The intellectual correlates scale and the prediction of premorbid intelligence in brain-damaged adults

An attempt was made to determine if premorbid intelligence could be estimated in brain-damaged persons through the use of regression equations developed from a scale of items reflecting interests, attitudes, personal values, and personality characteristics that correlated with WAIS-R IQs. A total of 33 adults with no reported history of brain damage were used in the item selection study. The resulting scale, the Intellectual Correlates Scale (ICS), was then administered to 30 brain-damaged persons and a group 28 normal controls, none of whom participated in the item selection study. Comparisons between the ICS equations for estimating WAIS-RIQs and two sets of demographic equations were made. As expected, all estimates of Full-Scale IQs were higher than actual IQs for brain-damaged subjects, but no differences were found between estimated and actual Full-Scale scores for normals. Results for Verbal and Performance IQs were more complex. Semi-partial correlations were used to compare the ICS equations with the corresponding demographic equations to assess the unique contributions of each.