Wilhelm Arnold studied psychology at the University of Munich before the war. He received his doctorate under Aloys Fischer and Richard Pauli in 1935.
After the war, Arnold habilitated at the University of Erlangen in 1948. In addition to his work at the university, he made a career in career counseling at the employment office in Nuremberg. He reached the position of consultant at the Federal Employment Agency for job placement and unemployment insurance. In 1953, Arnold, a proven representative of applied psychology, was appointed to Würzburg.