Mengele’s unethical research was part of existing beliefs, practice

Mengele’s background, the study of medicine and anthropology, was well suited to Nazi ideology.

Mengele’s unethical research was part of existing beliefs, practice - The Jerusalem Post (jpost.com)

"Like all doctors in 1930s Germany, Mengele came under Hitler’s concept of German medicine that departed from the traditional caregiving role, Marwell explains. The physician’s first responsibility was to the nation, not individual patients. As part of the Führer’s weltanschauung, doctors were “biological soldiers,” committed to ensuring Germany’s glorious destiny by “cleansing” the population of “inferior” genetic material: Jews, gypsies, the mentally ill, and the handicapped, among others. Hitler’s racial ideology violated the Hippocratic oath, as doctors enforced “eugenic” laws to foster “racial hygiene.” Medical professionals were empowered to take aggressive actions against those believed to menace the German people and the nation’s future. In this environment, a young Dr. Josef Mengele began practicing medicine."