IQ has proven to be a controversial subject since the invention of its measurement in 1905 by Alfred Binet. Binet produced an intelligence scale and proceeded to measure the intelligence of people against it, but it wasn't until 1912 that William Stern coined the term Intelligence Quotient and proposed stating intelligence in this way.
Yesterday, I was asked my opinion of intelligence testing by a reader, and I answered him or her - for it was an anonymous comment - in the comments after my previous post about homeschooling. However, since remarks often get lost in comments, I am readdressing the matter here.
IQ tests can reveal useful information about a person's ability - but at the same time there is much that they do not speak of. People have elevated intelligence tests a little too much over the past century and have lost sight of their essential limits. I will look at what they do well - and what they don't do at all.
IQ tests propose to measure g, a general intelligence factor, by setting a number of tasks, mostly verbal, logical and mathematical, though some tests include spatial tasks, as well. Through one's performance on these tests, which are characteristically successively harder throughout the test, a magical number is produced at the end: an IQ. This number has been taken in our culture to be of great significance, a means by which to rank humans from the smartest to the dumbest.
What real world validity does this idea have? Well, IQ correlates quite well with academic performance and with real life job performance. It also, rather strangely, correlates with general health, longevity and socioeconomic status. So, it is measuring something, however indirectly, that has a real world effect.
What does a high IQ say about a child? It says that the child's convergent reasoning ability - the ability to converge on a single answer in problems that have but one answer - is greater than his age peers. The higher the IQ, the rarer is that ability. An IQ of 130 indicates a child - or adult - that is moderately gifted - and is present in about 1 in 44 of the population. An IQ of 145 indicates highly gifted and is present at about 1 in 1,000. An IQ of 160 indicates exceptionally gifted and is present at about 1 in 10,000. Finally an IQ of 180 indicates profoundly gifted and is present at the rate of 1 in 1,000,000. Higher IQs are rarer still.
High IQ is very useful for people who work in professions where this kind of thinking is at work - law, accountancy, and medicine, where, oddly, the mean IQ for members of these professions is 128 each. The mean IQ of researchers is only 131 - 134 depending on the study looked at. So, clearly, any child who is gifted has all professions open to them.
Yet, there is something important that IQ does not speak of: creativity. Genius is not fully captured by IQ tests. Most geniuses have high IQs, but most people of high IQ are not geniuses - in fact, almost none of them are. Why is this? It is because creativity requires a very different kind of thinking than what is measured by IQ tests. The ability to come up with a new idea is NOT the same as the ability to solve a problem in an IQ test. There is not really any relationship there.
Thus what does it mean if your child has a very high IQ? It means they are very likely to do well in school, and quite likely to do well in life. They will have access to the widest range of jobs and they will be able to do well at those jobs. But it does not mean that they are going to be the next Einstein, Goethe or Shakespeare. The gift required in those areas is a different one. They MAY indeed by the next Einstein, Goethe or Shakespeare - or indeed Leonardo da Vinci - but the evidence of an IQ test is not enough to show that this is so. To be as great as those thinkers of the past, one would have to possess a special creative gift in an appropriate area. If that gift is present, it should be obvious to an observant parent - and, if nurtured, it could blossom into something wonderful. Such special gifts don't necessarily require a very high iq to support them. So, if your child does not have a high iq, but perhaps has a more moderate one, don't despair - for that does not mean that your child might not be a great musician, or artist, or might possess any number of gifts.
There are, in short, children who are gifted on IQ tests, who are good at convergent reasoning. Then there are children who are good at creative tasks, and who could shine in a creative pursuit. They may not be "gifted" according to an IQ test - but they are very much gifted people. Then there is a third group of people who are both gifted in terms of IQ and gifted in terms of creativity. These people have what it takes to be a true genius.
(For a guide to the blog site, and an introduction to Ainan Celeste Cawley, six, a scientific child prodigy, and his gifted brothers, go to: http://scientific-child-prodigy.blogspot.com/2006/10/scientific-child-prodigy-guide.html