Robert Yerkes sitting at his desk in Reed Hall, Harvard University

In 1917-18 Robert Yerkes, a psychologist whose legacy has a terrible reputation,  began the army testing programme whilst leading a group of American psychologists into the process of selection and screening for recruitment. In 1917, after the US declared war on Germany and the military movements began advancing, he suddenly began feeling like psychology as a discipline was ‘lagging’ (Byford, 2014, pp. 51) This led him to believe that  it was his duty to do something useful for the country. Consecutively, he began testing intelligence on potential soldiers. “As a committed believer in the efficacy of the Alpha and Beta tests, he insisted that they both tapped into some underlying factor, ‘native intellectual ability’, or intelligence […] He was also convinced that performance on either test was unaffected by things like culture and educational opportunities, an issue that we will return to later” (Byford, 2014, pp. 55) In other words, Yerkes believed that both, the Alpha and Beta tests measured the same thing.

His motivation was to build stronger armies, yet, the process entailed the exclusion of what today society knows as vulnerable groups, and such discrimination was implicit in his concept of intelligence; which was based on the efficiency of war, rather than on the construction of society as a whole. In 1921, Yerkes concluded that the average intelligence of the US population was lower than previously thought. Moreover, he observed that performance scores revealed a clear hierarchy among people and groups (Byford, 2014, pp. 58). His biggest error was to allow prejudice and discrimination to define the interpretation of what he considered scientific data. When examining his personal, political, and ideological agenda; it can be seen that he preferred the theoretical frameworks that promoted the eugenics movement. He highlighted innate differences for those who were born superior, and those who were not. His psychological framework widened the inequality gap, and defined criteria that excluded people from disadvantaged backgrounds. Those who were seen as inferior (the poor and the foreign) were restricted.

His conclusions are interpreted as incongruous (Byford, 2014, p. 121) When narrating his experience as a psychologist during and after the first world war, he wrote: “The problem of publication was still further complicated by a sense of responsibility to two important agencies: the military establishment on the one hand and the science of psychology on the other. This dual obligation rendered the task of reporting psychological examining peculiarly difficult, and to it the remaining shortcomings of the report may fairly be ascribed. The report supplies, for the use alike of soldier and scientist, essential information concerning methods and results” (Yerkes, 1921).

On the very the United States entered WWI, he wrote a letter determining the position of psychologists in military affairs. He also later on wrote about the many military emergencies there were, and the increasing rates of psychological problems; therefore, psychological services were offered to government. Shortly afterwards, the examination of recruits began. “A plan for the examining of recruits, in which the function of the psychologist in dealing with intellectual deficiency and psychopathic tendencies, and his limitation, as an assistant of the military medical examiner, to the purely psychological aspects of the work” (Yerkes, 1921, p. 9) He actually used the word inclusion in some of his writings, and truly tried to understand diversity. Moreover, he advocated for the study of individual cognitive instead of group cognitivity. He could perceive that many people were using social engineering as a method for investigation, and he was concerned about this, to the point in which he actually began to ask people to reflect on this.

“The discovery dates from our declaration of war in April, 1917. Promptly American psychologists decided to try to increase military effectiveness by bringing their information, techniques, and insights to bear on problems of manpower. As personnel specialists and psychological examiners, they assisted with the appraisal of recruits by supplying descriptive measurements of mental alertness, adaptability, and trade or other skills. Thus they contributed to the data for intelligent military selection (acceptance or rejection), classification, assignment, and training […] The World War saw no developments of military psychology or other personnel services in any other country which were remotely comparable with what occurred in the United States of America. Germany, late in the war, tested certain psychological procedures for personnel selection, with favourable result; Canada concentrated on improvement of methods of military training and re-education; and England utilized her psychologists chiefly to supplement the labors of medical officers. Ours, because of superior professional resources and less acute risks from aggression, was an altogether unique opportunity for pioneering, the prompt improvement of which yielded signal successes […] It was inevitable that the idea of mental versus material warfare should seek and find place in this philosophy of war. First proposed as hypothesis that feelings, thoughts, and attitudes might be used as instruments of warfare, the idea soon was put to the test in the civil contest between democratic and Nazi ideologies. It is said that the Nazi leaders thus proved to their satisfaction the effectiveness of mental weapons […] Total war may be defined as the employment of all available material, mental, and spiritual resources to achieve national objectives. It is unannounced, timeless, spaceless. In warfare as thus conceived, psychology and its applications become as indispensable as are the physical sciences and their technologies […] Psychological problems of propaganda, morale, personality, analysis and appraisal, educational training, industrial efficiency, fatigue, and similar concerns of human engineering, occupy the staff” (Yerkes, 1941, p. 529-530)