Defining Intelligence (Part 2) – the Dreaded IQ test

Honestly, this has been one of the hardest posts to write because the abundance of hype, craze, scientific jargon and mathematical terms related to the subject of Intelligence Quotient (IQ).  So let’s take a more tongue-in-cheek look atthis otherwise really boring yet still controversial subject.

IQ is a score derived from one of the standardized tests designed to assess intelligence. There are at least 6 credible tests that are being used currently include Wechsler Adult Intelligence Scale, Wechsler Intelligence Scale for Children, Stanford-Binet, Woodcock-Johnson Tests of Cognitive Abilities, Kaufman Assessment Battery for Children, and Raven’s Progressive Matrices. So you can take all 6 and brag about the highest score on the “official test” at the next networking event! However, if you have 6 low scores, read on – I will show you how to “defeat” every IQ test elitist that talk about his/ her scores.

When modern IQ tests were constructed, the average score within an age group was set to 100 and the standard deviation (SD) or intervals set to 15. For example, 85-100 will be one interval; 100- 115 will be another.  Approximately 95% of the population scores between 70 and 130. Also, two-thirds of the populations have IQ scores within the range 85-115. These numbers practically mean nothing because every IQ test converts the raw scores into a standard bell curve!

Rising IQ?  The average IQ scores for much of the population have been rising at an average rate of three points per decade since the early 20th century, a phenomenon called the Flynn effect. It is disputed whether these changes in scores reflect real changes in intellectual abilities. In plain English, we know the IQ scores are going up; but we don’t know if it really means we are getting smarter! It does not help that on modern tests, the standard error of measurement is about 3 points. In other words, there is a 95% chance that the true IQ is in range from 4-5 points above OR below the test IQ. Here goes our Flynn effect!  To be fair, Flynn effect has prompted much new research in psychology and “demolish(ed) some long-cherished beliefs, and raise(d) a number of other interesting issues along the way” according to 1998 article in IQ and Human Intelligence.

IQ test may actually be based on an outdated methodology.  A 2006 article stated that contemporary psychological research often did not reflect substantial recent developments in psychometrics and “bears an uncanny resemblance to the psychometric state of the art as it existed in the 1950s.”

Is IQ score even an accurate measure? It may surprise you to know that scientists are divided on the issue of whether or not IQ tests are an accurate measure of intelligence. It is difficult to define exactly what constitutes intelligence; it may be the case that IQ scores represent ONLY a very specific type of intelligence.

Alfred Binet, a French psychologist who developed the first IQ test, did not believe that score can be used to measure intelligence. He stated in 1905 that IQ score  “does not permit the measure of intelligence, because intellectual qualities are not superposable, and therefore cannot be measured as linear surfaces are measured.”

Binet had designed the Binet-Simon scale in order to identify students who needed special help in coping with the school curriculum. He argued that with proper remedial education programs, most students regardless of background could catch up and perform quite well in school. He did not believe that intelligence was a measurable fixed entity. I can sincerely say that Binet was a scientist after my own heart or maybe it is the other way around.

How we have been using these not so reliable IQ scores? IQ scores have been shown to be associated with such factors as morbidity and mortality, parental social status, and, to a substantial degree, parental IQ.  After close to 100 years of research, researchers can only conclusively point to a strong positive relationship between parent’s and child’s IQ.  We are not sure what that positive relationship means or how significant it is, or if IQ can be inherited, and if it is “inheritable”; we are clueless on how it takes place.  

Psychologist Peter Schönemann was also a persistent critic of IQ, calling it “the IQ myth“. He argued that IQ is a flawed theory and that the high heritability estimates of IQ are based on false assumptions. There is also the issue of test-bias. A 2005 study stated that “differential validity in prediction suggests that the WAIS-R test may contain cultural influences that reduce the validity of the WAIS-R as a measure of cognitive ability for Mexican American students,” indicating a weaker positive correlation relative to sampled white students. (Basically, Mexican-American students are found to score lower on this type of IQ test due to test questions’ inherent cultural context.)

So, you can stop any IQ-score-elitist dead in his tracks by saying: “I found it difficult to trust my own high IQ scores considering tests are based on outdated methodology as well as a questionable measurement of intelligence and the scientific community still cannot come to an agreement on an interpretation.” And smile.


Defining “Intelligence” – a controversial saga (part 1)

Defining “Intelligence” is a controversial saga that is more entertaining than day-time soap.  In 1994, a group of academic researchers in fields allied to intelligence testing issued a public statement “Mainstream Science on Intelligence.”  This documents, originally published in Wall Street Journal,  documented key conclusions widely accepted in the expert community. (It was a response to what the authors viewed as the inaccurate and misleading reports made by the media.)  52 university professors specializing in intelligence and related fields, including one-third of the editorial board of the journal Intelligence, signed the open letter.

But the public drama of scientists vs. media didn’t stop there. The letter to the Wall Street Journal also set out 25 conclusions.  There is a short summary of several that most people would consider controversial statements about race, genetics and intelligence.  Mis-quoted or worse, purposefully mis-communicated with malicious intent, these could be really damaging statements.

  1. “The bell curve for whites is centered roughly around IQ 100; the bell curve for American blacks roughly around 85; and those for different subgroups of Hispanics roughly midway between those for whites and blacks. The evidence is less definitive for exactly where above IQ 100 the bell curves for Jews and Asians are centered”
  2. “… genetics plays a bigger role than environment in creating IQ differences”
  3. “Racial-ethnic differences in IQ bell curves are essentially the same when youngsters leave high school as when they enter first grade … black 17-year-olds perform, on the average, more like white 13-year-olds”
  4. “Almost all Americans who identify themselves as black have white ancestors – the white admixture is about 20% … research on intelligence relies on self-classification into distinct racial categories”

Not to be outdone, American Psychological Association rushed unto the stage. Intelligence: Knowns and Unknowns was a 1995 report issued by an 11-expert task force created by the APA. (3 were signatories on Mainstream Science on Intelligence.)  Concerned about “…research findings were often assessed not so much on their merits or their scientific standing as on their supposed political implications,” the task force decided on the following definition:

Individuals differ from one another in their ability to understand complex ideas, to adapt effectively to the environment, to learn from experience, to engage in various forms of reasoning, to overcome obstacles by taking thought. Although these individual differences can be substantial, they are never entirely consistent: a given person’s intellectual performance will vary on different occasions, in different domains, as judged by different criteria. Concepts of “intelligence” are attempts to clarify and organize this complex set of phenomena. Although considerable clarity has been achieved in some areas, no such conceptualization has yet answered all the important questions, and none commands universal assent.

One thing worthy to note in the length APA paper, task force did not include the idea that genetics play a significant role in the appearance of between-group differences in IQ.  Some people feels APA merely side-stepped the issue by passively omitting the wording of the statement. This group would love to see APA declare strongly that race/genetic/heredity is NOT a factor so no one can read in between the lines.

Who knows science can be this much fun?  Next up, we will tackle the 5 or 6 or 7 major intelligence theories. (Hint, no body can seemed to agree on the number.)