IQ Changes in Teens
It was originally though that IQ could not change within an individual, and that the test would remain stable if education remained stable.
The Flynn Effect threw this thinking away. The Flynn Effect goes like this: an intelligence quotient (IQ) is standardized by using a sample of test-takers. The average of the results is set to 100 with a standard deviation set to 15 IQ points. When IQ tests are revised, they are standardized again, but use a new sample of test-takers, born more recently than the first. Again, the average is set to 100. However, when the new test subjects take the older tests, in almost every case their average scores are significantly above 100.
The Flynn effect changed how statisticians looked at intelligence, but not how cognitive scientists did. More studies showed that IQ can be changed by about 15 points depending on things like access to opportunity, SES, and quality of education. Remember that ultimately intelligence quotients do not accurately measure intelligence, just how well the subject does on the intelligence test. So it makes sense that the quality of education and learning will affect the test taker’s score.
However, for the first time, we are looking at cognitive changes within an individual that are based on biology and not outside social forces. A journal article in Nature magazine cites a study by Cathy Price and her colleagues out of University College in London.
Dr. Price administered IQ tests and MRI scans to 33 healthy teens — the first time in 2004, when the kids were 12 to 16 years old, and then a second time in 2007-08, when they were age 15 to 20. They found changes in individual subjects’ performance on the tests, with verbal IQ, nonverbal IQ and composite IQ fluctuating up or down, in some cases around 20 points. In all, 39% of the sample had a change in verbal IQ, 21% in nonverbal IQ and 33% in composite IQ.
When MRI scans were examined, the changes were most often associated with the parts of the brain relating to speech and hand movement.
What this means is that there is greater plasticity in the developing brain than originally thought, producing huge implications for education.
“We have a tendency to assess children and determine their course of education relatively early in life, but here we have shown that their intelligence is likely to still be developing,” Price said. “We have to be careful not to write off poorer performers at an early stage when in fact their IQ may improve significantly given a few more years.”
Now, if we can find the money to pay our teachers…
Photo credit: sobriquet.net