By PT Staff, published on October 23, 2003 - last reviewed on February 26, 2009
Over the last century, there has been a steady rise in IQ scores.
Known as the Flynn Effect, IQ test makers counter this by periodically
increasing the difficulty of tests—IQ tests are rewritten so that the average score rests at 100 points. An unintended consequence is a
disproportionate growth in special education. Some children may now find themselves arbitrarily classified as mentally
Stephen Ceci, a professor of developmental psychology at Cornell
University, and colleagues analyzed IQ data on nearly 9,000
children in special education across the nation. The
survey was taken after a new—and more difficult—IQ test
A borderline or mildly retarded child lost, on average, 5.6 IQ points when he took an adjusted test. As a result, the number of children recommended for special education programs tripled five years after the IQ test was adjusted.
The authors note that the Flynn Effect may also have consequences in legal and other realms. An inmate, for example, might serve a life sentence in jail or he may be brought to death row depending on whether he is classified as mentally retarded or of borderline intelligence. And in the military, a recruit may be denied certain jobs based on IQ scores. "Caution should be used when basing important financial, social or legal decisions on IQ scores," Ceci notes.