AAMR changed its definition in 1973, partly in response to concern about the inappropriate overidentification of minority students as mentally retarded. The new definition eliminated the classification of borderline retardation, and changed the upper criterion of scores on intelligence measures from 85 to 70 or below (Grossman, 1973). The result was a significant reduction in the numbers of children eligible for special school services and governmental supports.

In 1973, the IQ cutoff was again changed back to 2 standard deviations below the mean; however, the benchmark of a measurable impairment in adaptive behavior was retained and given greater attention. Thus, given the IQ guideline for intellectual disability of 2 standard deviations below the mean, a person with an IQ below 70 would be considered intellectually disabled if an impairment in adaptive skills was also present. Raising the IQ guideline to 1 standard deviation below the mean, as was done in 1959, could potentially increase the number students qualifying as intellectually disabled from 2.5% to 16%, depending on the concomitant impairment in adaptive skills.

Significantly subaverage intellectual functioning is defined as approximately IQ 70 or below. ... Of intelligence in terms of intelligence testing was changed from the traditional one of "about 70 IQ" to one standard deviation below the mean of the test, which was approximately 85 IQ on the most commonly used tests; this change made it possible to include almost ... ... Terminology and Classification decided to abolish the cut-off score of one standard deviation below the mean (Borderline) and return to the more traditional cut-off point, which was approximately two standard deviations below the mean for the test used. The 1973 manual was different in a number of other ways, for it built upon experience with the earlier manuals. ... Significantly subaverage is defined as IQ of 70 or below on standardized measures of intelligence. This upper limit is intended as a guideline; it could be extended upward through IQ 75 or more, depending on the reliability of the intelligence test.

"In 1973 an AAMR committee again revised the definition. The committee constructed this revision with criticism of the 1961 definition in mind. It specified that significantly subaverage general intellectual functioning was to be determined by a score of at least two standard deviations below the mean on an intelligence test (Grossman, 1973). This meant that the cutoff point for mental retardation was essentially moved downward from 85 to 70. This change lowered the percentage of the population that might be diagnosed as mentally retarded." The article further notes that the revision was incorporated into the Education for All Handicapped Children Act of 1975 and emphasizes adaptive behavior and developmental period, with no reference to race or African American score distributions as a motivation.

In 1973, the American Association on Mental Deficiency changed its definition of mental retardation as: "Mental retardation refers to significantly sub-average general intellectual functioning existing concurrently with deficits in adaptive behavior, and manifested during the development period." (Grossman, 1977) The AAMD also decided that the cut off for being labeled "mentally retarded" would be 70 on the IQ test. Generally, this meant that only 2.25% of the population would be labeled instead of 16%. The main reasons for dropping the borderline category were its racial implications (racial minority groups were over-represented in the borderline group) and a growing uneasiness about the effects of labeling.

The bell curve for whites is centred roughly around IQ 100; the bell curve for American blacks roughly around 85.[3] African American IQ scores have long averaged about 15 points below those of Whites, with correspondingly lower scores on academic achievement tests.[3] These discussions of average group differences describe distributions; they do not state that ‘more than half of African Americans scored below IQ 85’ as a formal diagnostic criterion, nor do they connect such statistics to official changes in AAMR diagnostic cutoffs.

Prior to 1973, the recommended IQ cut-off score for mental retardation was 85. In 1973, that was revised downwards to approximately 70, where it remains today. This is roughly the lowest scoring 2% of the population.

In 1959, the American Association on Mental Deficiency set 85 as the I.Q. below which a person was considered to be retarded. In 1992, the renamed American Association on Mental Retardation lowered the mental retardation "ceiling" to an I.Q. of 70-75, but many mental health specialists argue that people with I.Q.s of up to 80 may also have mental retardation. With the upper ceiling on mental retardation reduced from an I.Q. of 85 to an I.Q. of 70, far fewer Americans are today diagnosed as "mentally retarded" than before. Although the lower I.Q. ceiling for mental retardation was agreed upon in part to avoid applying stigmatizing labels to so many people whose intelligence was below average, the changed I.Q. ceiling ironically had the effect of cutting off from social services such as special education many people who would have otherwise benefited from the extra support.

