Friday, March 15, 2013

What is IQ?

Sandeep Gautam wrote in “Why IQ is a Myth”

To me, to be frank a score of 162 or whatever on a test means nothing, and I hardly care if the test is Cattels , WISC or stanford-binet. When a lay person sees a score of 100 or 160 he assumes that a) intelligence can be fully measured and quantified and b) IQ is that measure.”

It is very true that IQ scores divorced from their context are pretty meaningless. It's like saying, “Forty-two is The Answer to the Ultimate Question of Life, the Universe, and Everything” [Douglas Adams, The Hitchhiker's Guide to the Galaxy] Forty-two what? What was the question?

We can list a lot of things that an IQ score isn't:

It isn't The Answer to the Ultimate Question about a person.
It isn't an immutable number carved on your brain.
It isn't able to measure the full range of a person's abilities.
It isn't a measure of someone's worth.
It isn't a map of someone's destiny.
It isn't a limit (or an expectation!) placed on a person's potential.

But instead of underestimating the “lay person”, perhaps we should attempt to explain what an IQ score is. It is information about how a person performed certain tasks, under certain conditions, on a particular day. A full-scale IQ score makes sense only when we understand it in its full context, including: the type of test, its standard deviation, its ceilings, its error ranges, the other composite scores, and the subtest scores. A good tester also makes behavioral observations about how the person approaches problems and emotional factors that may have affected the results. To interpret the subtest scores, we need to understand the specific cognitive abilities being drawn upon by those tasks. A full-scale score is only the broadest summary of someone's performance ranked as a comparison to the scores of others in the same age group. It gives none of the details about strengths or weaknesses.

A typical full-scale IQ score (such as given by the
Wechsler tests), is called a standard score. This score corresponds to a percentile ranking of the sum of the scaled scores of selected individual subtests, which are themselves rankings of the raw scores for each task normed for each age group. It is essentially a measure of “unusualness”. The more unusual subtest scores someone has, the more that will be reflected in the sum, resulting in a more unusual full-scale score. The logic of this process can be confounded in situations where a person's scores in one area are unusually low and unusually high in another, giving the appearance of an average sum. This is why we need to look at the other composite scores (for example, Verbal or Working Memory) and the subtest scores in order to interpret the full-scale score.

An unusually high score, like Neha Ramu's, is possible only when all or nearly all of the subtest scores are unusually high. What does this tell us about a person? It means that in comparison to others her age, she excels in skills that are predictive of academic success, which is what most IQ tests have been designed to measure.

In its various incarnations, IQ has been linked to certain personal characteristics and learning outcomes—I'm not going to summarize those volumes of research here. The important thing to remember when reading about such research is that statistical correlations can tell you only about the likelihood of a given outcome. They cannot be applied to individuals. We cannot know ahead of time whether a person is part of the majority who will experience a given outcome or the minority who will not. The fact that there is such a minority does not invalidate the research, just as the fact that IQ scores may be misunderstood by some does not mean they are useless or absurd.

No psychologist trained to administer IQ tests would claim that intelligence can be fully quantified by IQ. I completely agree that it is sloppy journalism to report Neha's score as evidence that she is smarter than Albert Einstein, and equally sloppy to compare her score to an estimate (Einstein never took the test Neha took). But instead of dismissing IQ tests as nonsense, let's set the record straight.

Wednesday, April 4, 2012

Alert to Gifted Advocates: We Need to Change This Meme!

I just saw it retweeted:

If you’re 130 IQ you're as different from the mean as if you were 70 IQ on the other side. #NAGC ”

Once again, I pointed out that IQ scores are not measures of amount of ability (or need). They are only a relative ranking of scores, corresponding to percentiles. A 30 point interval on one part of the IQ scale may mean a much greater difference in abilities than a 30 point interval on another part of the scale.

This meme is everywhere in the gifted universe:

The child of 160 IQ (top 0.01%) is as different from the child of 130 IQ (top 2%) as that child is from the child of average ability.”

~Leta Hollingworth, Children Above 180 IQ (1942) [1]

There is the numerical answer: a child of IQ 160 is as different from a moderately gifted child of 130, as that child is from an average child of 100. “ [2]

Now move in the opposite direction from 100. An IQ score up to one standard deviation above 100 is considered normal, or average. Move up one standard deviation is mildly gifted. That means that a child with a score of 130 is as different from a child with an IQ of 100 as is the child with an IQ of 70, a score which definitely qualifies a child for special services. Move up one more standard deviation and we move into the range of moderately gifted (130-144). The same range on the other side of 100 is the mildly retarded range.” [3]

Let’s pretend that you take an average child with an IQ of 100. Take this child and put them into a classroom where everyone else’s IQ is 70 and below. In other words you are taking an average child and putting him or her into a school environment where all the classmates are mentally retarded. Not only are these classmates mentally retarded but the curriculum is also geared for the mentally retarded children. “ [4]

What's the difference? Gifted children tend to think differently and learn more quickly than their peers. Compare a gifted child (IQ = 130) to an average child (IQ=100) you will see the difference: the gifted child learns quicker, thinks deeper, and draws conclusions more easily. Compare that gifted child (IQ=130) to the highly gifted child (IQ=160). Again, you will see the difference, in many of the same ways. Now compare the highly gifted child to the normal child, and you face a chasm that by the end of elementary school may place these two children as much as 5 years apart in mental age.

There's another way to look at it. The difference between the exceptionally gifted and the average child is the same as the difference between the average child and the mentally handicapped child of IQ 40. That's a big difference!” [5]

Why does this matter?

  • As advocates we should strive to be accurate. Our credibility is at stake!

  • As advocates we should strive to educate—not spread misinformation just because it is a handy analogy to make a point.

  • Think about how our advocacy is perceived by others: When we make a comparison that implies average people are mentally impaired compared to gifted people, we alienate most of our listeners.

I understand that the goal is to build awareness of the very real needs of gifted children. So instead let's use the real meaning of IQ scores: a high (or low) score is unusual. Unusual kids are likely to need unusual accommodations.

Please, make a small change, gifted advocates! Be accurate, educate, and build awareness without alienating others. Let's start using a new meme:

Unusual kids

are likely to need

unusual accommodations.






Thursday, April 1, 2010

Our first month of homeschooling is behind us. We are still revelling in our freedom: the freedom to choose what to work on and when, the freedom to go hiking on a Friday morning, freedom from homework...

We are meeting more people and making connections with homeschoolers in our area... there are so many activities and exciting opportunities it is difficult to choose what we want to try first!

Part of me worries that this is too good to be true... is this some sort of honeymoon period? Even if it is, I want to enjoy it while it lasts!

Monday, March 15, 2010

A New Path

You cannot take itself
From any Human soul-
That indestructible estate
Enable him to dwell-
Impregnable as Light
That every man behold
But take away as difficult
As undiscovered Gold-

~Emily Dickinson

Somehow, I found the courage to jump off a cliff. It wasn't like me at all... I don't like change, I don't like to take risks... but here I am, homeschooling my two children, Elena and Mac.

Our first weeks have been spent rediscovering their interests and passions. As the days passed, my anxiety has turned to relief; my joyful, curious kids have reappeared. Mac has suddenly found that he likes to draw, and is producing a detailed imaginary world.

Elena was inspired to learn and write about Elizabeth Blackwell... I am amazed by their ideas and questions, and I'm excited to find out what they will come up with next!