IQ Isn't Set In Stone, Suggests Study That Finds Big Jumps, Dips in Teens

"For as long as there's been an IQ test, there's been controversy over what it measures. Do IQ scores capture a person's intellectual capacity, which supposedly remains stable over time? Or is the Intelligent Quotient exam really an achievement test — similar to the S.A.T. — that's subject to fluctuations in scores?"

"The findings of a new study add evidence to the latter theory: IQ seems to be a gauge of acquired knowledge that progresses in fits and starts."

"In this week's journal Nature, researchers at University College London report documenting significant fluctuations in the IQs of a group of British teenagers. The researchers tested 33 healthy adolescents between the ages of 12 and 16 years. They repeated the tests four years later and found that some teens improved their scores by as much as 20 points on the standardized IQ scale."