mental deficiency

Alcoholism in the parents is frequently the cause of mental deficiency.

One form, easily recognized, is what is commonly called "mental deficiency."

Even if the patient recovers, whether as the result of operation or not, deaf-mutism or mental deficiency frequently occurs.

We know now that, short of real mental deficiency, there is or ought to be no such personage as the dunce.

A study of the hereditary transmission of mental deficiency in one family.