> Posted: May 30, 2012 12:46 PM by Paul: > > > What I'm talking about is this fact: If we were to > > take the same set of people such that some do and > > some do not obtain PhDs in different areas > including > > mathematics and who were given the same > well-designed > > aptitude test like an IQ test (say the Wechsler > test) > > all throughout their lives, there is a high > > probability that the average measure of that set of > > people on that test would not change to a > > statistically significant degree, regardless of the > > level or type of knowledge they acquired over that > > time. Can you name a pure achievement test that > shows > > such a result - where *statistically speaking* we > > would essentially see essentially the same average > > score on the same test all throughout their lives > > regardless of level or type of knowledge acquired > > throughout their lives? > > >
I wonder if this has ever been directly studied. Take a group of, say, 10-year-olds who all score similarly and above average. Follow them throughout life, with some earning PhDs and some not, in various fields, and test them again looking at individual scores. IQ scores do change for individuals, even though statistically speaking over large groups they do not. I know they have followed students over the course of K-12 and they have found great variability in individual scores.
"We were very surprised," researcher Cathy Price, who led the project, tells Shots. She had expected changes of a few points. "But we had individuals that changed from being on the 50th percentile, with an IQ of 100, [all] the way up to being in the (top) 3rd percentile, with an IQ of 127." In other cases, performance slipped by nearly as much, with kids shaving points off their scores.
Price and her colleagues used brain scans to confirm that these big fluctuations in performance were not random ? or just a fluke. They evaluated the structure of the teens' brain in the early teen years and again in the late teenage years.
"We were able to see that the degree to which their IQ had changed was proportional to the degree to which different parts of their brain had changed," explains Price. For instance, an increase in verbal IQ score correlated with a structural change in the left motor cortex of the brain that is activated when we speak.
There are lots of factors that may explain changes in IQ. Though this study did not attempt to nail them down, lots of prior research has found that educational environment is key. Some researchers have found that rigorous academic curricula lead to improved IQ scores.