Another View of Social Rank and IQ
Richard Feynman's IQ, according to a Google search, is variously reported as 122, 123, 124 or 125; his sister's IQ is often publicized as one point higher than his. Based on no data whatever, I guess that the average IQ of contributors to Chance News (and possibly even the general readers of Chance News) is higher. With this in mind, perhaps it is time to call a moratorium on IQ reporting. Researchers, journalists and the general public never seem to get the picture right.
For example, in the New York Times of June 21, 2007, "The study found that eldest children scored about three points higher on I.Q. tests than their closest sibling. The difference was an average, meaning that it showed up in most families, but not all of them." The last sentence is a gratuitous comment to anyone who is statistically literate; the fact that the New York Times writer felt compelled to state it for his MSM audience speaks volumes about the level of statistical literacy in the United States.
Then, there is a tendency in the press to emphasize that these Norwegian results--the three point difference in favor of the first born--are not merely significant, but statistically significant, as if the adjective statistically is an intensifier, illustrating that try as we must, the distinction between statistical significance and practical significance is a losing battle with journalists.
But the major error made in the comments about the Science article and indeed, in almost every thing written about IQ, is the conflation of IQ with intelligence, as if the former is in one-to-one correspondence with the latter. The very first sentence of the Science article is "We have established a database in order to study the relations between perinatal factors and intelligence in adult age."
The readers of Chance News would do well to read Stephen Jay Gould's Mismeasure of Man for the unseemly history of IQ measurements from craniometry to the present-day tests. Along the way, females must be inferior because their heads are smaller than heads of males, Galton's use of physiological and reaction times as an indicator of intelligence and Terman's perversion of Binet's effort to identify children who needed help, and to provide that assistance. Terman introduced the notion of dividing a score by the person's age and thus, the "Q" for quotient. His followers, similar to a religious cult, truly believe that not only does IQ measure that vague concept known as intelligence, but moreover, strict rank order is in effect. An individual's weight, cholesterol, blood pressure or time to complete a marathon may vary but somehow the general public feels that one's IQ is fixed and immutable.
Notwithstanding the tenuous connection between IQ and intelligence, various explanations for the three-point difference are given both in the Science article and in reviews of the article. The best one may be found at one of Steve Sack's cartoons for the Minneapolis Star Tribune for June, 2007 (number 6) (http://www.startribune.com/sack/ . The top of the cartoon has "NEWS ITEM: SCIENTISTS PUZZLED AS TO WHY OLDER SIBLINGS SHOW HIGHER IQ SCORES... The cartoon shows an older brother choking his younger brother while banging on head of his younger brother. In obvious pain, the younger brother gasps, "I HAVE A THEORY..."
1. The following is from a 1922 article by Walter Lippmann who at that time was America's dean of political commentators. "The danger of the intelligence tests is that in a wholesale system of education, the less sophisticated or the more prejudiced will stop when they have classified and forget that their duty is to educate.... Readers who have not examined the literature of mental testing may wonder why there is reason to fear such an abuse of an invention that has many practical uses. The answer, I think, is that most of the more prominent testers have committed themselves to a dogma which must lead to just such abuse. They claim not only that they are really measuring intelligence, but that intelligence is innate, hereditary and predetermined. They believe that they are measuring the capacity of a human being for all time and that this capacity is fatally fixed by the child's heredity. Intelligence testing in the hands of men who hold this dogma could not but lead to an intellectual caste system in which the task of education had given way to the doctrine of predestination...If the intelligence test really measured the unchangeable hereditary capacity of human beings as so many assert, it would inevitably evolve from an administrative convenience into a basis for hereditary caste." In this age of continual testing, have Lippmann's fears come true? Or, are we more sophisticated in the 85 years since?
2. Returning to the Science article, it should be noted that none of the 240,000 Norwegians took an actual IQ test. The Norwegians took a different test, mean of 5, standard deviation of 2, and then a transform took place to deliver the customary mean of 100, standard deviation of 15. The authors justify this because the historical correlation between the test administered to the Norwegian conscripts and the WAIS IQ test has been .73. How good is a ".73" correlation coefficient?
3. Do a Google search to determine how many different IQ tests exist.
4. The Science article deals with Norwegian males. Comment on whether or not any inference can or should be made to males in other countries which are culturally less homogeneous and/or may have a different family structure.
5. On the basis of no data, speculate on what conclusions could be reached regarding female rank and IQ.