • “The effect of link costs on simple buyer-seller networks” with M. van Assen and J. Potters. 2013. Games and Economic Behavior, 77(1): 229-246.

  • “Testing models of pure exchange” with M. van Assen. 2009. Journal of Mathematical Sociology, 33: 97-128.

  • “The stability of exchange networks” with M. van Assen, A. van de Rijt, and V. Buskens. 2009. Social Networks, 31: 118-125.

Working Papers

  • “Social groups with selfish individuals” (this version: May 2020)

  • “Pyramid schemes” with K. Kalaycı and P. Man (December 2021)

  • Sleepy paper: “Lying to be fair” with R. Roggema (this version: September 2015)

Work in progress

Social exclusion

  • Does social exclusion affect task performance, if so, is it through the information it conveys or psychological costs?

Learning in groups (with L. Wenner)

  • What is learned easier: prosocial or selfish behaviour? And from whom: own group or the population?

Group image concerns (with A. Apffelstaedt and F. Hoffmann)

  • Does group image concerns exist and how do they compare to individuals' social image concerns?

Media bias and populist preferences (with L. Strang)