Don't mention the potty training

This article in the Atlantic on the (modern) history of potty training notes that Freud's elaborate theorising on the "anal phase" led to some fairly unusual wartime theories:

American anthropologists turned to potty training in the early 1940s, while studying what they believed to be the particular aggressiveness of Japanese soldiers. Could this aggression, asked noted scholars like Margaret Mead, be caused by premature toilet training? Anthropologist Geoffrey Gorer thought so. He argued (as it turns out, falsely) that Japanese parents potty train their babies earlier than Western parents do—and that this accounted for “the overwhelming brutality and sadism of the Japanese at war.” Gorer’s reasoning was that premature toilet training forced Japanese babies to control their sphincters before important muscular development had taken place. This caused intense rage, which the infants soon repressed. This repression, in turn, gave rise to severe and compulsive personalities.

Some of this psychoanalysis was done in the service of the American war effort. In the early 40’s, Geoffrey Gorer and some of his like-minded colleagues were hired as analysts by the U.S. Office of War Information’s Foreign Morale Analysis Division. There, they attempted to build basic personality profiles of foreign nation-states. (In a related project, Gorer linked infant swaddling in Russia to manic-depressive personality disorders.) Gorer’s research on Japan would expand, but he always insisted: “Early and severe toilet training is the most important single influence in the formation of the adult Japanese character.”

This raises the crucial question:  at what age would Hitler have been potty trained?