9.35 Secrets of the IQ. What is Intelligence?

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35. Intelligence and the IQ (Update 19 Septr 2021)
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The Intelligence Quotient or IQ?

The IQ 3-digit number is arithmetically inaccurate

racial eugenics

“Intelligence quotient” subtly changed the meaning of “intelligence,"

David Wechsler and the modern IQ

Wechsler IQ starts & ends with the bell curve

Does familiarity with IQ test increase one's IQ score?

What is the Practical Meaning of IQ?

Is IQ Inherited?

What of Recent Data on IQ and Race?

Usefulness of the IQ

“low IQ” does not equate with “stupidity.”

“idiot savant,”

Genius

IQ Testing and You

My advice for parent wishing to use IQ testing to assist a child

Best Condition for IQ test-taking

The Intelligence Quotient, or IQ? The testing originated in Paris c.1900 to detect school dropouts in order to give them better teaching. The first test, 30 questions of increasing difficulty, was tried on normal school children and on same-age mildly retarded ones. Researchers found a reproducible number of correct answers for each age in normal children (e.g., 6 y/o's averaged 15 correct answers; 7 y/o's, 18 correct; 8 y/o's, 21). Followup showed a child scoring below the age norm was high risk to drop out.

   "Intelligence Quotient" entered our language in 1912 when the test got to America. The raw score gave the mental age (MA), the measure of how a person taking the test performed compared with same-age test-takers in number of correct answers. For example, if a 6 y/o made the same number of right answers as was average for a standard sample of 8 y/o's but not for 9 y/o's or higher age, that child would be assigned an Mental Age, or MA, of 8. And since his real age was 6, it was catchy to represent how well or poorly he did compared to the average for his age by dividing his MA by Chronological Age (CA). In the example, it is 8 divide by 6, giving a quotient of 1.33. Multiply by 100 and you get Intelligence Quotient, or IQ 133.
The IQ 3-digit number is arithmetically inaccurate. A number generated by a ratio like MA/CA x 100, where the MA or CA value is double-digit can only generate an IQ of double-digit significance (i.e., IQs from this computation should only have been expressed as 10, 11, 12). Practically that would have meant all IQs should have been rounded to nearest 10s (all scores between 116 and 124 as 12). With ages below 10 even that is one too many digits since CA becomes single digit. And CA is not as digital as the bare number made it appear; rather, it is more analog continuous if one factors the months of age into an individual child's CA (e.g., a 10 year, 6 month old child actually has CA of between 10 and 11, and not 10 as is used in the IQ). This becomes even less accurate when one considers that many children are born prematurely by up to 2 months, which affects mental age development that cannot be expressed in CA number as an integer (e.g., two 10 y/o's, one born 2 months premature do not have the same CA 10 that is used to compute each one's IQ). Finally, as any teacher knows, kids develop mentally at differing rates and that may even continue into adulthood, which confounds the idea of a fixed IQ at any age.

   The IQ's arrival in America coincided with World War 1 and a racial eugenics idea. When IQ tests were administered to 2-million US Army recruits in 1916-18 and showed slightly inferior scores for Blacks compared to Whites, the test became another excuse to treat Blacks as inferior.

   “Intelligence quotient” subtly changed the meaning of “intelligence,” which had been a word for higher mental activity. IQ changed it into an innate, fixed capacity. The IQ placed one's intelligence as an exact 3-digit number by which a person seemed to be ranked in mental worth (e.g., if I have IQ 105 and you have 101, I'm smarter than you). 

 It brings us to David Wechsler and the modern IQ.

David Wechsler (b. 1896 in Romania, d. 1981 in USA) was born in the year that work began on IQ. And his psychology degree came just as the first IQ tests developed. Wechsler was drafted into the U.S. Army and supervised new Army IQ testing. And this son of non-English speaking immigrants early-on faced the practical problem of giving IQ tests to the culturally deprived.

