What is the IQ range described for mental retardation in the source material?

What is the IQ range described for mental retardation in the source material?

• A. 0-70
• B. 71-85
• C. 86-100
• D. 101-115

Answer: (A)

Intelligence test scores center around a mean of 100 with a standard deviation of 15, so about two standard deviations below the mean is 70. An IQ of 70 or below is the threshold commonly described for intellectual disability in the source material, reflecting scores that fall well below average and indicate significant cognitive limitations. The ranges 71-85 or higher reflect low-average to average or above-average functioning, not intellectual disability. (Note: diagnosis also considers adaptive functioning, not IQ alone.)

Intelligence test scores center around a mean of 100 with a standard deviation of 15, so about two standard deviations below the mean is 70. An IQ of 70 or below is the threshold commonly described for intellectual disability in the source material, reflecting scores that fall well below average and indicate significant cognitive limitations. The ranges 71-85 or higher reflect low-average to average or above-average functioning, not intellectual disability. (Note: diagnosis also considers adaptive functioning, not IQ alone.)