Genealogy & General Subjects Blog



Monday, November 12, 2007

Smarter than Great-Grandma?

I recently came across this quotation in a book which really has little to do with genealogy otherwise:

"Further, we now know that culture exerts a more powerful effect than strictly biological factors in shaping our brains. Take, for example, the dramatic increase in the average IQ, which has climbed 24 points since 1918. Is this increase due to better education? Healthier diet? The greater amounts of information that our brains must now process compared to only a few years ago? Whichever explanation you favor (I favor the information link), the boost in IQ didn't simply come about simply by natural-selection-driven changes in the brain. The time frame is simply too short for such a degree of brain modification to be wrought by biological influences alone."
(From pp. 215-16 of The Naked Brain by Richard Restak. New York: Harmony Books, 2006.)
The immediate implication is that we are all smarter (on average) than our grandparents, at least by the measurement of the IQ tests. Given the standard deviations of IQ tests, this makes us significantly smarter on average than our great-grandparents. Restak cites a paper for Ronald Kotulak for his statistic. You can read Kotulak's explanation for why people might be getting smarter here.

However, it should be noted that IQ tests only measure certain kinds of intelligence. One test was invented in the early 1900s by Alfred Binet (though he may have disputed that it measured "intelligence") and various others have been introduced since then. Revisions have occured with all of them, naturally, although rigorous testing is usually done on all psychometric tests to see that scores from an older version of the same test or from different IQ tests translate to similar outcomes on the new tests. Still, these revisions and new tests may be imperfecly aligned with the originals.

Intriguingly, studies on the heritability of IQ have indicated fairly consistently that there is a genetic component to performance on the tests, particularly as one grows older. So even though we might be smarter than our great-grandparents, we still owe them a debt for making us smart.

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