Gustave Mark Gilbert (September 30, 1911 – February 6, 1977) was an American psychologist best known for his writings containing observations of high-ranking Nazi leaders during the Nuremberg trials. His 1950 book The Psychology of Dictatorship was an attempt to profile the Nazi German dictator Adolf Hitler using as reference the testimonials of Hitler's closest generals and commanders. Gilbert's published work is still a subject of study in many universities and colleges, especially in the field of psychology. [source](https://en.wikipedia.org/wiki/Gustave_Gilbert)