Mental Retardation IQ

During the 19th and early 20th century what we now call “mild” retardation was not recognized except as associated with disturbed or delinquent behavior. There was no simple way of diagnosing the more mild or incipient forms of mental retardation until the development of psycho-metrics around 1910. Then the “IQ” rapidly became a universal means, not only of identifying a mental deficiency but also of measuring its severity.

In 1910, new techniques in the public schools discovered there were ten times as many feeble-minded as anyone had suspected, and promptly coined the term “moron” to cover them! Thus, a psycho-metric definition of retardation came into being.