The IQ and Intelligence

IQ: Nature versus Nurture

The debate over IQ and intelligence really starts with the debate about nature versus nurture, so let us begin there, too. Some people believe that a baby is born with certain characteristics. In the middle ages in Europe, people believed that babies were born with original sin.
 Original sin is a Christian concept created by the early Catholic church to explain diversity. It states that the sin of Adam and Eve, the first earthly parents, has been passed on to subsequent generations. When children are born, they are already tainted by this curse. In other words, they are already imbued with evil.
 During the Renaissance in Europe, the concept of original sin was replaced with the believe that people were born with innate goodness. Both of these concepts—original sin and innate goodness—represent the nature side of the discussion.

The opposing view was first articulated by Rousseau during the Western epoch called the Enlightenment. This view is called "Tabula Rasa," Latin for "blank slate." People who subscribe to this theory maintain that babies' minds are blank slates, to be written on by the environment. This is the nurture side of the debate.

Definitions of Intelligence

But what is intelligence?. Sattler describes a famous symposium conducted in 1921 at which 13 psychologists gave 13 different definitions of intelligence (1992, pp. 44-45). Some of these definitions are paraphrased below:
 Intelligence is. . .
the tendency to take and maintain a direction. . .
judgment, otherwise called good sense, practical sense, initiative. . .
everything intellectual can be reduced to . . . relations or correlates. . .
adjustment or adaptation to the environment. . .
global capacity to act purposefully, think rationally, and deal effectively. . .
the ability to plan and structure behavior. . .
the process of acquiring storing, retrieving, comparing memory. . .
the ability to solve genuine problems or difficulties. . .

You can see that we still have not reached a common definition. However, researchers have obtained a high degree of consensus on the common elements of intelligence. Three behavioral descriptors were rated as critical by 96% of the group of over a thousand professionals. These include abstract thinking or reasoning, the capacity to acquire knowledge, and the ability to solve problems.

Lumpers define intelligence as a general, unified capacity for acquiring knowledge, reasoning, and solving problems (Weinberg, 1989). Galton, for example, first proposed that individuals possessed a general intellectual ability, which he called the "g" factor. This capacity may be demonstrated in different ways, such as navigating without a compass, programming a computer, or memorizing the Koran.
 Splitters maintain that intelligence is composed of many separate mental abilities that operate more or less independently. One splitter, Harold Gardner, has identified seven different types of intelligence. These include linguistic, logical/math, verbal/spatial, musical, bodily/kinesthetic, interpersonal, and intrapersonal abilities.
 There are other approaches to intelligence. We have studied Piaget, who believed that intelligence represents the biological adaptation of an individual to the environment. Piaget suggests that intelligence increases as children develop, especially from birth through age five. In a work questioned by many (Ogbu, 1974, 1978), the controversial Arthur Jensen suggested that race determines intellectual ability (1969).
 Cattell and Horn have developed an innovative approach to the structure of intelligence. They propose two types of intelligence, fluid and crystallized. Fluid intelligence refers to essentially nonverbal, relatively culture-free mental efficiency. Crystallized intelligence refers to acquired skills and knowledge that are strongly dependent on exposure to culture. These authors argue against. "g" intelligence.

Other kinds of intelligence might include social intelligence—the ability to get along well in society (Taylor, 1990) and survival intelligence—the ability to survive. Certainly the ability to survive in a wilderness will be different from the ability to survive in an inner city, but I expect both call for similar capabilities.
 Sternberg's triarchic model helps us examine intelligence as an information-processing model. This group of theories focuses on the ways that people perceive, store, retrieve, and manipulate information, including thoughts, feeling, and actions. Information-processing theories often compare the human brain to a computer.

