Early life and education
Mengele was born on 16 March 1911 to Karl and Walburga (née Hupfauer) Mengele in Günzburg, Bavaria, Germany. He was the oldest of three children; his two younger brothers were Karl Jr. and Alois. Their father was founder of the Karl Mengele & Sons company, producers of farm machinery. Josef was successful at school and developed an interest in music, art, and skiing. He completed high school in April 1930 and went on to study philosophy in Munich, where the headquarters of the Nazi Party were located. In 1931, Mengele joined the Stahlhelm, Bund der Frontsoldaten, a paramilitary organization that was absorbed into the Nazi Sturmabteilung (Storm Detachment; SA) in 1934.
In 1935, Mengele earned a PhD in anthropology from the University of Munich. In January 1937, he joined the Institute for Hereditary Biology and Racial Hygiene in Frankfurt, where he worked for Dr. Otmar Freiherr von Verschuer, a German geneticist with a particular interest in researching twins. As von Verschuer's assistant, Mengele focused on the genetic factors that result in a cleft lip and palate, or a cleft chin. His thesis on the subject earned him a cum laude doctorate in medicine (MD) from the University of Frankfurt in 1938. (Both of his degrees were revoked by the issuing universities in the 1960s.) In a letter of recommendation, von Verschuer praised Mengele's reliability and his ability to verbally present complex material in a clear manner. The American author Robert Jay Lifton notes that Mengele's published works were in keeping with the scientific mainstream of the time, and would probably have been viewed as valid scientific efforts even outside Nazi Germany.
On 28 July 1939, Mengele married Irene Schönbein, whom he had met while working as a medical resident in Leipzig. Their only son, Rolf, was born in 1944.