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Thoughts on IQ testing for young children and school applications March 10, 2007

Posted by cnchapman in Psychology.
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After having gone through an extensive process of school applications with family, I’d like to address the question of IQ testing for school admissions. IQ tests are used by some public gifted programs as well as some private schools. This is a controversial issue, so I’ll simply issue a blanket apology in advance!

I can address this from two kinds of experience: (1) I was a clinical psychologist before moving into technology research and had extensive training and experience in both adult and child psychological assessment; (2) my own child recently took a standard assessment instrument to apply to school. This is a long post, but there are many important issues here and I’d like to try to be very clear. Note that I’m not an active psychologist any more (it’s been 7 years since I moved to a research position), so take my opinions as educated but not as professional advice.

BTW, in the main part of the post, I leave aside most questions about the validity of IQ assessment. People’s opinions are strong and vary for good reason. If interested, see the “Appendix” at the very end of this post for my position on those issues. Also the comments here are specifically directed at IQ testing for admissions purposes; they do not necessarily apply to IQ assessment used for diagnostic or counseling purposes.

First, there is the question of when to do an IQ assessment. There are assessments for kids as young as 3. However, there are a few things to consider. Perhaps the most important thing to consider is this: cognitive abilities develop quite differently both within and between children. It is not until around age 10 that one can assume that all cognitive abilities will have caught up to one another and more or less stabilized with relative strengths and weaknesses that they will retain later.

What does that mean? Think of physical growth as an analogy. Just as kids go through growing spurts, cognitive abilities likewise can develop in bursts (the “switch” of speech turning on at age 1-3 is one good example). Just because a kid is “behind” at age 4 doesn’t mean that he or she will be at age 8. The same is true of different abilities compared to one another: for some kids, vocabulary may develop faster, while for others it may take longer, even if they ultimately arrive at the same place. In short, an earlier assessment is informative, but more variance can be expected the younger the child is.

Another implication of this is the following: unless a child shows clear deficits within an assessment battery, the main information one gets is that things are “OK” with reference to some norm. It is much more difficult to read significance into the differences between scores (e.g., verbal vs. math) when a child is very young. So the information gained from testing is limited, apart from diagnostics. This is why so much assessment at very young ages is focused on identifying problems and how to address them. That is very different than, say, an assessment with a 12 YO where the relative strengths and weaknesses of skills can be more clearly and reliably assessed.

The second thing to consider is what action one would take on the basis of an assessment. Suppose a school has a particular cutoff (I’ll say more about that below). Given the variance factor, if you’re within 5-10 IQ points or so above or below that, it can be difficult to know what to expect from another test a year later. So the expected outcome can be difficult to plan ahead of time.

My suggestion for any assessment battery is to discuss what you’re looking for with the psychologist who administers the test. In particular, if the main purpose is for school admission, I would suggest careful consideration of which assessment to administer. For instance, if you want to predict a Wechsler score (WPPSI, WISC), it would be most predictive to give a Wechsler test – but this has to be weighed against the fact that the schools will know about the repeated assessment, and that you’d learn less over the course of things than if you gave different assessments (e.g., Wechsler and Stanford-Binet).

I would offer one strong suggestion about an assessment: do not use the words “IQ” or “test” with a child. This process should be viewed as fun and enjoyable, not as something to stress about. If they feel that they’re being tested, it may affect the results negatively. I would describe it instead as something like, “you’ll get to do a lot of different activities, such as looking at pictures and playing with blocks.” The psychologist can take it from there.

Third is the question of how the issues around assessment relates to schools and choosing among them. I don’t have a good answer there, except that I think it is matter of the fit between the child’s temperament, the family’s goals, and the school’s emphases. Family goals differ a lot in education: some families view academic rigor as the sine qua non of schools and want a school to emphasize reading, math, and other such performance measures. Other families are interested to encourage artistic, physical, and emotional development along with academics.

Likewise, there is the question of individual needs of the child. Some gifted children have special emotional needs and benefit from being in homogeneous groups with other gifted kids, while others may do better in a more mixed environment where they interact with a diversity of others. Although no doubt kids can go “faster” to learn academic material in an accelerated environment, that doesn’t mean that every gifted child should do so. There is plenty of time in life (high school, college, grad school) to learn academic material; it just depends on the goals and temperament of the child.

In visiting a number of schools, I’ve seen significant variation on all of those dimensions. Some emphasize academics, while others emphasize as “balanced” curriculum. Some focus on building a close-knit environment where elementary students spend most of their time with 1 teacher, while others have kids changing activities and teachers multiple times a day (sort of like high school).