Sternberg has identified three types of intelligence: componential, experiential, and contextual. His model fits well with the systems approach we have been studying in this class. It is built on three principles:
First, intelligence cannot be understood outside of a sociocultural context.
Second, Intelligence is purposeful and goal directed, and consists of two general skills:. the ability to deal with novel tasks and the ability to learn from experience to perform routine tasks effortlessly or automatically. In this class, I want you to learn to use the computer and to express yourself through written work effortlessly—spend time on grammar now so you will not have to worry about the mechanics of written communication later. In other words, you will free up your brain to handle new problems and learn from experience.
Third, intelligence depends on acquiring information-processing skills and strategies.

Current theories of intelligence combine several of these views (Bronfenbrenner & Mahoney, 1975). Most stress at general factor at the top of the hierarchy, several broad classes of abilities in the middle, and primary factors at the bottom. Genetically determined mental ability is always seen as being modified by experience; and measures of IQ are seen as somewhat arbitrary summary indexes of many abilities.

The following statement was written by a man classified as mentally retarded. He was studying Thoreau’s Walden. When asked to go outside and find something that reminded him of that classic book, he noticed a cricket. Though his academic ability is limited, this young man’s wisdom is evident in this passage.
Mother Nature wants us to get something out of everything. I get out of a cricket is it tries to live out its life but sometimes someone comes allong and steps on it and kills it. It happens in our life. We mite not be dead philisicly or mentaly but every times a little hatred comes along it kills us spritually. If we could be nice to each other their would not be a lot of "dead" people walking in the world.

IQ Is What IQ Tests Measure 

In school settings, psychologists often joke that IQ is what IQ tests measure. There is a lot of truth to this adage. Ideally, IQ tests sample a wide range of experiences and they measure a person’s ability to apply learned information in new and different ways. They do not measure capacity or potential. They do provide information about cognitive skills at a given point in time.

Because IQ tests chiefly measure success in school, they are value-laden. Scores provide a statistical indication of the extent to which a person has critical schools and information, but they should not be directly equated with intelligence. Test scores are a useful index of ability, but they may reflect test-taking sophistication, personality, and attitudinal characteristics as well as learned and innate ability (Plomin, 1989).

History of Intelligence Testing

The struggle to measure intelligence began during the last portion of the last century. It paralleled Freud's investigation into our emotional development. One of the first people to systematically study intelligence was Alfred Binet of France. At that time, French schools were over-crowded. This charge was to develop a test that would weed-out the less able students. The 1905 scale he developed is, for all practical purposes, the first intelligence test.

The Binet scale has been modified many times. In 1916, it was amended by Lewis Terman from Stanford University. This resulted in the first Stanford-Binet Scale. The most recent revision was published in 1986. The Stanford-Binet remains one of the most widely used measure of intelligence. In South Carolina, for example, it is the only test considered acceptable by law for placing children in special educational programs.

The Stanford-Binet differed from earlier tests in that is showed some concern for age. Following Stern's hypothesis of a mental quotient (1914), Terman coined the phrase IQ, an acronym for Intelligence Quotient. The intelligence quotient is found by dividing the mental age (test score) by the chronological age and multiplying by 100.

IQ = (MA / CA) X 100

Average mental age (MA) scores correspond to average chronological age (CA) scores. A "normal" person would have an IQ of 100. Bright children attain higher scores, while dull children attain scores lower than 100. The normal distribution or range of scores is illustrated in your text.

Another approach to testing was taken by David Wechsler. Wechsler was selected 11 different subtests to form a scale. Eventually he developed three tests of intelligence:. The Wechsler Intelligence Scale for Children-Revised (WISC-R); The Wechsler Preschool and Primary Scale of Intelligence (WPPSI); and the Wechsler Adult Intelligence Scale-Revised (WAIS-R).

Wechsler's search for subtests was guided by his belief in the global nature of intelligence. He considered intelligence to be part of the large whole of personality. He did not design the subtests to measure primary abilities. He chose tasks which could capture the total range of abilities in that global concept called intelligence.

The Wechsler model is based on factor analysis, a complex computer-based process to complicated for us to study here. For each subtest, the actual score is compared with age-based norms and an age-appropriate score is derived. The derived scores are summed for a total IQ score. The average IQ in this model is 100, with a standard deviation of 15. The Wechsler tests are the tests most commonly used in North Carolina.

