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IQ's between 3 and 18 years of age were used to predict attained education and occupational status after 26 years of age. By the second grade these predictive correlations approached those that have been obtained with contemporaneous adult IQ's, especially for occupational status. However, they were not high enough for practical purposes requiring long-term prediction for individual normal children.
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Robert B. McCall (1977) studied this question.
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