PIs: Prof. Dr. Markus Knauff, PD Dr. Carsten Bäcker
Involved: L. Estefania Gazzo Castañeda
Institutions: Justus-Liebig-Universität Gießen, Christian-Albrechts-Universität zu Kiel

The project's starting point is to explore the issues of (1) relevance, (2) justification, and (3) rationality concepts, in an interdisciplinary research project that—for the first time—creates systematic links between the psychology of rationality, legal reasoning, and the philosophy of law. "Relevance" means the different premises, rules, or laws may have different grades of relevance for a legal decision. "Justification" means that a certain (criminal) act might be justified by the suspects' mistaken beliefs about what actually is the case or what is allowed or forbidden. "Rationality concepts" refers to the fact that in law theory several theories of legal rationality were proposed and that legal decisions are affected by these different concepts of rationality. The basic experimental paradigm resembles the belief revision problems from the psychology of reasoning. However, in our experiments the individuals are not forced to revise an existing belief. The additional information might modify an existing belief, but it can also be ignored, without risking (logical) inconsistency in the belief state. In other words, the revision is logically not necessary, but it might be rational because the new argument provides additional in-formation that can be relevant for the decision. In all experiments the participants will be (1) students with no legal knowledge, (2) law students (with legal knowledge but no professional experience), and (3) experienced judges and prosecutors. The experiments will be conducted in collaboration with the "Hessische Justizakademie" and the Oberlandesgericht Frankfurt (OLG). In the theoretical part of the project we will, on the one hand, construct specific legal problems that match with our research ques-tions and also have practical relevance for the theory and philosophy of law. On the other hand, we will utilize the experimental findings to make progress in the theory of legal reasoning.

Project-related Publications
Gazzo Castañeda, L. E., & Knauff, M. (im Druck). When will is not the same as should: The role of modals in reasoning with legal conditionals. The Quarterly Journal of Experimental Psychology.
More publications can be found on this page.

Relation to the SPP1516's second funding period
This project continues during the second funding period. Go to project page...