Hugo Münsterberg (June 1, 1863 – December 19, 1916) was a German-American psychologist. He was one of the pioneers in applied psychology, extending his research and theories to Industrial / Organizational (I/O), legal, medical, clinical, educational and business settings. Münsterberg encountered immense turmoil with the outbreak of the First World War. Torn between his loyalty to America and his homeland, he often defended Germany's actions, attracting criticism. Hugo Münsterberg was born in Danzig (now Gdansk, Poland). His father Moritz was a merchant who bought lumber from Russia and sold it to England. His mother Anna was an artist who continued working while taking care of their four sons. Münsterberg’s first years of school were spent at the Gymnasium of Danzig where he graduated in 1882. He joined the University of Leipzig in 1883 where he met Wilhelm Wundt who influenced him to join the Psychology laboratory. He received a Ph.D. in psychology and in 1887 received his medical degree at Heidelberg. He also passed an examination that enabled him to lecture as a privatdocent at Freiburg. In the same year he married Selma Oppler of Strassburg on August 7. In 1891, he was promoted to assistant professorship and attended the First International Congress of psychology where he met William James. They kept correspondence and in 1892 William invited him to Harvard for a three year term as a chair of the psychology lab. In 1895 he returned to Freiburg due to uncertainties of settling in America. However, in 1897 he returned to Harvard in response to urgent invitation from James and Harvard’s president. In 1898 he was elected President of the American Psychological Association (APA) and in 1910 he was appointed exchange Professor from Harvard to the University of Berlin. He remained at Harvard until his sudden death in 1916 while on a lecture platform. Münsterberg was grounded on the theory of psychophysical parallelism which argued that all physical processes had a parallel brain process. He believed that certain mental ( Neurological ) illnesses have a cellular-metabolic causation and diagnosed based on his behavior-istic observations of the subject's reactions to interviews of them by him . " Psychotherapy " , the book he authored in regard to his investigations in matters of the mind , was published inclusive to 1909 . Hugo Münsterberg wrote several papers on the application of psychological information in legal situations. The main objective in most of these articles was eyewitness testimony which examined the witness. In 1908, he published his controversial book, On the Witness Stand (1908), which talked about psychological factors that can affect a trial’s outcome. Münsterberg was an admirer of Frederick Winslow Taylor. He wrote to him in 1913: “Our aim is to sketch the outlines of a new science, which is to intermediate between the modern laboratory psychology and the problem of economics.” Industrial psychology was to be “independent of economic opinions and debatable . . . interests.”[1] Both Dudley Andrew and James Monaco count Münsterberg's book "The Photoplay: A psychological study" as one of the early examples of film theory.