Second World War (1939-1945). The Second World War had two main effects on the development of psychology. Firstly, a diaspora of Jewish intellectuals from Europe arrived in Great Britain and the United States, and secondly, psychological research was funded, and used extensively during the war.\n\n1. The diaspora. The diaspora refers to the scattering of Jewish people around the world before, during and following the Second World War. This scattering of intellectuals had a pronounced effect, not because of the psychologists who fled, but also because of the many US or UK psychologists who came into contact with many new ideas for the first time. This included not only fellow psychologists, but also philosophers, linguists and novelists.
As well as the Jewish diaspora, a large number of gentile intellectuals also left Germany and mainland Europe before and during the war, often for New York or London, where they interacted and greatly influenced the existing scholars. According to Peter Robinson, who edited a volume of essays dedicated to Henri Tajfel “…it is thanks to the émigrés of Henri's generation that the field gained a foothold in the academic world” (Robinson, 1996, p. xi). 2. Applications of psychology. Unlike the First World War, when the application of psychology began only towards the end, psychology was used almost immediately from the beginning of World War II. Also, unlike World War I, where most psychological input was in the selection of recruits or treatment of 'shell shock', during World War II psychologists contributed in a variety of different areas. For instance, psychologists worked on:
• Personality psychometrics – Psychologists devised tests used for the selection of 'officer material' and in the main combatant forces. In the UK, the War Office Selection Boards were set up in 1942 for this purpose, and by 1945 some 100,000 applicants for officer rank had been psychometrically tested. Also, during the war factor analytic techniques first applied on a mass scale – for instance, H.J. Eysenck studied 700 patients at the Mill Hill Emergency Hospital during the war. This research was the basis for his subsequent theory of personality.
• Psychiatric disabilities of war – For instance, work at the Tavistock Clinic on Post Traumatic Stress Disorder and Psychoanalytic theories.
• Attitude research - large research programs on attitude change and persuasion were funded by the American Army during the war. Related research on leadership and group behaviour was also extensively funded during this period.
• Interaction with equipment – World War II was unique in its reliance on human operation of new technology, in areas as diverse as air traffic control, radar or code breaking. This led to psychological research into topics such as vigilance, training, stress and decision making. During this time, some old concepts (e.g. attention) were investigated with new vigour, while new concepts (e.g. stress) were developed as explanatory concepts.
• The rapid development of neuropsychology in the 1950s was very much based on studies of combat victim's head wounds and their subsequent psychological functioning.