ABSTRACT
The first intelligence tests to be produced were those devised by a French psychologist called Alfred Binet who, with his collaborator, T. Simon, published a scale for the measurement of intelligence. This scale was to be administered on an individual basis by the psychologist and not in a group situation such as many readers may have encountered in public tests of intelligence. The aim of the test was to select those children in Paris schools who were below the normal standards of educability so that they could be sent to special schools. The scale was revised twice until by 1911 it consisted of a number of test items arranged according to the age at which they are usually passed. Thus, for example, the average child of five years of age would be able to answer all the questions on the scale below the five-year-old level, all the questions on the five-year-old scale, but none of the questions above the five-year-old scale. Such a child would be, according to Binet's definition, exactly average. On the other hand a child of four may also be able to answer all the questions on the five-year-old scale. This child would, according to Binet's criterion, be above average, while a child of six making the same score would be below average. Binet then introduced the concept of mental age which is derived by discovering the test level which an individual attains. Thus all three children mentioned above would have mental ages of five. In general, of course, children do not produce such a neat, clear cut, pattern of scores, but generally cope with all the tests at one level (this is termed the ‘basal’ age) and in addition they answer some of the questions in the tests one or two years above this basal age. An example of a child's score in a Binet test may help to make this point clearer.
