What is Intelligence?


“Intelligence is the ability to face problems in an unprogrammed (creative) manner.”

— Stephen Jay Gould

“The Mismeasure of Man”

Ever since “The Bell Curve” came out a few years ago, there has been more than the usual amount of controversy about intelligence: what it is, whether it can be measured, how much is inborn, and whether it varies by race or group. For perspective, let’s take a quick look at the development of thought in this field.

The first intelligence test for school children was developed in Paris by Alfred Binet between 1905 and 1911. It was adapted by Stanford psychologist L. M. Terman (1877-1956) as The Stanford-Binet test, and termed an intelligence quotient (IQ) test. It was the first important test, has been revised through the years, and is the one most widely used.

Two British psychologists were also quite influential. Cyril Burt (1883-1971) and C. E. Spearman (1863-1945) both supported two principles: (1) intelligence is a single, measurable entity, and (2) it is innate and unchangeable. University of Chicago psychologist L. L. Thurstone (1887-1955) disagreed, contending that there were 7 primary mental abilities: verbal comprehension, word fluency, computational ability, spatial visualization, associative memory, perceptual speed, and reasoning. Another psychologist (Guilford) found 120 types of mental abilities.

Now into this fray springs Stephen Jay Gould, a contemporary Harvard scientist and prolific science author. He says, in effect, a pox on all your houses — intelligence can not adequately be measured: “The very fact that estimates for the number of primary abilities have ranged from Thurstone’s 7 or so to Guilford’s 120 or more indicates that vectors of mind may be figments of mind.”

Though well-informed and persuasive, Gould is at odds with mainstream psychologists, who (in a statement signed by 52 psychologists, published in the December 13, 1994 Wall Street Journal), contend the following:

1. Intelligence exists as a very general mental capability involving ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly and learn from experience. The brain processes involved are little understood.

2. Intelligence can be measured, and IQ tests measure it well. Nonverbal tests can be used where language skills are weak.

3. IQ tests are not culturally biased.

4. IQ is more strongly related than any other measurable human trait to educational, occupational, economic, and social outcomes. Whatever it is that IQ tests measure, it is very important.

5. Genetics plays a bigger role than environment in intelligence, but environment has a strong effect.

6. Individuals are not born with an unchangeable IQ, but it gradually stabilizes during childhood and changes little thereafter.

The psychologists also make some generalizations about IQs by race, but they may mean little. Gould says “All modern human races probably split from a common ancestral stock only tens of thousands of years ago.…The overall genetic differences among human races are astonishingly small.”

Now, just for fun, let’s take Thurstone’s 7 abilities and arrange them in order of importance to risk managers. Here is my hierarchy:

1. Reasoning

2. Associative memory

3. Computational ability

4. Verbal comprehension

5. Perceptual speed

6. Word fluency

7. Spatial visualization

You might wonder why I put computational ability as high as #3. I include with that an ability to understand the relative importance of numbers and statistics — a quality essential to sound risk management, and which may be the weakest quality of many current risk managers. What do you think?