This project investigates the structural complexity of human language and its significance for human nature. In particular, we look at possible relations between the ability to generate embedded structures and the cognitive ability of ascribing beliefs to others, which is called Theory of Mind. The project is funded by the European Commission and conducted by an multinational team from Britain (Tecumseh Fitch), The Netherlands (Angeliek van Hout), and Germany (Barbara Höhle, Manfred Krifka). The ZAS is the coordinating institution and conducts the semantic subproject. The project is completed, but publications from the project are still coming out.