IQ Classifications AssessmentPsychology.com > Assessment > IQ Scores > IQ Classification IQ Classifications in Educational Use Wechsler, David. Wechsler Adult Intelligence Scale-Third edition

Psychological Corporation, 1997 Classification IQ Score Percent Included Theoretical Normal Curve Actual Sample Very Superior 130 and above 2.2 2.1 Superior 120-129 6.7 8.3 High Average* 110-119 16.1 16.1 Average 90-109 50.0 50.3 Low Average* 80-89 16.1 14.8 Borderline 70-79 6.7 6.5 Extremely Low* ** 69 and below 2.2 1.9 *The terms High Average, Low Average and Extremely Low correspond to the terms Bright Normal, Dull Normal and Mental Defective, respectively, used in the 1955 WAIS manual. **The term Extremely Low is used in place of the terms Mentally Retarded, used in the WAIS-R, and Intellectually Deficient, used in the WISC-III to avoid the implication that a very low IQ score is sufficient evidence by itself for the classification of "mental retardation" or "intellectually deficient."

IQ Classifications in Psychiatric Use Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)

American Psychiatric Association, 1994 V62.89 Borderline Intellectual Functioning IQ 71-84 317 Mild Mental Retardation IQ 50-55 to approximately 70 318.0 Moderate Retardation IQ 35-40 to 50-55 318.1 Severe Mental Retardation IQ 20-25 to 35-40 318.2 Profound Mental Retardation IQ below 20 or 25 The terms Educable Mentally Retarded and Trainable Mentally Retarded used in special education are roughly equivalent to DSM classifications for mild and moderate mental retardation, respectively. The DSM diagnostic criteria further require an assessment and determination of impairment in adaptive functioning in order to make a diagnosis of mental retardation.

IQ Classifications No Longer in Use Terman, Lewis M. The Measurement of Intelligence. Houghton Mifflin Company, 1916 An explanation of and complete guide for the use of the Stanford Revision

and extension of the Binet-Simon Intelligence Scale 140 and over Genius or near genius 120-140 Very superior intelligence 110-120 Superior intelligence 90-110 Normal or average intelligence 80-90 Dullness 70-80 Borderline deficiency Below 70 Definite feeble-mindedness Mental deficiency used to be divided into the following sub-classifications, but these labels began to be abused by the public and are now largely obsolete: Borderline Deficiency (IQ 70-80), Moron (IQ 50-69), Imbecile (IQ 20-49) and Idiot (below 20). Mental deficiency is now generally called mental retardation.