I often get calls from people who are interested in knowing what their IQ is, or what their child’s IQ is. There are various reasons that people want this information. Sometimes they just are curious as to where they stand in terms of intelligence. Sometimes they want this information to help them decide on academic, professional or career
Common questions are, “What is intelligence? How intelligent am I? How intelligent is my child? What is my I.Q. (intelligence quotient)? What is ‘social intelligence?’ What are street smarts?”
I.Q. (often abbreviated as IQ) is understood to mean a measure of intelligence. The term “intelligence quotient” comes from early intelligence tests for children that calculated an intelligence quotient by dividing the “mental age” score on the test by the child’s chronological age. Most modern intelligence tests do not use such a quotient, but still express test scores using the terms “intelligence quotient” and “IQ”.
When people express their ideas clearly and meaningfully, using a good vocabulary and proper grammar, and when they seem to be knowledgeable and well informed, we often regard them as “intelligent.” What we are reacting to is a good fund of general information, good verbal skills, and exposure to and mastery of “proper” Standard English (Or French, German, Spanish or any other language.)
A person’s fund of general information is in fact used as one element in the most widely used intelligence tests. However, what if this person is incapable of doing a simple math problem, or can’t find his way to the grocery store, or can’t learn how to use a computer or a remote control for a television set, or acts like a buffoon in social situations? Then we might revise our opinion of his intelligence.
Clearly, there is more than one type of quality that we identify as intelligence. There has been and still is an ongoing debate about whether there is such a thing as “general intelligence,” but how do we presently measure what we call intelligence in a meaningful and useful way?
There are many paper and pencil, self-administered or group administered tests that are called “intelligence” tests, but that do not do a good job of meeting acceptable criteria for an intelligence test. For example, we want an intelligence test to measure not just language and verbal skills, but also nonverbal skills and we want to have a reliable way to compare scores to the general population.
Psychologists generally accept certain standardized, individually administered intelligence tests as constituting our best present measure of intelligence. These are tests that measure various aspects of both verbal and non verbal intelligence. These tests include verbal, or language subtests such as general information, verbal abstract thinking, and arithmetic, and verbal attention span. In addition, they include as non verbal (or “performance”) subtests requiring the arrangement of colored blocks to match an abstract design, identifying missing parts in a picture and arranging a series of cartoon-like pictures to tell a logical story. Ten or more subtests, measures different areas of knowledge and performance are included in such tests.
These tests are also “standardized” in the sense that they have been administered to a representative sample of different ages of the general population. We then are able to compare the test results of one person with the scores of others of his or her own age, and assign a meaningful score (intelligence quotient, or IQ) to their performance on the test.
Examples of tests that meet these criteria and that are used as a standard test of intelligence by psychologists are the Wechsler Adult Intelligence Scale IV (WAIS IV) and the Wechsler Intelligence Scale for Children IV (WISC IV).
The scoring scales are constructed in a way that the average score at any age level is 100.
IQ scores are classified as follows:
| 130 and above: | Very Superior range | (2.2% of the population) |
| 120 to 129: | Superior range | (6.7% of the population) |
| 110 to 119: | High Average range | (16.1% of the population) |
| 90 to 109: | Average range | (50% of the population) |
| 80 to 89: | Low average range | (16.1% of the population) |
| 70 to 79: | Borderline | (6.7% of the population) |
| 69 and below: | Intellectually Deficient | (2.2% of the population) |
Many superficial “intelligence” tests that lack the validity, reliability, and proper standardization of the Wechsler Adult Intelligence Scale IV (WAIS IV) and the Wechsler Intelligence Scale for Children IV (WISC IV) use the same numbers ranges for so-called measures of IQ. Some yield grossly inflated IQ scores. If you have friends who tell you that they have an extremely high IQ such as 150, or that they test in the “genius” range, it is not likely that they have been tested on a standard intelligence test such as described herein.
Have you ever taken a proper intelligence test to determine your IQ? If you have not spent about two hours taking an individually administered test by a psychologist, testing a wide range of verbal and nonverbal areas of performance, the answer is, “No.”
Are intelligence tests culture neutral? Although psychologists try to construct these tests as culture neutral as possible, the above named tests have certain cultural biases. Some of the subtests are relatively less culture neutral than others. For example the Information Subtest has many items that assume knowledge of the history of the United States, whereas the Block Design subtest does not depend upon such culture specific knowledge.
What makes a person intelligent? We have some, but not all of the answers. We know that heredity plays a role. Intelligence does tend to run in families. Just as tall parents tend to have tall children, intelligent parents tend to have intelligent children. This is not surprising because we know that the brain is the organ that determines all aspects of mental functioning, including intelligence. Just as athleticism, height, weight, and skin color are determined partly by heredity due to physical attributes that we inherit, so is intelligence partly inherited. As with physical attributes, the degree to which we inherit this characteristic is determined by “a roll of the genetic dice,” resulting in a range of the inherited characteristic roughly distributed according to the familiar “normal,” or “bell shaped” curve. In plain English, this means that we don’t inherit the exact physical or mental characteristics of either parent. (Later address regression towards the mean). A familiar example of this variability is the fact that although most children of world class athletes inherit excellent athletic skills, only a few of them attain the extraordinary level of excellence that their parents achieved.
Does this mean that our intelligence is completely determined by heredity? Not at all. The development of all aspects of mental functioning, including intelligence also depends on what happen to the child from conception to adulthood. As with physical attributes, the development of intelligence can be crippled in utero by poor maternal nutrition, maternal illness or poor prenatal care. The healthy development of the brain and body both can be permanently crippled by poor nutrition before birth and during childhood.
