It would have been better if, after Leipzig University, I had gone to Berlin University, to learn more about configuration psychology, Gestaltpsychologie, pioneered by Max Wertheimer and developed by Köhler and Lewin in Berlin, and Koffk a at Smith College in the United States. But, as the object of my trip to Germany was not theoretical psychology but professional orientation, I went to the Psychology Institute of Hamburg University, headed by Professor William Stern, who, with Professor Otto Lippmann, were the main promoters of the psychological- exam-based professional orientation movement. Helmuth Bogen, head of the office for professional orientation in Berlin, author of the best treatise on this important issue of applied psychology, was also Stern's student.

Hamburg University was new, because it was set up at the end of World War I in the building of what had been the institute for colonial studies, serving the German colonial empire. Losing the colonies left it without activity. The chair and director of the institute, Professor Stern, came from the University of Breslau. Also there was Heinz Werner, an associate professor of evolutionary psychology. General psychology was handled by F. Heider, who was then professor at Smith College, where Koffka taught as well. Labor psychology in professional orientation was handled by assistants Rollof and Wunderlich. Stern's personality inspired everyone to enthusiasm, including the students. Krueger was courteous, but very protocol bound. However, Stern was the perfect conversationalist, not only in private but also in the classroom. Krueger and Köhler concentrated on general psychology. Stern granted the same importance to differential psychology, which he founded, as he did to evolutionary psychology, with Werner as his deputy. Stern also dealt with child psychology, which was also studied by Martha Muchow, an incredibly capable assistant. Social psychology proper, as well as mathematical psychology, was handled by P. R. Hofstätter, but only two decades later, when he came to head the institute. During Stern's tenure, the guiding spirit there was based on his personality-centered psychology and on the principle of freedom of thought, which was granted to everyone there. The tradition of this freedom of thinking was preserved by Professor Bondy, Stern's successor to the chair, and also nowadays, under Hofstätter.