The Mongol in Our Midst: A Study of Man and His Three Faces is the title of the pseudo-scientific book written by British physician Francis Graham Crookshank and published in 1924.
The book, characteristic of the consequently discredited ideas of scientific racism prevalent at the time, explored and presented the idea that "Mongolian imbecility" (a form of intellectual disability now called Down's syndrome and known to be caused by the replication (trisomy) of the chromosome 21) was an atavistic throwback to, and/or the result of, rape committed by members of the supposedly more primitive "Mongoloid races" (such as the Huns, Avars or the Mongols themselves) in the wake of their various invasions of Europe throughout history.
[1] In The Mongol in Our Midst, Crookshank argued that "Mongolian imbecility", thought at the time to affect only Caucasian people, was the result of the distant racial history of a person with the disorder.
[3][4] In support of his theory, Crookshank relied on a set of physical traits and behaviors he dubbed the "Mongolian stigmata", among which he included small earlobes, protruding anuses, and small genitals in both sexes,[5] all of which he claimed to be common among both "Mongolian imbeciles" and members of what he termed the "Mongoloid race", which included Chinese and Japanese people, as well as those from Mongolia.
Crookshank also cited the cross legged sitting posture of both some "Mongolian imbeciles" and some depictions of the Buddha in statues as further supporting evidence for his theory.