In January 1938, Clarence Hagen, a young Harvard psychology student, sent numerous letters to prominent psychologists of the day asking them for their signatures and an accompanying photograph. It is unknown how many letters Hagen sent in total, but he received at least 30 autographs, which he placed in a small notebook that accompanied portraits of some of the psychologists torn from a textbook.
This collection of signatures was donated to the Center for the History of Psychology in September 2008 by William Adams. The signatures were originally put together in a small notebook with photographs of some of the psychologists represented.
From the guide to the Clarence Hagen collection of autographs, 1938, (Center for the History of Psychology)
