The psychologist and the bombardier: the Army Air Forces' aircrew classification program in WWII.

During World War II, psychologists in the Army Air Forces were given an unprecedented opportunity to showcase their discipline by developing examinations to test the aptitude of aviation cadets as pilots, navigators, or bombardiers. These psychologists enjoyed success in classifying pilots and navigators, but became quickly frustrated by their results for bombardiers. The trouble lay not in their choice of tests but in their performance measures for bombardiering, a difficulty that came to be known as 'the problem of the criterion.' This episode in the history of military mental testing exemplifies the challenges faced by psychologists at the moment they were poised to gain the support of the armed services, and highlights how these new hazards shaped postwar military psychology.