IQ

 1961: A change in classification

 

The American Association on Mental Deficiency (AAMD) published its Manual on Terminology and Classification in Mental Retardation in 1961. The manual moved away from the older historical categories such as idiot, imbecile, and moron and toward a more standardized classification based substantially on intellectual functioning and adaptive behavior.

 

The 1961 system included:

 

Classification  Historical IQ range*

Borderline 68–83

Mild    52–67

Moderate 36–51

Severe      20–35

Profound   Below 20

 

*The precise ranges varied depending on the intelligence test being used. The classification was based heavily on IQ and was expressed in terms of standard deviations from the test mean.

 

Why this was an important change

 

The change shows how professional terminology was becoming more standardized and systematic.

 

Instead of describing someone with highly stigmatizing historical labels such as:

 

"idiot" → "imbecile" → "moron"

 

the classification moved toward terms describing levels of functioning.

 

However, it's important to remember that the terminology still differed greatly from today's language. The term mental retardation remained the professional term for many decades.

 

Another important development was the increasing recognition of adaptive behaviours in everyday life—rather than relying entirely on an IQ score. The 1961 AAMD manual incorporated adaptive behaviour into its terminology and classification.

 

The terminology continued to change

 

The process didn't stop in 1961.

 

1961:

Mental retardation + IQ-based categories + growing emphasis on adaptive behaviour

 

⬇️

 

1973:

The AAMD changed the definition to require significantly subaverage intellectual functioning and deficits in adaptive behavior and eliminated the borderline category.

 

⬇️

 

Later decades:

The field increasingly moved away from defining people primarily by IQ level and toward considering adaptive functioning, support needs, and the person's actual functioning in their environment.

 

⬇️

 

Today:

Intellectual disability is the preferred terminology. In the United States, federal law formally replaced mental retardation with intellectual disability through Rosa's Law (2010).

 

The bigger lesson for your module

 

This fits extremely well with your earlier section on the danger of labelling.

 

The history shows that changing terminology is not merely about finding a nicer word. It reflects changing ideas about:

 

What disability means

How people should be assessed

How much importance should be placed on IQ

The role of adaptive functioning

The person's support needs

How society views people with intellectual disabilities

 

And importantly, changing the label alone does not eliminate stigma. A new term can eventually acquire negative meanings if society continues to use it to stereotype or devalue people.

 

That is why modern disability practice places increasing emphasis on the individual, strengths, abilities, support needs, participation, and right-not simply a diagnostic label or IQ score.