   After the war, Wechsler made the ideal intelligence test that would solve problems of IQ testing as he saw them in 1920 – statistical flaws, cultural bias, and racism. He became Chief Psychologist of New York City's Bellevue Hospital in 1932 and held it until retirement in 1967, 35 years during which various versions of Wechsler IQ tests became standard.
   Wechsler made 3 contributions: He discarded MA/CA=IQ, substituting for it a statistical method of test scoring; he attacked the problem of cultural bias by introducing “performance IQ” as balance against verbal IQ; and he introduced the idea that IQ test could measure and localize brain abnormalities, making it a diagnostic tool in dementia, for brain tumor, and in stroke prognosis.

   The richer content of the Wechsler tests makes cultural bias less likely. The verbal test is given in subsets: Information, Comprehension, Arithmetic, Similarities and Digit Span. The performance test has the sub-tests Block Design, Picture Completion, Picture Arrangement, Object Assembly and Digit Symbol. The tests are continually revised based on feedback from the huge testing population. Score is reported as Verbal IQ (VIQ), Performance IQ (PIQ) and Full Scale IQ (FSIQ)                   

Wechsler IQ starts & ends with the bell curve. In developing a test, the same test is administered to sample populations, selected so as to be a representative mix in sex-ratio, geographic distribution, race, ethnicity, and economic level. Same test is taken by all and raw score made in numbers of correct answers. After raw scoring, a frequency distribution graph (the curve) is constructed separately for each age group. (For children, in each single-year age group; for adults, in five-year successive age groups.) In all age groups the bell curve is produced. Although the curve is similar (bell-shaped) for all groups, the number of correctly answered questions varies in frequency. For example, in test results from 10 y/o's, 253 correct answers represent the 50% point (median), which is the peak of the bell, and is given a test IQ score of 100 for the 10 y/o's. From 12 y/o's, 265 correct represents median and that is the IQ of 100 for the 12 y/o's. And across whole range of age groups from 4 to 74, an IQ of 100 is assigned to the test-taker who makes the median number of correct answers within his age group.

Does familiarity with IQ test increase one's IQ score? The test authority says it does not, but the popularity of the late Stanley Kaplan's prep course suggests it does.

What is the Practical Meaning of IQ? Does IQ really measure intelligence as a measure of the brain's efficiency? Or does it more often measure motivation, test-taking opportunity, cultural advantage and skill at memorizing? And how relevant are IQ scores to success in life?  Research studies show that, on average, an IQ of 90 or below is associated with a less productive, successful life than an IQ of 100 or more. 
My observations are that IQ number measures a combination of motivation, prior test-preparation experience, cultural advantage as well as basic brain power. The full Wechsler IQs are a best measure but even these should not be taken as pure intelligence gradings. For that we need a wider evaluation that can only be done on a one-to-one basis by a trained IQ psychologist looking at the tested subject's life, accomplishments and oral repartee.

Is IQ Inherited? Best studies involve identical twins. Twin studies suggest 50% input from genes into IQ score. But an important environmental influence is the birth experience. Lack of oxygen in fetal and newborn brain due to complicated pregnancy, premature birth, and birth trauma are well-known causes of lower IQ. Less known are virus illnesses, toxic drug effect and radiation (X-rays, natural and medical radioactivity and even UV rays during pregnancy). And, maybe, MRI magnetism effect during pregnancy or first 10 years of life?

   Geneticists who have studied IQ inheritance have ruled out simple type of single-gene dominant or recessive where high or low IQ mom or dad passes on low or high IQ to offspring. Instead, IQ inheritance are poly gene, the genes are estimated in the hundreds. This is important from standpoint of eugenic policy to improve IQ because it suggests genetically less “pure” individuals should tend towards higher IQ's because of greater input and variety of high IQ genes than purer (more inbred) racial strains, an idea that contradicts older, Nazi eugenics.

