“The Historical Context of the Reorganization of the APA in 1945
The end of World War II saw a two fold interest in psychology. Many veterans had an interest in studying psychology. The GI Bill helped soldiers to finance the education in these fields. Concurrently, there was an increased demand in psychological services to veterans who returned to the United States.
Shortly after, in 1946, the National Institute for Mental Health was founded. Visit a history of the institute here. The creation of the institute furthered interest in psychological studies.
The first group of VA clinical psychology trainees completed their training. The VA had 109 general hospitals, 21 tuberculosis hospitals, 38 neuropsychiatric hospitals, and 63 mental hygiene clinics. The amount of locations and shared new test tools allowed for “cooperative study”. “In cooperative studies, a common research protocol was shared by as many hospitals as wished to collaborate. The advantages were a very large patient pool, huge data sets, and a fair amount of statistical power in the analysis. Like all large studies, there were problems, including some inconsistency in following the protocol. The first cooperative studies were among the tuberculosis hospitals.” (Pickren. (2003).)
The interest in the field of psychology and the need for practitioners caused a rapid growth in APA membership, from roughly 3700 in 1945 to about about 30,000 in 1970.