For the moment, take it on faith that the relevant black/white IQ gap is less than 15 points.[1] Between 1973 and 1985, black IQ (normed on whites) goes from 84 to 93, a huge gain.[1] Our analysis of standardization samples showed black IQ (age 12) rising from 85 in 1972 to 90.5 in 2002.[1] This Brookings paper discusses average black IQ around the mid‑80s in the early 1970s but does not claim that ‘more than half of African Americans scored below IQ 85’ nor that any AAMR diagnostic changes were based on such a statistic.

The average IQ for East Asians centers around 106; that for Whites, about 100; and that for Blacks, about 85 in the United States and 70 in sub-Saharan Africa.[4] The mean Black–White IQ difference in the United States of 85 versus 100 can be, and has been, explained both by the hereditarian model and by the culture-only model.[4] This review article characterizes the U.S. Black mean IQ as 85 but does not state that a majority of Black Americans score below 85 or link any diagnostic threshold changes in 1973 to that premise.

The drop in IQ score from 85 to 70 meant a shift that would require an individual to score 2 SDs below the mean on an IQ test to be within the MR Range. Approximately 2% of the population would obtain an IQ of 70 or less. Increased pressure to acknowledge the rights of children with disabilities to have a free and appropriate education resulted in the passing of Public Law 94-142 in 1975, which supported the AAMR initiatives to include children with disabilities in public schools. In special education led to changes in the criteria for MR, lowering the IQ to 70 from 85 (Grossman, 1973).

This material, summarizing legal standards, recounts the clinical criteria: "In the DSM, a diagnosis of mental retardation requires an IQ of 'approximately 70 or below' as well as deficits in two areas of adaptive functioning." It notes that many statutes and definitions follow DSM or AAMR criteria and that significantly subaverage intellectual functioning is defined as two standard deviations below the mean. The document does not connect the IQ threshold to any racial rationale; it presents the cutoff as derived from psychometric norms and clinical consensus.

African Americans score lower than European Americans on vocabulary, reading, and math tests, as well as on tests that claim to measure scholastic aptitude and intelligence.[2] It has narrowed since 1970, but the typical American black still scores below 75 percent of American whites on almost every standardized test.[2] This policy article discusses test-score gaps descriptively and does not assert that ‘over half of African Americans scored below IQ 85’ as a formal statistic or that AAMR changed diagnostic cutoffs for mental retardation because of that claim.

1973 AAMR definition: "Significantly subaverage general intellectual functioning existing concurrently with deficits in adaptive behavior, and manifested during the developmental period." Emphasis on "significantly subaverage" based on IQ scores that fall at least two standard deviations below the norm. Expanded the concept of adaptive skills to include standards of personal independence and social responsibility within the context of the person’s age and sociocultural group. Emphasis on reducing the number of students identified with mental retardation based solely on their IQ score.

The current AAIDD description reflects the legacy of earlier definitions: "One way to measure intellectual functioning is an IQ test. Generally, an IQ test score of around 70 or as high as 75 indicates a significant limitation in intellectual functioning." AAIDD defines intellectual disability as significant limitations in both intellectual functioning and adaptive behavior originating before age 22. This page, representing the successor organization to AAMR/AAMD, describes the threshold as a psychometric guideline tied to two standard deviations below the mean, without attributing the historical choice of cutoff scores to the distribution of scores in specific racial groups.

AFRICAN AMERICANS currently score lower than European Americans on vocabulary, reading, and mathematics tests, as well as on tests that claim to measure scholastic aptitude and intelligence.[5] It has narrowed since 1970, but the typical American black still scores below 75 percent of American whites on most standardized tests.[5] On some tests the typical American black scores below more than 85 percent of whites.[5] This book excerpt addresses black–white test score gaps; it does not describe AAMR diagnostic standards or claim that more than half of African Americans score below a specific IQ cutoff used for mental retardation.

AAMR changed its definition in 1973, partly in response to concern about the inappropriate overidentification of minority students as mentally retarded. The new definition eliminated the classification of borderline retardation, and changed the upper criterion of scores on intelligence measures from 85 to 70 or below (Grossman, 1973).

