Psychometric theories have generally sought to understand the structure of intelligence. But measuring intelligence and determining how intelligent we are is very challenging. As we are going to see, the debates on the appropriateness of I.Q. and the limitations of I.Q. testing are still in progress.
At the beginning of the twentieth century, Alfred Binet and Theodore Simon devised the first tests of intelligence in order to identify retarded children and to place other children in the proper educational setting. The tasks and tests were soon available for widespread use. In fact, intelligence testing was considered for a long time psychology’s greatest achievement, its chief claim to social utility and an important scientific discovery.
In 1939, David Wechsler published the Wechsler-Bellevue Intelligence Scale. This was an individual test specifically designed to correct some of the deficiencies of the old Stanford-Binet. It was a test for adults, not so verbally oriented. The entire test was divided into a Verbal Scale and a Performance Scale and a separate I.Q. score could be calculated for each of the two scales. Since the original Wechsler-Bellevue appeared, a whole series of related tests have been published: Wechsler Intelligence Scale for Children (WISC), Wechsler Preschool and Primary Scale of Intelligence (WPPSI) and Wechsler Adult Intelligent Scale (WAIS). Overall, the Wechsler scales show a high quality of technical construction.
The first generation of psychologists of intelligence, such as Charles Spearman and Lewis Terman, tended to believe that intelligence was best conceptualized as a single, general capacity for conceptualization and problem solving. Their theory, known as the theory of general mental ability, was started by Sir Francis Galton (Charles Darwin’s cousin) and sought to demonstrate that a group of scores on tests reflected a single underlying factor of ‘general intelligence’, the factor g. Spearman interpreted g as the core of human intelligence that influences success in all cognitive tasks and thereby creates the positive manifold. Each individual is born with a certain amount of intelligence and can, in fact, be rank-ordered in terms of our God-given intellect or I.Q. Scholars such as Sir Cyril Burt, Arthur Jensen and Hans Eysenck have maintained their belief in the singularity of intelligence and kept loyal to psychometric instruments. Their ideas formed the ‘tough-minded’ wing of intelligence studies.
Today the theory of general mental ability and the g factor are accepted by many psychometricians. The critics of I.Q. believe that to base a concept of intelligence on I.Q. test scores alone is to ignore many important aspects of mental activity. In terms of abilities like reasoning, reading capacity, verbal ability, information acquisition or analytical capacities, I.Q. tests can be valid, but, if we talk about such things as ‘street smarts’, common sense, the ability to be a survivor, or even wisdom, they can also be not. Many scholars are convinced that enthusiasm over intelligence tests has been excessive and that they are instruments with numerous limitations. Howard Gardner, Hobbs Professor of Cognition and Education at the “Harvard Graduate School of Education”, talks about a mania for evaluating people for specific purposes which fuelled the excitement over intelligence testing. Gardner’s objection to I.Q. tests is that they reveal little about an individual’s potential for further growth. To put it in the terms of the psychologist Lev Vygotsky, intelligence tests fail to yield any indication of an individual’s “zone of proximal development”. The I.Q. movement also ignores biology and is insensitive to the power of creativity.
The biggest problem with standard tests and the I.Q. model is that they measure intelligence too narrowly, based on how well the student reads and computes. Only a few of an individual’s abilities, the ‘scholastic’ intelligences, chiefly the linguistic and logical-mathematical, are assessed. Designing reliable and valid tests for assessing students’ musical or artistic talents, for example, is much more difficult and surely more expensive.
We can conclude that the I.Q. movement is blindly empirical. It is based simply on tests with some predictive power about success in school and only marginally on a theory of how the mind works. Like any score, I.Q. is the product of numerous converging factors. Some of these factors may reflect intellectual potential. But others may involve motivation, health, education and cultural background. I.Q. scores do not readily reflect innate ability, practical abilities or even wisdom. Still, the concept and the measurement of intelligence remain a curious paradox.
Eysenck, H.J. (1998), Intelligence: A New Look, New Jersey: Transaction Publishers
Gardner, H. (1993), Frames of Mind – The Theory of Multiple Intelligences (2nd edition), London: Fontana Press
Phares, E.J. (1991), Introduction to Personality (3rd edition), New York: Harper Collins Publishers
Vygotsky, L. (1978), Mind in Society, Cambridge, MA: Harvard University Press