Greetings. I’m now trying the new editor function for WIN members by posting an English translation of an article I wrote for my own homepage a couple of months ago, which was originally written in the German language.
Why should one deal with such an abstract topic as the term “intelligence” even though encyclopedias such as the famous German clinical dictionary Pschyrembel clearly state that there is no commonly accepted definition of intelligence? As a matter of fact, despite the non-existence of a generally accepted definition of intelligence, there are tests claiming to measure the intelligence of a person, and many people at least respect, if not even fear such tests. Why? This may be due to the claim you often hear in everyday life that intelligence is something important, and maybe it is also related to the notion that used to be widespread in former days, that those who are less intelligent are less valuable. Anyhow, in our society there seems to be the tendency to adapt to norms. People who deviate from the norm in some respect are expected to try hard to get assimilated, otherwise they are marginalized. This also applies to intelligence. Often a correlation between intelligence and the degree to which an individuum is socially adjusted is postulated: If somebody deviates from the norm, for whatever reason, some people tend to attribute a lower level of intelligence to this person. From this aspect, intelligence tests may have a liberating effect as they enable people to demonstrate that they, after all, are not less intelligent than the mean. On the other hand, too high intelligence may also lead to marginalization as too high intelligence is also abnormal in some way.
There are so many different definitions of intelligence as there are intelligence tests. That’s why some experts have come up with a pragmatic definition: Intelligence is what the intelligence test measures. Alas, what sense does it make to create tests testing nothing but the ability to pass the test? Well, intelligence is supposed to be more or less correlated to several things: for instance, school grades, income and health. However, this leaves two questions open: First, what is the cause and what the effect (am I so good at school because I’m so intelligent, or am I so intelligent because I regularly do my homeworks and study for exams)? Second: What sense would it make to do intelligence tests if the level of intelligence could be already derived from these other parameters (grades, income etc.)?
It is certainly a matter of fact that a rather high level of intelligence is required for achieving a high level of education. You need not be “gifted” to become an academic, but most academics are probably above average. For this reason, intelligence tests seem to be especially useful for the detection of “underachievers”, that is people who, despite being very intelligent, have not achieved what one would expect from highly intelligent people. These people could be detected with such tests and specifically supported. The other thing in the high range is the detection of “giftedness”. Alas, giftedness is an arbitrarily defined feature: The border between slightly above average intelligence and giftedness is at two standard deviations above the mean. Are human beings with an intelligence quotient slightly above that limit really different from people whose intelligence is slightly below? At least my experiences tend to say no: People visiting Mensa meetings although they failed the admission test (yes, there are such people in our local chapter here in Vienna) usually do not make themselves conspicuous. Differences can, if at all, be noticed when playing board games – some need less time to understand the rules and make fewer mistakes than others.
As a long-term Mensa member I am able to make the following statement: The personalities of the members are just as different as those of ordinary people. However, internal surveys showed that Mensa members tend to score as “intuitive” in personality tests based on the typology of C. G. Jung, and only few are “sensing”. What do Mensa members have in common except high intelligence? At least here in Vienna it can be observed that they hardly drink alcohol. That distinguishes them greatly from other people I have had to do with, such as my classmates at school. There is also a striking breadth of interests; it is possible to talk with Mensa members about all kinds of topics on a rather high level.
At the other end of the scale there are the mentally handicapped. Here we have an interesting discrepancy between the prevalence indicated by medical textbooks and the number that would result from the Gaussian distribution of intelligence. While according to test theory the number of gifted people should equate to the number of retards (a bit more than two percent of the population), medical textbooks state a far lower number of mentally handicapped. These intelligence losses are mostly due to chromosomal disorders and genetic diseases, but also alcohol and drug consumption of the mother (especially smoking) play a role.
Ordinary intelligence tests are not suited for classifying mental handicaps. After all, it requires a certain level of intelligence to even understand what the tasks in these tests are all about. In this low range, intelligence is usually measured based on features that are interpreted as developmental disorders. This is founded on the idea that all children go through the same developmental stages and the differences are only due to some developing faster and other more slowly. Whether this model matches reality is still a matter of controversy.