IQ reference chart

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An example of a general IQ reference chart

I.Q. Range (15SD)	Intelligence Classification
25 - 40	Severe mental disability
40 - 55	Moderate mental disability
55 - 70	Mild mental disability
70 - 85	Borderline mental disability
85 - 115	Average
115 - 130	Above average
130 - 145	Moderately gifted
145 - 160	Highly gifted
160 - 175	Exceptionally gifted
Over 175	Profoundly gifted

IQ reference charts are tables suggested by psychologists to divide intelligence ranges into various categories.^[1][2] As reference charts, they are not to be taken as absolute or very precise. The reason for this is the lack of a uniform definition of intelligence and the current inability to wholly quantify it in a scientific manner. To get a "true" IQ score, multiple IQ tests must be taken since professionally administered IQ tests are only roughly 96% reliable.^[3] The average of multiple tests, usually at least three, is considered that person's "true" IQ score. However, these tests must be taken within a relatively short period of time, normally under one year for three or more tests.^{[citation needed]}

Contents 1 Terman Classification 2 Wechsler Classification 3 Mental deficiency 4 See also 5 References

[edit] Terman Classification

Lewis Terman, inventor of the Stanford-Binet intelligence test, later devised a classification based on gradations of 16 (Standard Deviation):^[4]

Terman's classification

I.Q. Range (16SD)	Intelligence Classification
164 and over	Genius or near genius
148 - 164	Very superior intelligence
132 - 148	Superior intelligence
116 - 132	Above average intelligence
84 - 116	Normal or average intelligence
68 - 84	Dullness
52 - 68	Borderline deficiency
Below 52	Definite feeble-mindedness

[edit] Wechsler Classification

David Wechsler, inventor of the Wechsler Adult Intelligence Scale, based his own classification on the probable error of IQ rather than the range.^[5]

Wechsler's classification

I.Q. Range (15SD)	Intelligence Classification	Percent Included
145 and over	Very superior	2.2
130 - 145	Superior	6.7
115 - 130	Bright normal	16.1
95 - 115	Average	50
80 - 95	Dull normal	16.1
65 - 80	Borderline	6.7
65 and below	Defective	2.2

[edit] Mental deficiency

The terms once used to classify mental deficiency are now considered simply terms of abuse:^[6]

Mental deficiency

I.Q. Range	Intelligence Classification
70 - 80	Borderline deficiency
50 - 69	Moron
20 - 49	Imbecile
Below 20	Idiot

Now mental retardation is classified differently:^[7]

Mental retardation

I.Q. Range	Intelligence Classification
50 - 69	Mild (educable)
35 - 49	Moderate (trainable)
20 - 34	Severe
Below 20	Profound

[edit] See also

• Intelligence quotient
• General intelligence factor

[edit] References

1. ^ Wechsler, D. (1944). The Measurement of Adult Intelligence. Baltimore: The Williams & Wilkins Company.
2. ^ Reber, A.S. (1995). The Penguin Dictionary of Psychology, 2nd ed. Toronto: Penguin Books.
3. ^ Wechsler Adult Intelligence Scale-Revised
4. ^ http://www.iqcomparisonsite.com/IQBasics.aspx
5. ^ Wechsler, D. (1944). The Measurement of Adult Intelligence. Baltimore: The Williams & Wilkins Company.
6. ^ Reber, A.S. (1995). The Penguin Dictionary of Psychology, 2nd ed. Toronto: Penguin Books.
7. ^ Reber, A.S. (1995). The Penguin Dictionary of Psychology, 2nd ed. Toronto: Penguin Books.