IQ tests Compared with Other Tests 

IQ and achievement tests. Achievement tests measure the amount of information that has been acquired through study. IQ tests differ from achievement tests in that IQ are not dependent on formal learning acquired at school or at home. Test creators strive to develop IQ instruments that are culture-free, although this goal may be unattainable in a multicultural society such as ours.

Criterion-referenced and norm-referenced tests. Criterion-referenced tests identify an individual’s performance by comparing it with an established standard. It compares levels of mastery rather than scores. Criterion-referenced tests help educators make instructional decisions. For example, a child’s performance can be described in relations to established benchmarks. Children who have mastered first-grade material are ready to move to second grade. Those who have not need more work at the current level.

Norm-referenced tests compare an individual’s performance in relation to the performance of others on the same measure. Usually the individual is matched to the group in some way such as age, sex, socio-economic status, or primary language. IQ tests are norm-referenced tests.

In order to be valid, each of these types of tests must be administered in a standardized setting. That means the setting, instructions, and timing must be equivalent for each test administration, and the score is only as reliable as the administration of the instrument (Gould, 1992).

The different types of IQ tests discussed above yield different scores and these scores are not interchangeable. In addition, no one intelligence test measures the entire spectrum of abilities related to intellectual behavior. Some measure creativity, others examine verbal and quantitative skills, while still others look at mechanical ability. Even a complex battery of tests cannot give a complete picture of any person’s abilities, for tests only sample the individual’s repertoire of skills.

IQ Testing: Pro and Con

There are serious and significant advantages and disadvantages to the testing movement (Sattler, 1992). These are summarized below:






The IQ has a larger collection of correlates predictive of success in a wide variety of human endeavors than does any other variable. Intelligence tests limit our understanding of intelligence and sample only a limited number of conditions under which intelligent behavior is revealed.
Intelligence testing in the primary leveler preventing the classes from hardening into castes. IQs sort children into stereotypical categories and limit their freedom to choose fields of study.
Intelligence testing has revealed unsuspected talents in many individuals and has improved educational opportunity. Knowledge of their IQs may inhibit children’s level of aspiration and affect their. self-confidence.
Intelligence tests provide standardized ways of comparing children’s performances. Intelligence tests fail to measure underlying processes.
IQs may measure a child’s ability to compete economically and socially.  IQs are misused as measure of innate capacity.
IQ tests provide a profile of strengths and weaknesses. IQ tests do not do justice to the multi-dimensional nature of intelligence.
IQ tests are excellent predictors of scholastic achievement. IQs are limited in predicting occupational success.
The IQ measures the effects of special programs, treatments, and training. The IQ cannot predict nonacademic intellectual activity.
IQ tests assess individual differences.  
IQ tests are biased against ethnic minorities.
Intelligence tests are valuable tools in working with handicapped children. Nonconventional, original, and novel responses are penalized on IQ tests.



Bronfenbrenner, U., & Mahoney, M. A. (Eds.) (1975). Influences on human development (2nd ed.). Hinsdale, IL: Dryden Press.
Gould, S. J. (1992). The mismeasure of man. New York: Norton.
Jensen, A. R. (1969). How much can we boost IQ and scholastic achievement? Harvard Educational Review, 39(1), 1-123.
Ogbu, J. U. (1974). The next generation: An ethnography of education in an urban neighborhood. New York: Academic Press.
Plomin, R. (1989). Environment and genes: Determinants of behavior. American Psychologist, 44(2), 105-111.
Sattler, J. M. (1992). Assessment of children (3rd ed.). San Diego, CA: Author.
Taylor, E. H. (1990). The assessment of social intelligence. Psychotherapy, 27(3), 445-457.
Weinberg, R. A. (1989). Intelligence and IQ: Landmark issues and great debates. American Psychologist, 44(2), 98-104.