Finally, it’s unsolicited, but I would share one concern I have as a former psychologist: I think it is questionable whether IQ tests should be used to enforce a cut-off criterion for admissions. IQ tests were developed primarily to conduct assessment of individual strengths and weaknesses – not to serve as selection criteria. This is markedly different than, say, the SAT, which has been explicitly designed for selection purposes. Suppose a school has a cutoff of, say, 96th percentile on an IQ test. How is it that they determined that 96th percentile was the correct cutoff? How do they know that the test is reliable? Individual scores can easily vary by 5-10 points from time to time.

Also, how do they know that the test used for selection has been administered appropriately? Simply using a licensed psychologist is not enough. Selection tests such as the SAT are kept secure and secret until administered in order that everyone taking them is on a level playing field. IQ tests, however, are not secret – it is easy to take the same test multiple times, or with a bit of research even to find the items and their answers (the list of items does not change from person to person or time to time).

My take on it is that some schools like to use the IQ cutoff for two reasons: (1) it makes admissions easier for themselves (esp. in public school gifted programs, where they don’t want to argue endlessly about decisions), and (2) for marketing (it makes people feel good to be in the top X%). That doesn’t mean a school is wrong to use them for those purposes, nor that the school is “bad” for using them in an arguably questionable way. Rather it’s just that one should be clear about what’s happening.

A better approach, IMHO, is when IQ assessment is used not for cutoff purposes but rather as a way to get a better picture of individual strengths & weaknesses. For instance, one school explained that they don’t want classrooms full of kids who are all stronger on one dimension (e.g., language) vs. another (e.g., math), and they use the results both to understand more about each child’s needs and to select balanced classes. Given that young children’s performance varies so much in developmental course, that usage is also suspect in practice, but it makes much better sense than an arbitrary cutoff. As always, I’d certainly suggest to discuss those concerns with both one’s psychologist and the school.

Appendix: My $0.02 on IQ “validity”

As a former psychologist, I’d summarize my take on IQ like this: IQ is scientifically “real” in the sense that it can be measured repeatedly and reliably. IQ is “not real” if one takes “real” to mean that it completely defines one’s intelligence or potential. IQ is at least partially determined by both genetics and environment, but researchers differ over how much of a contribution each makes (not to mention that they are highly confounded). Studies of identical twins (including ones separated at birth) suggest that it IQ somewhere around 40-70% determined by genetics – which means 30-60% determined by environment. IQ can be modestly enhanced on the positive side through better environments, but when there is a stable family structure with decent environment, trying to do much more is unlikely to change it.

Some researchers and others have argued that IQ tests demonstrate “cultural bias” (e.g., to the advantage of traditional & suburban families, European heritage, etc), but the research evidence for that is not completely clear. Top-notch assessment developers (e.g., Wechsler, Stanford-Binet, Kaufman) are very sensitive to those issues in the latest versions of tests and have attempted to address them. (I don’t want to get too deeply into the cultural issues here – but it’s something to discuss with a psychologist, if that is of concern). Again, it’s important to realize that IQ doesn’t measure everything – it’s just one particular subset of cognitive skills (which vary somewhat from one test to another).

IQ is one of the best predictors — but not perfect, of course — of later success in strongly academic subjects such as math, vocabulary, etc. However, those are only modestly predictive of other kinds of success in life because there are many other ways to succeed or fail. IQ is modestly affected by “practice effects” of taking the tests repeatedly, but psychologists are on the lookout for that and there are some ways to control for it (e.g., by using a different test, or reporting that it has been taken before).

Once one achieves a “high enough” IQ (top 15% or so), then virtually all potential careers are open in terms of intellectual ability – the differentiating factors are likely to be personality, opportunity, motivation, etc. For instance, the average IQ of attorneys and physicians is said to be the same as that of professors at Ivy League colleges (it’s supposedly between 120-126). In other words, once that level is reached, the differentiators lie elsewhere. There are a few exceptions (e.g., physicists and philosophers are likely to be very high), but even then it is not IQ that is the ultimate predictor of either interest or success.

Even within the areas that IQ tests assess, some skills are more important than others for various professions. For instance, it would be difficult for someone with relatively lower verbal performance to be an attorney or writer, but that wouldn’t necessarily stop them from being, say, an engineer or an accountant. It’s also important to remember that the vast majority of people are within 1 standard deviation of “average” (85-115) and do quite well in life (or, rather, whatever problems they have lie elsewhere).

Finally, there are many other kinds of “intelligence”. That is not to deny that IQ is “real” in some abstract sense, but there are also other abilities that can be just as important: “emotional intelligence”, artistic and musical ability, physical/mechanical aptitude, and so forth. Our society tends to focus strangely on “intellectual horsepower”: society mocks it on the one hand, yet regards it as supreme in some other ways (e.g., in some kinds of academic selection). It is feared and worried about — perhaps because it is rather observable and has the property of being important for some kinds of success yet is largely fixed early in life, which goes against the American egalitarian view.

In short, don’t take IQ for more than it is, or even worry about it until you have a reason to do so. At the same time, that doesn’t imply that one must deny whatever it does mean.