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.

Torn between his loyalty to the United States and his homeland, he often defended Germany's actions, attracting highly contrasting reactions.

Hugo Münsterberg was born into a merchant family in Danzig (now Gdansk, Poland), then a port city in West Prussia.

A neo-Renaissance villa in Detmold, Germany, that Oscar lived in from 1886 to 1896 has recently been renovated and opened as a cultural center.

[7] Münsterberg had many interests in his early years, including art, literature, poetry, foreign languages, music, and acting.

While at Freiburg he started a psychology laboratory and began publishing papers on a number of topics including attentional processes, memory, learning, and perception.

They kept up a frequent correspondence and in 1892, James invited him to Harvard for a three-year term as a chair of the psychology lab even though Münsterberg did not speak English at the time.

[2]: 349  The outspoken views of Münsterberg on the issues of the upcoming First World War raised storms of controversy about his ideals and position.

He appeared as probably the most eminent supporter of German policies in the United States and so was at the utmost bitterly condemned by the Triple Entente (a 1907 informal understanding among the Russian Empire, the French Third Republic, and the United Kingdom of Great Britain and Ireland) and their friends, but to the pro-Germans, he appeared almost an idol.

Fearing a patriotic response to overt support of the German Empire would undermine his own more covert approach, he condemned the forming of an alien party within the United States as "a crime against the spirit of true Americanism" and said that its results would reach far beyond the time of the war.

[2]: 647  While working as Wundt's research assistant, Münsterberg studied voluntary activities through introspection, but they disagreed on the fundamental principles.

"[2]: 348  Whereas for Münsterberg "the feeling of willful actions results from an awareness of covert behavior, or a readiness to act overtly, elicited by a situation.

In 1908, Münsterberg published his controversial book On the Witness Stand (1908), which is a collection of magazine articles previously published by him where he discusses the many different psychological factors that can change a trial's outcome and pointed the way for rational and scientific means for probing the facts claimed by human witnesses by the application of experimental psychology to the administration of law.

They go on thinking that their legal instinct and their common sense supplies them with all that is needed and somewhat more... Just in the line of the law it therefore seems necessary not to rely simply on the technical statements of scholarly treatises, but to carry the discussion in the most popular form possible before the wider tribunal of the general reader" cementing his position that while the lawyer, judge, and the jurymen are confident in their abilities, that with the use of experimental psychology he can show just how flawed their thinking can really be.

First he would show them a large sheet of white cardboard with a certain number of black dots on it spread in an irregular order.

He believed that certain mental (neurological) illnesses have a cellular-metabolic causation and diagnosed based on his behavioristic observations of the subject's reactions to interviews of them by him.

He defined psychotherapy as "the practice of treating the sick by influencing the mental life... perhaps with drugs and medicines, or with electricity or baths or diet.

His treatment, which he applied mainly to cases of alcoholism, drug addiction, phobia, and sexual dysfunction, was basically instilling in his patients the idea that they could expect to improve as a result of their efforts.

[2]: 349 Münsterberg was an admirer of Frederick Winslow Taylor to whom he wrote 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."

A mere interest for one or another subject in school is influenced by many accidental circumstances, by the personality of the teacher or the methods of instruction, by suggestions of the surroundings and by home traditions, and accordingly even such a preference gives rather a slight final indication of the individual mental qualities.

A member of the community would call a meeting of all the neighborhood boys who were to leave elementary school at the end of the year and discuss with them whether they had any reasonable plans for the future.

It was clear that the boys knew little of what they wanted to do or what would be expected of them in the real world, and the leader was able to give them, especially in one-one-one conversations, valuable advice.

[26] From this experience an office "opened in 1908, in which all Boston children at the time when they left school were to receive individual suggestions with reference to the most reasonable and best adjusted selection of a calling.

There is hardly any doubt that the remarkable success of this modest beginning was dependent upon the admirable personality of the late organizer, who recognized the individual features with unusual tact and acumen.

And finally, what he believed to be the most important point, "the methods had to be elaborated in such a way that the personal traits and dispositions might be discovered with much greater exactitude and with much richer detail than was possible through what a mere call on the vocational counselor could unveil.

"[28] Münsterberg believes that these early vocational counselors point towards the spirit of the modern tendency toward applied psychology, and that the goal can only be reached through exact, scientific, experimental research, "and that the mere naïve methods—for instance, the filling-out of questionnaires which may be quite useful in the first approach—cannot be sufficient for a real, persistent furtherance of economic life and of the masses who seek their vocations.

Though he firmly believed that women should receive where possible, a higher education, he felt that graduate studies were too difficult and demanding for them.

[7] Both Dudley Andrew and James Monaco count Münsterberg's book The Photoplay: A Psychological Study as one of the early examples of film theory.

Though he believed in God and life after death, Münsterberg was throughout his career a committed opponent of parapsychology: the field of study concerned with the investigation of paranormal and psychic phenomena.

[38] Some investigators were originally baffled how Palladino could move curtains from a distance when all the doors and windows in the séance room were closed.