Can intelligence be measured? Does an IQ test actually measure a person’s intelligence? Does a high score indicate a genius? Does a low score indicate stupidity or merely ignorance? These questions have been asked over and over again by psychiatrists and scientists alike, but to date there are no clear answers. These questions cannot be answered without first defining what is meant by the term intelligence. Once intelligence has been defined then it should be easy to answer these questions; however, multiple definitions of the word tend to lead to further confusion.
In a 1921 symposium entitled “Intelligence and Its Measurement”, psychiatrists were asked to define intelligence and their answers varied greatly. One described intelligence as “equivalent to the capacity to learn.” Other definitions included “the ability to adapt adequately to relatively new situations”, “the capacity to learn or profit from experience”, and “the knowledge that an individual possesses.” And one stated that there was no simple definition to the word because “intelligence involves two factors- the capacity for knowledge and knowledge possessed” (Sternberg & Detterman, 1986, p.39-40).
Dictionaries add still more definitions: Funk & Wagnall’s defines intelligence as “The faculty of perceiving and comprehending meaning; mental quickness; active intellect; understanding” , while Webster’s defines it as “the ability to learn or understand or to deal with new or trying situations; the skilled use of reason.” While some of these definitions are similar, none of them are exactly the same.
The definition of intelligence becomes even more complicated when one considers the work of Howard Gardner. Gardner claims that intelligence can not be defined with one definition because intelligence is not one thing. Gardner purports that there are eight different categories of intelligence: musical, bodily-kinesthetic, logical-mathematical, linguistic, spatial, interpersonal, intrapersonal, and naturalist. He is currently considering adding a ninth category of intelligence: existential (Carvin).
Gardner believes that all people excel in at least one category of intelligence. However, he cautions teachers using the multiple intelligence approach in the classroom: “Do not label kids as ‘spatial, but not linguistic’ or, for that matter, ‘linguistic, but not spatial.’ The intelligences are categories that help us discover difference in forms of mental representation” (Durie).
If intelligence is what a person knows or understands then it is possible to measure intelligence; however, if intelligence is one’s capacity for learning then it is more difficult to measure. If you have a bowl and want to know how much water it will hold then you simply fill the bowl with water, then pour the water into a measuring device, and then you know: That bowl holds two cups, 1/2 a liter, or 25 grams of water. There are many reasons why it is not possible to measure capacity for learning in the same manner: One cannot fill the brain with knowledge, pour the knowledge back out, and measure it. First, there is no way to indicate that the brain is full, no way possible to retrieve all of the information, and no measuring device for knowledge: You cannot have 2 cups, 170 grams, or three feet of knowledge (Block & Dworkin, 1976, p.239)
Assuming that intelligence is what a person knows makes it possible to measure intelligence, but finding an accurate measuring device is difficult. The measurement of intelligence began with the work of Francis Galton who attempted to apply Darwin’s theory of biological evolution to the evolution of human society (Lawler, 1978, p.39-40). Although the tests have changed considerably since then, the type of measurement has remained essentially the same.
An IQ test measures intelligence by finding a person’s mental age, dividing it by his or her chronological age, and then multiplying that number x100 (Block & Dworkin, 1976, p.6); however, there is no standard test or testing method. There are roughly over one hundred different tests with the most common of these being the Stanford-Binet test (Lawler, 1978, p.29) The test is administered either through group or individual testing.
In group testing literacy is required and each person simply takes a timed written test. In individual testing literacy is not required: Each individual meets privately with a test proctor and takes a mostly oral examination. For example, a child of three would be asked to string beads, identify individual pictures by name not use, build a bridge with blocks, identify a specific article from a picture shown earlier, draw a circle, and draw a vertical line. Test questions become gradually more difficult with age (Lawler, 1978, p. 29-33).
While most of those in the psychological field agree that scores from individual tests are more accurate than scores derived from group testing, many still argue the validity of the test (Block & Dworkin, 1976, p.350). One psychiatrists has said, “the tests are accurate at defining mental age in comparison”, but went on to add that, “mental age and intelligence are not necessarily interchangeable terms” (Sternberg & Detterman, 1986, p.41).
The number of different tests creates a problem with scoring a valid IQ. In a 1973 study, students were given three different IQ tests on the same day. The students were not given the same exams in the same order. For example student 1 would take test A, then test B, and end with test C; while student 2 would take test B, then test C, and end with test A. The results of the tests showed staggering differences of up to 40 points in IQ. There was no one test that all students scored consistently high on, nor was there a test that all of the students scored consistently low on. The order of the tests also had no effect on the scores (Lawler, 1978, p. 40-43).
Gardner’s theory of multiple intelligences defies testing. Current IQ tests measure less than half of Gardner’s catergories and then the results are combined into a single IQ score. Many of his catergories can not be tested with a standardized test. For instance, Gardner defines his newest catergory of intelligence ( the naturalist) as including a child that knows about dinosaurs, a child that knows different types of vegetation, or a child that knows about trees. There is no single test that can measure knowledge in each exclusive area of the naturalist (Carvin).
Many also argue that the test is biased in the way that answers are scored. For example, one question used in the test for twelve year-olds asks the children to pretend that they have been sent to the store to buy a loaf a bread, but when they arrive the store is out of bread. The children are then asked what they would do with points only being scored for the answer of going to another store; however, for children living in large urban ghetto areas the most popular answer has traditionally been to go home. Researchers argue that, considering the environment that these children live in, going home would be a much more intelligent decision than attempting to go to another store (Lawler, 1978, p.34).
Can intelligence be measured? Does an IQ test actually measure a person’s intelligence? The answers all depend on who you ask.