📊 1961: New Classification Terms

In 1961, the American Association on Mental Deficiency (AAMD) published a new diagnostic and classification manual.

The organisation is now called the American Association on Intellectual and Developmental Disabilities (AAIDD).

The new classification replaced the older terms:

• Moron

• Imbecile

• Idiot

with four levels of mental retardation:

• Mild

• Moderate

• Severe

• Profound

A borderline category was also included.

These categories were based largely on IQ scores, together with considerations of a person's ability to function.

🧠 IQ and Classification

At the time, an IQ score was an important part of the classification process.

An average IQ was considered to be around 100.

The historical system included a borderline category for people whose IQ scores were below the average range.

However, IQ scores were not a complete measure of a person's abilities.

A person's everyday functioning, development and ability to manage daily life were also important considerations.

Why did the terminology change?

The change from “moron,” “imbecile” and “idiot” to levels such as mild, moderate, severe and profound was intended to create more standardised professional terminology.

The older words had increasingly become associated with stigma and insults.

However, the newer term “mental retardation” eventually developed similar problems.

The word “retarded” became widely used as a derogatory insult, leading to another major change in terminology.

This eventually contributed to the modern use of “intellectual disability.”

⚠️ Important historical point

It is important to remember that these classifications reflect the medical and social understanding of disability at that time.

Modern approaches do not rely on IQ alone.

Today, intellectual disability is assessed by considering both intellectual functioning and adaptive functioning, including conceptual, social and practical skills.

People should never be reduced to an IQ score or diagnostic label.