What of Recent Data on IQ and Race? A basic flaw in arguments about IQ and race relates to definition of race and to uncontrolled attempts to relate racial groups to comparative IQ scores. Some data have shown small average differences between Negro, Caucasian and Mongoloid (Oriental from Korea, China, Japan) race IQ. The small differences, however, tell nothing of cause. In the case of Black vs. White in USA, the slight on-average higher IQ score of Whites probably mostly reflects favored treatment of Whites. Also, both the Negroes and Whites do not represent pure race difference. Today's African Americans are a result of mating (mostly forced by White slaveholder raping slave) between White European immigrant, Negro slave and, to lesser extent, Native Amerindian. But not only African American! The American White today also carries a load of African Blacks' DNA, more or less, depending on geography. The only true, pure races are certain central African Negroes, the Brazilian jungle Amerindians, and Eskimos. The data on IQ and race or ethnicity suggest the best policy for upping IQ of all groups is equal opportunity, enriched education and racial or ethnic mixing.

Usefulness of the IQ  The Wechsler IQ is most useful for detecting children and young students who need an enriched teaching because they have been deprived of intellectual stimulation or have brain damage or brain mal-development. (The original purpose of IQ!) The IQ testing also can be used to measure educational effectiveness in schools or to measure trends of brain damage in geographic and national populations. And it has a use as part of the psychological profile in a mental health patient.

   The idea that someone having a “low IQ” equates with “stupidity” is simplistic. I have personal experience with a friend who scored low IQ as my childhood pal and now at age 88 is rather brilliant because of a life of good intellectual stimulation. And the attainment of a “high IQ” does not necessarily equate with intellectual brilliance or genius; it may simply be measuring a test-taking ability as a result of a Kaplan IQ-prep course, and in individual cases, it may be measuring speed of brain response which is lost in aging, or it may signal an “idiot savant,” a person with special retentive memory for test materials in a particular subject but who has no intellectual brilliance. Of course, there are lower levels of IQ, i.e., 85-90, below which one can always diagnose degrees of mental retardation but above that it becomes much less a quantitative measure of smartness.
    Genius can only be measured by the creativity that is shown by a person's ability at invention and production of new ideas. It is not, solely, based on an IQ test. A genius may score very high on the IQ but not always and though a high IQ score category (>150) is sometimes labeled “genius,” this is a misuse for a label that ought to be reserved only for proven inventive or creative-idea genius.

IQ Testing and You: For a child the indication for IQ testing should be poor performance or poor development that raises the question: mental retardation or not? If a child scores in retarded range, he should have neurological and psychological medical evaluation and, based on results, should be given enriched teaching appropriate to IQ and to his diagnosis. If a child scores normal or superior IQ yet is doing poorly in school, the adequacy of the teaching or the curriculum should be questioned and the stresses in the child’s school and home life checked. If IQ is dropping in successive tests in child or young adult, brain disease should be evaluated by Psycologic tests and by MRI and EEG.

   My advice for parent wishing to use IQ testing to assist a child's education is that IQ should be tested around age 10 and repeated once after an appropriate time interval (more than 1 year). An IQ drop of 10 points or more suggests neurological or psychiatric disease or a bad environment and these should be investigated, determined and corrected. A very wide range of the two IQ scores suggests that test-taking or the test taker's conditions varied and a 3rd test should be done after a year.
   IQ testing is not necessary for a normal child doing well at school.
   If at all possible, a child should not be told his IQ because that may have a limiting or a corrupting influence on his life. And one should not inform others of one's IQ because if high it suggests stupid boasting and if low it may prejudice others against the person with a lower IQ. And parents should not allow a high IQ score to cause them to treat the child in a special way. It is the low IQ score which calls for special improved education treatment.

Best Condition for IQ test-taking: Eat lightly in the morning and in the few hours before the test. Empty bladder before sitting to test. Do not take medicine day of test unless your doctor requires it. Be rested by having a normal night's sleep, or, if test in afternoon, rest in a one-hour repose in the few hours before test. Cancel the test if you feel ill.
      END OF CHAPTER. To read next click 9.36 Psychotherapy/Mostly Psychoanalytic