This dissertation is the result of research I have carried out at the Center for Adaptive Behavior and Cognition (ABC) of the Max Planck Institute for Human Development (MPI) as a fellow of the LIFE Research school.

First and foremost I would like to dearly thank my advisor Jörg Rieskamp for his time, unfailing support and outstanding mentoring throughout the last three years. I deeply appreciate that he was always there when I needed advice. Jörg’s unique ability to reduce a complex problem to a simple question and to combine scientific and methodological rigor with a pragmatic approach, encouraged me to search for simple solutions. Further, I would like to thank my colleagues and friends at the ABC Research group and in the LIFE Research School who with their warm atmosphere, critical minds, and helpful advice made my dissertation possible, and the last three years an exciting time. I’m deeply thankful to Gerd Gigerenzer for providing me the opportunity to work in this wonderful environment and Paul Baltes, and the LIFE directors for giving me the chance to enjoy the truly stimulating experience of being part of the LIFE program.

I’m very grateful to Peter Juslin, Linnea Karlsson, and Henrik Olsson for generously sharing their data with me, enabling me to include a reanalysis of their study in my dissertation. Further I’d like to thank Lael Schooler, Henrik Olsson, Konstantinos Katsikopoulos, Stefan Krauss, Peter Frensch, and Richard Gonzalez for their advice and comments on prior versions of the manuscripts. I also thank Jing Qian, Benjamin Scheibehenne, Rui Mata, Thorsten Pachur, Andreas Wilke, Wolfgang Gaißmeier, and Tim Johnson for their thought-provoking comments, interesting discussions, and most of all their friendship. Above all I want to thank Jutta Mata, for her friendship, patience, encouragement, invaluable help and advice on countless occasions throughout the last three years.

Further I would like to thank Gregor Caregnato and all the student assistants for their help and patience in collecting my data and developing the experimental programs; Christian Elsner for his technical as well as emotional support; Uwe Czienkowski for encouraging me to program the experiments myself and his help with any problems I encountered on the way and Anita Todd for her thorough editing of my manuscripts.

I thank my family and friends who gave me the strength to go forward and helped me find time to relax and enjoy life while working on my dissertation; my Nonna Ruth for her unfaltering belief in me; my brothers Thomas and Martin for being there, whenever I need them and my parents for their unconditional support. Their dedication to science, insatiable curiosity and questioning minds raised my interest in science and encouraged me to pursue an academic career.