Giving children rewards for doing well on tests can significantly improve their scores on IQ tests, research by two psychologists indicates, and the effect is most dramatic for low-income black children and children assigned to special education classes. In giving IQ tests to children, the two Central Michigan University researchers and several of their graduate students in psychology found that motivation may be curcial to the successful performance of certain children on these tests. The psychologists said the findings are important in light of recent court cases which contend that IQ tests often mislabel black children as mentally impaired. They also note that IQ tests frequently are the main criteria for assigning children to special education classes. One of the psychologists, Carl Johnson, said the accepted way to administer IQ tests is to provide no verbal or tangible reinforcement for correct answers. "Psychologists who administer the test are specifically instructed to provide no reinforcement other than such neutral comments as 'Keep on working' or 'Good try,' "Johnson said. He and his colleagues said that in their research they divided their subjects into three groups: One took the tests as normally administered without reinforcement for the correct answers. Another section was given tokens for correct answers. The tokens later could be exchanged for coloring books, crayons, raisins, ribbons, pens, rings and toys.

The third group of students had to answer a specified number of questions correctly before they received any tokens. The researchers said immediate reinforcement improved the test scores significantly for all the children, but the most dramatic increases were with the black and special education children. In fact, the psychologists said half the children labeled as mildly retarded scored above the mentally impaired level when they had reinforcement. The researchers said they would administer more IQ tests to see the effects of reinforcement on children of different ethnic backgrounds, ages and socio-economic classes.