After Erich Fromm received his Ph.D. in 1922 from the universities of Frankfurt and Heidelburg, he studied psychoanalysis at the University of Munich and at the Psychoanalytic Institute of Berlin. Associated with the Institute for Social Research from 1929 to 1932, Fromm was influenced by Marxist thought as well as by the work of Sigmund Freud, but he eventually broke with Freud, giving greater weight to the influence of social and economic forces on personality. Fromm came to the United States in 1934 during the rise of Nazism, and he served on the faculties of several universities, including Columbia and Yale, and also chaired the Department of Psychology at National Autonomous University of Mexico, Medical School, Frontera, Mexico. His 1941 work on totalitarianism, "Escape from Freedom", has become a classic, and "The Art of Loving" was a best-selling book in the 1960s. Fromm brought social thought to psychology, and sought to apply psychology so as to improve society.