Mental tests
Mental tests have been part of our lives for well over a century. We have become accutomed to their use in schools, industry and mental health settings. Yet a century ago the idea that something as subjective as the "mind" could be measured and expressed in numbers was revolutionary. When the first practical test was introduced in this country around 1900 it crreated a sensation.
Prior to 1900 there were some false starts to devellop tests of ability. Scientists reasoned that intelligence requires accurate response to sensations and rapid bodily reactions. It was believed that by measuring the ability to perceive small differences in weights and to respond rapidly were good places to start. Instruments were constructed and statistical procedures developed to analyze these measurements. Psychologists learned a great deal about how the body perceives and reacts to stimulation but the measures did not prove to have any relationship to how well you did in school or on the job. Clearly a new approach was needed.
Breakthorugh
Progress was made but for poor reasons. Today educators are sensitive to the rights of all children to an education, even those with severe physical and mental handicaps. In France, at the turn of the century, concern was for just the opposite. Schools wanted to exclude children whom they labeled as "mentally deficient." But how to identify these children, who were presumed to be unable to learn, was a problem. Alfred Binet was given this assignment.
Binet had an idea that was brilliant for its time. Since the difficulty children had was in handling school tasks, he chose many of those tasks in identifying slow learners. The tasks included building a three block tower, stringing a set of different shaped beads to match a model, defining vocabulary words, and recognizing similarities between two different objcts such as an apple and a pear. Once he had a set of items hested a large group of children at each age level--two year olds, three year olds, four year olds, and so on. He identified a set of items that could be successfully completed at each age level. He was then able to test other children to determine the age level items they could handle. If a child could succeed at all of the items at the six year level, half of the items and the seven year level, and none of the items at the eight year level, Binet concluded that the child has "mental age" of six and a half. If the child performed significantly below his chronological age level, she was declared "mentally deficient." The procedure was termed the Binet-Simon Scale after its developer and his collaborator.
The scale was introduced to this country by Henry Godddard, a psychologist at The Vineland Training School, Vineland, New Jersey. The procedure quickly spead to other schools and facilities.Later, Lewis Terman, a psychologist at Stanford University improved the scale. He recognized that mental age was meaningful only in relation to how old the chiild actually was.Terman started using a simple ratio of mental age divided by chronological age, labeling this quotient the "Intelligence quotient" or IQ. Terman and his colleagues developed norms for the scale, now called the Stanford Binet. IQs between 90 and 110 were considered average. Those below 70 were indicative of mental retardation.
Today, psychological tests are used to evaluate, not only cognitive abilities, but also personality, traits, interests, and occupational aptitudes. The ratio IQ has been replaced by more sophisticated, statistically derived scores based on the performance of thousands of people who have been tested. More emphasis is placed upon specific abilities than overall IQ. Testing has become a big business. It all began with Binet.