A CONVENIENT SELF-ADMINISTERING SCALE FOR MEASURING INTELLECTUAL IMPAIRMENT IN PSYCHOTICS

A quick, objective, self-administering scale for measuring intellectual impairment has been described. It requires but 20 minutes to give and 2 minutes to score, and is adapted to group, as well as individual use. It consists of a vocabulary and an abstract-thinking test which are used together. Impairment is measured in terms of the abstract-thinking deficit taken in relation to vocabulary level. For convenience, a special impairment index, the C. Q. ( conceptual quotient), is employed; it represents the ratio of the patient's abstract-thinking ability to that of the average normal individual at his vocabulary level.

The scale was standardized on over a thousand normals for whom I. Q.'s were available; mental-age equivalents were established for the vocabulary and abstract-thinking tests, as well as for the two tests combined. This method of standardization rendered [SEE GRAPH IN SOURCE PDF] FIG. 4.mGraph showing median C. Q.'s and interquartile ranges (middle 50 per cent of cases) for the private hospital diagnostic sub-groups. the scale useful as a measure of intelligence, as well as of intellectual impairment.

To test its efficacy the scale was given to several hundred mental patients from both private and state hospitals. Comparison of the [SEE FIG.5 IN SOURCE PDF] FIG.5.mGraph showing median C. Q.'s and interquartile ranges (middle 50 per cent of cases) for the state hospital diagnostic sub-groups. C. Q.'s thus obtained with those of normals yielded the following significant findings. (1) Only 5 per cent of the state hospital cases reached the median of the normals, while less than 1 per cent of the normals fell as low as the state hospital median. (2) The private hospital median fell midway between that of the normals and state hospital cases. Analysis by diagnostic groups showed the psychoneurotics and other non-psychotics to approach the normals, with the functional psychotics falling lower, and the organic psychotics lowest of all. This trend was both striking and consistent.

[SEE FIG.6 IN SOURCE PDF] FIG. 6.mPrivate and state hospital data combined. The dots represent midpoints between the private and state hospital median C. Q.'s

The evidence confirms the original tenets; the scale has been found useful in measuring intellectual impairment. It is best suited for work with relatively early cases of average or superior intelligence. It is not suited for use with markedly deteriorated cases, and its use with subnormals must await the establishment of further norms.