A new study finds that one-fifth of children can gain or lose as many as 20 points on IQ tests taken during their teenage years.
For the study, published this month in the journal Nature, British researchers tested 33 normal children, first between the ages of 12 and 16, and then again four years later, using both IQ tests and functional magnetic resonance imaging, which measures blood flow in the brain. They found that an average of more than one in five students showed dramatic fluctuations in IQ over the course of adolescence.
Likewise, increases in IQ corresponded with increases in the gray matter found in the parts of the brain linked to the skills measured by verbal or nonverbal IQ tests, the article says.
Study co-author Sue Ramsden of the Wellcome Trust Center of Neuroimaging at University College London, said the changes were not due to random variations in students mood or concentration. “The fact that those changes in measured IQ correlated with changes in brain structure in areas of the brain that are plausibly linked to the skills being tested indicates that the performance changes are genuine,” she wrote in an email.
A version of this article appeared in the October 26, 2011 edition of Education Week as IQ Changes