In the adjudication of cases involving alleged intellectual disability, accurate information
pertaining to the claimant's daily activities and current behavior is required in
order to determine the level of impairment severity. In instances of severe intellectual
disability, such information may preclude the need for standardized test results altogether.
Standardized test results are not required in cases of intellectual disability which
unequivocally meet or equal Listing 12.05A or 112.05A. intellectual disability must
be manifested by severe mental and social incapacity as evidenced by marked dependence
upon others for personal needs (e.g., toileting, eating, dressing, or bathing) and
inability to follow directions such that the use of standardized measures of intellectual
functioning is precluded. Standardized intelligence test results are essential to
the adjudication of all other cases of alleged intellectual disability.
The specific test administered should be reliable (yield repeatable results), valid
(be an accurate measure of what is meant by intellectual ability or intelligence),
and be standardized according to accepted psychometric practice and have normative
data relating to a recent cross-section of the general population. It is also necessary
for the particular test to sample a wide range of the subject's skills and abilities
rather than being limited to measuring only one or a few narrow intellectual functions.
Tests markedly deficient in one or more of the foregoing qualities should be avoided
for purposes of evaluating disability.
Moreover, it should be clearly understood that different tests may not yield identical
(or even similar) “IQ” results. The IQ requirements denoting a disabling impairment under the Listing of
Impairments are meant for application in conjunction with tests of general intelligence
having IQ means of approximately 100 and standard deviations of approximately 15 in
the general population at large (e.g., the Wechsler series (WAIS-R, WAIS-III, WISC-R,
WISC-III, WPPSI, and WPPSI-R and the revised Stanford-Binet scales.)
Stanford-Binet IV is preferred over the earlier LM edition because of the
updated and enlarged normative sample.
Thus, IQ's below 60 would reflect a level of intellectual functioning below that of
99.5 percent of the general population. IQ results of tests with parameters other
than the above would obviously require special transformation in order to render them
comparable to the requirements stated in the Listings.
If a file contains the results of several versions of the same test, such factor as
currency of the evaluation, claimant's age at time of evaluation, adequacy of claimant
and evaluator motivation, and completeness of the administration and report must also
be weighed in the decision as to which of several IQ's from different revisions of
the same measure will be determinative.
It is obviously important to know what test was administered, the date the test was
administered, the age of the subject at the time the test was given, whether the results
are applicable to the subject's current condition, and the qualifications of the examiner.
Adequate resolution of the issues posed by specific cases may require professional
consultation with a clinical psychologist or psychiatrist trained in intelligence
test administration and interpretation. At the hearing level, the testimony of a medical
or psychological advisor or vocational expert may be required.
Inclusion of subtest scores in conjunction with the Wechsler scales is always desirable
in the assessment of mental deficiency because it:
Provides evidence that the entire battery of subtests was administered rather than
a less reliable “short-form;”
Provides clues to a possible invalidity of test results or to possible errors in computing
IQ scores; and
Permits the evaluation of intellectual strengths and weakness that may have a bearing
on capacity to work where a determination cannot be made on the basis of medical considerations
Moreover, reporting of subtest scores is essential in cases where cognitive deficits
require assessment (e.g., chronic brain syndrome or “organicity” due to injury or disease). Since the pattern of subtest scores is most useful in
providing medical evidence (signs and laboratory findings) regarding such alleged
deficits, inclusion of subtest scores in such cases is required.
The absence of subtest scores in reports of psychological testing performed independently
of social security disability evaluation does not necessarily mean that a proper determination
or decision cannot be made without them. However, since it cannot be reliably determined
in advance when subtest scores will be required in connection with intellectual evaluation,
subtest scores should be requested when arranging to purchase consultative psychological
examinations involving the Wechsler scales. In the occasional situation where administration
of certain tests, subtests, or subscales may be neither feasible nor valid because
of the individual’s background, condition, or circumstances, it should be requested
that an explanation for this limitation be included in the report. If test results
(including subtest scores) are not included they should be requested, and if unavailable,
further testing may be required.
Test results obtained at younger ages are less reliable and valid than test results
obtained at older ages. Results obtained below the age of 6 are particularly suspect.
The test results should be consistent with the child's behavior and daily activities
as reflected in the evidence of record, including reports of disability interviews
or observations or testimony at the hearing. When there are inconsistencies further
documentation may be required to resolve these differences. While there is obviously
no specific age at which test results suddenly become “valid” (i.e., accurate and stable indices of the subject's abilities), IQ's obtained from
tests having the desirable qualities described above tend to stabilize by the age