A child’s intelligence is measured by intelligence tests. These are a series of different tasks that the child has to solve at a certain age to some degree of accuracy, completeness and speed. The tasks in the tests are partly verbal, which means that the child must answer some questions or describe a picture, and in part they are non-verbal, meaning that the child does not have to say anything while solving tasks. The oldest test of intelligence is the Binet – Simon scale, which was compiled in 1904 and is still the most widely used in measuring intelligence in children.
Many authors have refined the original version of Binet-Simon’s scale, trying to adapt it to the specific characteristics of children aged 3-16 in individual countries. The most famous revision of the Binet – Simon test was performed in 1937 by Lewis M. Terman and Maud Merrill in the United States.
In addition to the Binet – Simon test, other series of tests are used. The Wechsler-Bellevue Test, Raven Progressive Matrices Test, the Human Drawing according to Goodenough-Harris and many more are used quite often. All of these tests can be applied in preschool or even school age. In young children, intelligence cannot be measured directly, but a conclusion is drawn on the extent of motor development at a given age; then the test scales used by Brunet, Gesell, Gesellu and other authors are used.
However, measuring intelligence in children in the first two years of life yields such uncertain results that have very limited practical value. The tests provide slightly more reliable data from the third year, when a Binet – Simon scale can be applied. However, based on the results of intelligence tests before the age of six years, no reliable forecast can be made for the child’s intellectual development. In early childhood, the IQ varies somewhat from year to year; even in school age it becomes more stable, and in puberty it becomes finite. That is why even school children can be sure of the extent of their mental development, which is important for planning their education, upbringing and social care.
The test results are not absolute indicators of children’s mental abilities. The results of a child’s self-testing are not only influenced by their intelligence, but also by other factors.
According to Davis A. and Havighurst R.J., these are the factors that affect a child:
- Degree of cultural development of the child’s environment, which affects how close the child is to the questions and problems posed in the test.
- The degree of skill with which the child solves tasks of a different intellectual nature.
- The degree of motivation in the child how to think about problems and how to solve them;
- The degree of speed of understanding the problem of the child, in making conclusions and making decisions.
The child intelligence examiner must consider all these factors when assessing the child’s level of intellectual development. Failure to do so will effect in poor results of less culturally developed children from the ones from culturally well-developed environment. The examiner must pay attention to the child’s current mental and health condition. If the child is sick, the test should be postponed until it has recovered. In a visually impaired or hearing-impaired child, this defect should be considered when evaluating responses.
A child’s intelligence test should be repeated for at least 6 months. If done earlier, the results will be unreliable, as the child may still remember the solutions to the test tasks. Test results can be repeated after one year if not for a longer time, especially when it comes to a younger child.
When all children in a given population are classified by the value of their IQ, it can be seen that the highest percentage – about a quarter have an IQ of 100. The higher and the lower IQs are classified around this middle value according to the normal distribution principle, i.e. in the form of a Gaussian distribution curve:
Examining 447 randomly selected children, Stevanović B. concluded that the middle value of their IQ was 102, and the range from-around to that value ranged from IQ 46 to IQ 146. Stevanović B.’s results show that very low intelligence occurs in children just as often as very high, however, the tendency of the trend is more often to appear higher than lower intelligence.