Children with intellectual disability typically have an intelligence quotient (IQ) below 70 and deficits in at least two adaptive behaviors that affect everyday living. ... Current tests are scored in "deviation IQ" form, with a performance level by a test-taker two standard deviations below the median score for the test-takers age group defined as IQ 70. Until the most recent revision of diagnostic standards, an IQ of 70 or below was a primary factor for intellectual disability diagnosis, and IQ scores were used to categorize degrees of intellectual disability. ... Historically, professional organizations such as the American Association on Mental Deficiency (later AAMR) played a central role in setting IQ guideline cutoffs, moving from about 85 (1 SD below the mean) in mid-20th century definitions back to about 70 (2 SDs below the mean) in the 1973 revision.

Mental retardation or mental disability is a generalized disorder characterized by impaired cognitive functioning. The affected individuals with mental retardation have an IQ below 70 (between 50 and 70 = mild mental retardation; below 50 = moderate mental retardation).[7] Based on the normal-curve statistics of the distribution of IQ in the black population, about 16 percent fall below IQ seventy.[7] This secondary blog article reiterates the conventional cutoff of IQ < 70 for mental retardation and notes the expected proportion below 70 in the Black population; it does not report any historical use of IQ 85 as a diagnostic threshold or an AAMR change made due to a majority of African Americans scoring below 85.

This ProQuest record indicates the inclusion of the 1973 Grossman manual definition in Public Law: "The 1973 Grossman, H. J. (Ed.). (1973). Manual on terminology and classification in mental retardation definition of mental retardation included in PL ..." Although the full text is not visible here, the citation shows that the 1973 AAMR/AAMD definition—based on significantly subaverage general intellectual functioning (two SD below mean) and deficits in adaptive behavior—was adopted in federal special education law, indicating an institutional rationale focused on developmental disability criteria, rather than on racial test-score distributions.

For example, if prerise Blacks were 1.1 White standard deviations below Whites, this convention puts their IQ at 83.5.[8] Whenever we refer to IQ scores in this article, they are expressed relative to the White mean of 100.[8] This academic article quantifies Black mean IQ in the low‑80s on certain test norms but does not suggest that AAMR ever used 85 as a diagnostic cutoff or that changes in 1973 were made because over half of African Americans fell below that score.

This social media summary (non-primary) paraphrases historical changes in AAMR criteria: "Prior to the 1992 AAMR definition, which set the IQ threshold for mental retardation ... 1973 was IQ below 70, plus significant adaptive ..." While brief and not an authoritative source, it reflects a common understanding that the 1973 AAMR definition set the cutoff at IQ below 70 in combination with deficits in adaptive behavior. It does not mention African American scores as a motivating factor for that change.

The threshold for mental retardation used to be an IQ score of 85 until 1973, instead of 70. Discussion. Users debate historical reasons for the change, including references to overrepresentation of Black children in special education, but no authoritative citation is provided for the specific claim that "more than half of African Americans scored below 85" being the cause.

In 1959, the AAMD set the IQ threshold for mental retardation at ≤85. It was lowered to ≤70 in 1973 by the AAMR to curb overdiagnosis, reduce stigmatizing labels, and align with the traditional 2-standard-deviation cutoff. There is no credible historical evidence that the change was specifically because more than half of African Americans scored below 85; rather, professional publications from the period cite concerns about the size and heterogeneity of the "borderline" group and the social consequences of labeling many low-IQ individuals as mentally retarded.

The IQ for being retarded in the 50s was 85, but they lowered it to 70 because it would mean 52% of black people would be classified as retarded.[9] This is a social‑media claim presented without citation to primary diagnostic manuals or statistical studies. The post attributes the alleged change in cutoff to racial statistics but does not provide evidence from AAMR/AAIDD documents or contemporaneous professional sources that such a motivation or IQ‑85 standard ever existed.

It is a fact that, on average, Black Americans tend to score lower than White Americans on IQ tests.[6] From what I’m reading in that paper, the gap has shrunk by about 3–5 points from the 1970s to the early 2000s.[6] This discussion thread cites literature on the Black–White IQ gap but treats the ‘IQ 85’ figure as an approximate mean; it does not reference any AAMR decision in 1973 or claim that more than half of African Americans were below IQ 85 in a way that drove a change in diagnostic criteria.