Intelligence & IQ

“IQ” stands for “Intelligence Quotient”, where a quotient is one quantity divided by another. In the case of IQ, the “intellectual age” of the child, that is the age at which the average child would perform at a given standard, is divided by the child’s chronological age at the time of testing; the result is multiplied by 100 in order to give a range of numbers which are easy to deal with, without having to bother with decimal points. A child performing at exactly the average cognitive age has an IQ of:

                        intellectual age/chronological age X100

so that when these two ages are equal, the child's IQ is 100 - therefore by definition the "average" IQ of the whole human population is 100; that is, the majority of people function cognitively at the level which is normal for a person of their age.

IQ is one of the many naturally occurring variables, or factors, in nature, which form approximately what is called a roughly "normal" or "bell shaped" distribution, meaning that if one collects a very large number of randomly chosen IQ's and plots the number of results for each IQ score, the totals will form a curve shaped as follows:

However, I said that IQ forms "approximately" a bell-shaped distribution because in recent years statisticians have found that there seem to be more people with very high IQs (say, above 140) than would be predicted by the bell-shaped distribution. (I had previously noticed this in a practical sense; I was surprised at the high number of highly-gifted children I was contacted about, by parents or teachers. I contacted the Australian Bureau of Statistics to find out the latest numbers of children of each age group in Australia, and calculated that either every highly-gifted child in Australia was in touch with me, or there were more of them than the statistics said there would be. It's a reminder that all our ways of describing these complex natural issues are only approximations; we don't yet know everything, by a long way!

The "average" or most common IQ score in a large population of people, is by definition 100: that is, the majority of people function cognitively at the level which is normal for a person of their age. However, please do note that people of "average" IQ don't usually have any reason to enquire about gifted children's' issues - so the fact that you're reading this very probably means that your IQ is well above average.

Almost half the population has an IQ between 90 and 110. The generally accepted definitions of mental ability across the range of IQ scores, with the descriptive terms psychologists use to describe each sub-group of scores, are as follows:

IQ SCORE	PERCENTILE	DESCRIPTION
160 - 169 150 - 159 140 - 149	0.03 0.2 1.1	VERY SUPERIOR
130 - 139 120 - 129	3.1 8.2	SUPERIOR
110-119	18.1	HIGH AVERAGE
100 - 109 90 - 99	23.5 23.0	NORMAL OR AVERAGE
80 - 89	14.5	LOW AVERAGE
70 - 79	5.6	BORDERLINE DEFECTIVE
60 - 69 50 - 59 40 - 49 30 - 39	2.0 0.4 0.2 0.03	MENTALLY DEFECTIVE

"Mental Age"
The concept of "intellectual age" or "mental age" puzzles a lot of people. If a child is assessed when she or he is 4 years old, and is found to be reading and performing in some other areas of the test at the level of an average 8 year old, the parents may be told that "he or she has a mental age of 8" for reading and the other relevant activities.
What does this actually mean?

It means that in reading and various other activities, the child is working at the level an average child in our society would reach when he or she is 8 years old, so that in some respects she or he is functioning rather the same as an 8 year old. It certainly means that ideally, at school he or she should be allowed to work at 8 year old level, and in our completely age-structured school system the best way of doing this may be to allow her or him to work in a class with 8-year olds, for reading and other academic activities.

Does it mean that mentally the child is virtually an 8 year old? No, she or he is something betwixt and between. He or she is still a 4 year old in many ways, and is more mature and somewhere in between in other ways; and as already stated, for reading and some other academic activities, is at the level of an average 8 year old. Because of the extensions of mind which giftedness bestows, this 4 year old may be interested in concepts and concerns which other 8 year olds aren't usually interested in - in some cases, concerns which children aren't usually interested in until tertiary years, though that may partly be simply because it's an area of knowledge and concepts which our society has decided not to deal with in primary and secondary school.

However, the concept of this child's mental age certainly becomes a complex issue, with aspects such as "what is his or her mental age as it relates to the current school system?", and "what is his or her mental age as an individual, as we, her or his family, come to understand it?", and "what is her or his mental age in the sense of areas of knowledge which are so important to him or her, that provision needs to be made for her or his needs to be addressed in those areas, even though it wouldn't be needed for other 4 or perhaps even 8 year olds"?

The first aspect, how the child's mental age relates to the current school system or similar organisations in our society, can perhaps be understood better by comparing IQ to another variable we measure in children, and for which we tend to have a concept of the average for a child's age, such as height. Height is also "normally" distributed in the population - that is, it follows the same bell-shaped distribution as IQ does; most children are around the average height for their age, some are taller, some are shorter, and a very few are very tall or very short. Because it's something we can see, it's easier to understand what variations in children's height mean. So let's make a comparison with a 4 year old boy who's as tall as an average 8 year old. What does it mean?

Noone would assume for a moment that he is virtually an 8 year old; but on the other hand, obviously he is going to have to do some things like an 8 year old - for instance he's obviously going to have to wear clothes designed for an average 8 year old. Would he be better off playing sport with 8 year olds? That would probably depend on the individual child; for one boy it might work well. For another, in some ways his motor skills may not be sufficiently developed for him to play with 8 year olds; on the other hand it probably wouldn't be very appropriate for him to play competitive sport such as "little athletics" with 4 year olds - he might fit in better somewhere in between. His unusual height puts him in some ways "betwixt and between". One problem, which I've noticed from my own experience with young children who are very tall for their age, is that adults and even other children dealing with him, will tend to assume he's older that he is, and to expect more mature behaviour from him. And so on: the fact that this boy is the height of children twice his age creates a complex situation, which he and those who deal with him will have to make all sorts of adjustments to, including remembering that among all the other issues, he is after all still a 4 year old, and has the right to behave like a 4 year old, and to receive any allowances which are usually made for 4 year olds.

Height isn't primarily a mental aspect of ourselves, while intelligence is. Height can be seen, while intelligence as such, can't. Height is a reasonably straightforward thing, while intelligence is so complex we still don't really know what it is. Having a "mental age" much older than a child's years means there is a complex situation involving that child - that in some ways he or she will seem like an 8 year old, and in some activities it will be best for him or her to join in with the 8 year olds. In other activities it may be best for her or him to be with children aged somewhere in between. Most of all, the child with a mental age greater than his or her years will have a corresponding problem to the unusually tall child regarding other people's perception of him or her, only the other way around - people will constantly expect her or him to behave and achieve like the 4 year old she or he physically appears to be, and will feel that all is well (particularly for the school, or other organisation), if he or she knuckles under and does obligingly take part in activities with the 4 year olds. Only very perceptive or unusually knowledgeable adults will be able to see or understand that the child her or himself may be quite out of place among the 4 year olds, and may be unhappy there in many ways.

Any way in which any of us is very different from the average in the population, causes a complex situation for us; it will cause unusual needs, special requirements, and constant problems regarding other people perceiving us as what we appear to be rather than what we really are. Because intelligence is an important part of our personality, it's even more important that the needs and requirements are met, and that both we and our parents spend quite a lot of time if possible, with other people like us.