Looking back in the history of industrial and organisation (I/O) psychology, World War I and testing within the Army shows the early beginning of this field.
Robert Yerkes is given the most credit for developing the Army Alpha test along with others within the early years of the I/O field, and it was based off of intelligence tests created by Alfred Binet. The main idea was to determine the intellectual and emotional function of the soldiers since those with the highest intellect could in theory assure more victories.
Men were put into differently-sized groups and given tests to determine their intelligence level. The results were then reviewed to understand the soldiers' capacity of serving, and used to classify them for a job and evaluate their potential for a leadership position.
Since there were many in the Army who were illiterate or did not speak English, they took the Army Beta test. The additional functions of testing were to find those who were not mentally suited to serve, and to find those who possessed special talents to be used in specific jobs.
Walter Dill Scott assisted with classification and placement, and was instrumental in developing the duties and qualifications for more than five hundred jobs. New recruits, existing recruits and officer candidates were all tested to determine their abilities.
With the embracement of I/O psychology during wartime, the field was able to grow exponentially. Studies conducted during this time also led to the publication of the Journal of Applied Psychology in 1917.
Early articles written made reference to the science of psychology being used in the realm of business, with theories of psychology being used for advertising and to solve vocational selection.
This early Army testing was considered to be the way to assess the mental skills of soldiers and is the background of what is now called the Armed Services Vocational Aptitude Battery test, or ASVAB. Today, it is used for military testing for all branches of service and can be seen as the basis for all other types of occupational testing.