Theories of Intelligence:

Are There Different Kinds of Intelligence?

Early on, psychologists thought of intelligence as a general- ized factor, a g-factor. Your g-factor would include all the aspects of intelligence mentioned in the definition we gave above. The earliest intelligence tests were based on this point of view. Today, however, psychologists are more inclined to see intelligence as multidimensional.

In this context, some psychologists differentiate fluid intelligence and crystallized intelligence. The former has to do with information-processing abilities, reasoning, and memory. The latter has to do with accumulated information, learned skills, and strategies for solving problems.

Another approach, developed by psychologist Howard Gardner, maintains that there are multiple intelligences. These include the following:

Musical intelligence differentiates a Mozart from one who can read music but can't carry a tune or keep the beat.

Body-kinesthetic intelligence differentiates Tiger Woods from the weekend duffer. The professional dancer, the NFL quarterback, and the Olympic gold medalist rate high in this kind of intelligence.

Logical-mathematical intelligence permits a few to grasp the solution to an equation while someone else is still copying it from the blackboard.

Linguistic intelligence shines bright among the most skilled word-crafters. A great poet gets to the roots of things and spins deep insight from the play of language. A great novelist breathes life into imagined characters and allows us to explore the sights and sounds of times long past.

Spatial intelligence rose to amazing heights in the mind of whoever imagined and then guided the creation of the Great Pyramid at Giza.

Interpersonal intelligence is the gift of compassionate empathy that sees into the heart and mind of friend and foe alike.

Intrapersonal intelligence reveals the depths of a heart and mind that has marched far down the path of
self-knowledge.

Naturalist intelligence is the ability to identify and classify patterns in nature. Most people on a nature hike through a forest see lots of leaves. A few, who are high on naturalist intelligence, see distinct differences between many kinds of leaves.

Gardner's multiple intelligences work together. The great athlete may inspire teammates by way of interpersonal intelligence. The spatial intelligence of the accomplished architect interacts with his or her naturalistic and logical- mathematical intelligences.

Practical Intelligence and Emotional Intelligence

Robert Sternberg's work sharpens the concept of intelligence in an interesting way. Noting that most measures of intelli- gence don't correlate very well with career success, he would have us consider the concept of practical intelligence. By contrast with academic intelligence, practical intelligence is based on the ability to observe and understand other people's behavior. Consider any organizational ladder to success and notice this: The rungs of the ladder are neither facts nor skills-however much these may be helpful. The "rungs" are people. If you don't know what your boss expects, nothing else you know will get you another step up the corporate

ladder. If you don't understand the norms and the culture of the company you work for, you're likely to remain a stranger in a strange land.
Related to practical intelligence is emotional intelligence. The elemental skill of emotional intelligence is impulse control. High school-level emotional intelligence allows you to tune in to the thoughts and feelings of others. Graduate-level emo- tional intelligence allows you to get along with all kinds of people under all kinds of circumstances.

Assessing Intelligence

For example, intelligence is a concept that can be opera- tionally defined. We define intelligence in terms of a high intelligence quotient (IQ) score (or by an impressive ability to correctly answer Jeopardy! questions). Psychologists attempt to create useful and reasonable operational definitions for intelligence.

In science, an operational definition states the specific actions or procedures used to measure a concept. Operational definitions of intelligence have been widely expressed by two popular IQ tests. The two tests are the Stanford-Binet Intelligence Scales and the Wechsler Intelligence Scales (there's a separate Wechsler Scale for adults and for children). The Stanford- Binet was first used to test schoolchildren. It assessed intellectual performance by comparing actual age to mental age. Mental age is the level of intellectual performance expected at any given age. The Stanford-Binet IQ score is derived in this way:

mental age (MA) ÷ chronological age (CA) × 100 = IQ score

We multiply the ratio MA/CA by 100 to derive a standardized score. For example, if Jody has a chronological age of 8 and a mental age of 10, his IQ equals 10 divided by 8, or 1.25.

We would then multiply Jody's score by 100, making his IQ score 125. That score is considered well above average.

Why? The average of all score values of MA/CA for the general population is determined by an equal ratio of MA/CA, which would equal to 1/1. When that ratio is multiplied by 100, the answer equals 100. Therefore, 100 is the average expected IQ score for the general population.

Most IQ tests set the average IQ score at 100. That figure is based on the assumption that, in a general population, IQ measures will follow what's called the normal curve or bell curve.

Today, forms of the Stanford-Binet are used for adults. However, the most widely used IQ test for adults is one of the Wechsler Scales. (As noted in your text, there are actually several variations of the Wechsler IQ tests.)

Variations in Intellectual Ability

Mental retardation indicates a disability in learning, develop- ment, or behavior. Cases of mental retardation can range from mild to severe.

While low IQ scores generally indicate this disability, other factors-such as performing everyday tasks like getting dressed-also play a role in determining mental retardation. You should keep in mind that the men- tally retarded aren't normally disabled where feelings are concerned.

They might not have the same mental capacity as other people, but they do experience the same feelings and emotions.

Your textbook points out several factors that may cause men- tal retardation, suggesting that mental retardation might be preventable in certain cases. For instance, since retardation often occurs as a result of fetal damage, as in fetal alcohol syndrome, it would make sense to ensure that pregnant mothers have adequate diets and that they abstain from drugs and alcohol. Evidence also confirms that exposure to toxins in early childhood may be a cause of mental retarda- tion, so avoiding exposure to toxic substances would be an obvious preventative measure for mental disabilities. It's also important to note that some causes of this disability-like genetic abnormalities, as in familial retardation-aren't preventable.

The best studies suggest that people with higher IQs are more likely to be successful and satisfied with their lives. Studies like those conducted by Lewis Terman reject the notion that very bright people are hampered by their intellect and are incapable of common sense. Additionally, people with high IQs use their intelligence in different ways. Though she has the highest IQ ever recorded, Marilyn vos Savant hasn't contributed substantially to the arts or sciences. By contrast, theoretical physicist Murray Gel-Mann had only a modestly high IQ, yet his scientific contributions revolutionized the field of quantum physics.

Debates continue about the accuracy and fairness of intelli- gence tests. A popular question centers on how appropriate IQ tests may be for people raised in different cultures. Given that the United States is a land of immigrants, much atten- tion has been given to developing culture-fair tests. These tests attempt to measure intelligence without being affected by the person's cultural experience or background.
When you read about how heredity and the environment affect intelligence, you should note two things. First, studies of identical and fraternal twins support the importance of genetic makeup in determining eventual adult IQ scores within certain limits. Second, other research suggests that a child's environment may have a marked influence on a child's IQ score. As the debate over heredity and environment contin- ues, most psychologists now admit that intelligence is a product of the interaction of environment and one's genetic inheritance.