I am just wondering if those of you in the know can help me understand what evidence there is that IQ scores from testing conducted when children are young (say from 4) are likely to be an overestimate and will often stabilise to a lower score when a child is older. I ask because I often see that comment here but it goes against the information I have been given from other (also knowledgeable) sources. I hope I am not sounding disrespectful to those of you who know significantly more about testing than I do - I guess I am just trying to straighten it out in my head (I should note my daughter was tested early, but the level she works at supports her test results). I know statistically regression toward the mean would indicate that all things being equal outlier scores should go down on subsequent tests, but it would be difficult for �all things to be equal� with early testing of gifted kids (which I guess would also contribute to how valid the norming sample is - apologies if I am using incorrect terminology). I have been scouring my uni�s journal library for information and can only find information saying testing prior to 4yo being unstable. I have heard Miraca Gross talking about this matter and she said that in her experience results before 6 are often unstable, but are usually an underestimate rather than an overestimate and this was also the experience of our tester, who preferred not to test before 4 but felt that the result from then were likely to be stable or an underestimate (she only tests gifted kids).
The reasoning that both Miraca Gross and our tester gave is that often younger children don't engage as well with testing when compared to older kids and they are often less likely to complete the subtests to the level they are able - simply due to test fatigue, lack of concentration etc. These kinds of things would seem to cancel out the regression to the mean argument because it means you don�t have an accurate position to begin with (I have only a very basic knowledge of statistical analysis so I am piecing together bits and pieces and appreciate my logic may be very flawed!)
Like I said, I tried to track down some studies, however the ones I found were either conducted with autistic kids or �at risk� kids. While each of the studies that I found on autistic kids stated testing in preschool and then follow up testing produced statistically stable results, I didn�t know whether or not that was likely to be the same for gifted children. The results for at risk kids showed a decrease that correlated to the number of risk factors they were exposed to, but this wasn't really the information I was looking for. I found a couple of studies on the stability of intelligence scores in general, but was unable to access them due to a system problem.
I am just wondering if those of you who know such things could shed some light on this for me. Thanks!