In addition to the possible damaging effects of poor nutrition and disease, a lack of timely proper stimulation of the body and brain can impair the level of physical and mental development.
Contrariwise, a healthy physical and social environment can enhance the development of physical and mental skills. Parents intuitively talk to, hold and rock their infants, stimulating the development of hearing, speech, language and awareness of body position and gravity through input to the brain and equilibrium organs of the inner ear, respectively. Many studies have demonstrated that when babies are not stimulated by being touched, held, and talked to, their development is permanently and seriously impaired.
Therefore we can predict that when a child is exposed to the speech of educated and verbally accomplished adults, when parents read to their children, when a child grows up in a home where there are books and magazines, when a child sees his or her parents reading, when a child is provided with good academic training in a classroom situation that is conducive to learning, and when the family culture places a high value on learning, that child is likely to develop to his or her full intellectual potential.
When these positive conditions are lacking, we can predict that the child is unlikely to develop anywhere close to his or her potential. A potentially bright child may wind up functioning as an adult of low intelligence. For example the Roma (“gypsies”) in Ostrovany, Slovakia have lived segregated lives of poverty and their children have been sent to schools for the mentally handicapped, regardless of their intelligence. It is safe to predict that in adulthood people with such a paucity of learning experiences both at home and in school are likely to function at a low level of intelligence.
Can unfavorable early childhood learning experiences be overcome in later years? Even if the social environment changes favorably, it may be too late to recapture the child’s full intellectual potential after early years of learning deprivation. Because of the lack of proper mental stimulation early in life certain brain neural pathways fail to develop properly. An obvious example of the importance of proper early stimulation is obvious in language development. The language heard in the first few years of life shapes the sounds that a child speaks naturally. That is why learning the proper sounds of a language studied in later years represents such a challenge. The ultimate compliment to a person who has learned a new language after childhood is, “You sound like a native speaker.”
I do intelligence testing using the Wechsler Adult Intelligence Scale IV (WAIS IV) and the Wechsler Intelligence Scale for Children IV (WISC IV) at both of my office locations. I also do testing to evaluate memory impairment using the Wechsler Memory Scale, testing that measures important dimensions of reading, written language and math achievement using the Woodcock-Johnson III Tests of Achievement and testing for Attention Deficit Disorder at both locations.
Memory Impairment
Memory problems are a common concern for many people. Such problems can be caused by anxiety, depression, obsessive worrisome thoughts, a history of alcohol or drug abuse, or changes in brain function due to aging. Many people fear that memory lapses may indicate that they have Alzheimer’s disease, a progressive and devastating deterioration of memory functions. Fortunately, symptoms of memory impairment are more commonly manifestations or other, less serious problems.
Psychological testing can give us useful information about the status and quality of your memory functions. By comparing your scores to those of other people of your age we are able to determine whether there is really a significant problem in your memory functions.
One of the best tests available for this purpose is the Wechsler Memory Scale IV (WMS IV), a test that is composed of verbal and nonverbal subtests that measure both short term and long-term memory. Like the Wechsler Adult Intelligence Scale IV, this test is administered individually in a one-to-one setting. It takes about an hour and a half to administer this test. The results provide measures of several different types of memory functions.
As is true of intelligence, memory is a term that covers a wide variety of mental functions. For example, remembering a visual image, such as a person’s face, is different from remembering someone’s name. Remembering meaningful material, such as a story is different from remembering an abstract material, such as an address or phone number. For this reason, psychologists use tests that measure many dimensions of memory. As in the case of intelligence testing it is important to use a standardized test procedure that is the same for everyone, and to have norms that allow us to compare the results to other people of the same age.
Therefore, like intelligence tests, these tests are “standardized” in the sense that they have been administered to a representative sample of different ages of the general population. We then are able to compare the test results of one person with the scores of others of his or her own age, and assign a meaningful score that can be compared with the scores of others in order to determine the status of memory functions.
Learning Disabilities
The term “learning disability” applies when a certain areas of competence, such as ability to read, to master mathematics or to write is significantly below what would be expected on the basis of the person’s age, level of intelligence, and schooling. Learning disabilities tend to be quite specific. For example, someone may read and write very well, but have a terrible time learning even simple mathematics. Sometimes very bright people in technical fields such as engineering are excellent in higher mathematics, but are very poor readers. These differences appear to have something to do with differences in how our brains are structured and how our brains develop.
One key to making a proper diagnosis of learning disabilities is to make use of well-constructed tests of academic achievement in the specific areas of reading, mathematics and written expression. By comparing the level of achievement in these areas with the results of intelligence testing and by taking into account the educational opportunities and academic records of the individual, we are able to determine whether a diagnosis of learning disability is warranted.
As in the case of testing intelligence testing and memory function, it is critical that a valid, standardized test be used to measure various aspects of academic achievement, and that the results can be compared to a representative sample of people of different ages of the general population. The test that I use for this purpose is the Woodcock-Johnson Tests of Achievement, which provides measures of reading comprehension, reading fluency, mathematics calculations, applied mathematics, mathematics fluency, written expression, writing fluency and other measures relevant to assessing academic achievement.
Attention Deficit Disorders (ADD and ADHD)
Hyperactivity and problems in focusing one’s attention can also interfere with academic achievement, memory functions and the expression of intellectual potential. See the page on Attention Deficit Disorders for a discussion of this problem.