This was written by cognitive scientist Daniel Willingham, a psychology professor at the University of Virginia and author of “Why Don’t Students Like School?” His next book, “When Can You Trust The Experts? How to tell good science from bad in education,” will be published in July. This appeared on his Science and Education blog.

By Daniel Willingham

You may remember “The Bell Curve.” The book was published in 1994 by Richard Herrnstein and Charles Murray, and it argued that IQ is largely determined by genetics and little by the environment. It further argued that racial differences in IQ tests scores were likely due to genetic differences among the races.

A media firestorm ensued, with most of the commentary issuing from people without the statistical and methodological background to address the core claims of the book.

The American Psychological Association created a panel of eminent researchers to write a summary of what was known about intelligence, which would presumably contradict many of these claims. The panel published the article in 1996, a thoughtful rebuttal of many of the inaccurate claims in “The Bell Curve,” but also a very useful summary of what some of the best researchers in the field could agree on when it came to intelligence.

Now there’s an update.

A group of eminent scientists thought the time was ripe to provide the field with another status-of-the-field statement. They argue that there have been three big changes in the 15 years since the last report:

(1) we know much more about the biology underlying intelligence; (2) we have a much better understanding of the impact of the environment on intelligence, and that impact is larger than was suspected; (3) we have a better understanding of how genes and the environment interact.

Some of the broad conclusions are listed below (note that these are close paraphrases of the article’s abstract).

The extent to which genes matter to intelligence varies by social class (genetic inheritance matters more if you’re wealthy, less if you’re poor).

Almost no genetic polymorphisms have been discovered that are consistently associated with variation of IQ in the normal range.

“Crystallized” and “fluid” intelligence are different, both behaviorally and biologically.

The importance of the environment for IQ is established by the 12 to 18 point increase in IQ observed when children are adopted from working-class to middle-class homes.

In most developed countries studied, gains on IQ tests have continued, and they are beginning in the developing world

Sex differences in some aspects of intelligence are due partly to biological factors and partly to socialization factors.

The IQ gap between blacks and whites in the United States has been reduced by 0.33 standard deviations in recent years.

The article is well worth reading in it’s entirety. Download it here.


Other Willingham pieces you may like:

Left/right brain theory is bunk

3 brain facts every educator should know

Does chaos at home lower a child’s IQ?

Willingham archive on The Answer Sheet

And this piece Q & A I did with a psychologist about whether geniuses are born or made.


Sources Willingham cites for his post:

Neisser, U.; Boodoo, G.; Bouchard, T. J. , J.; Boykin, A. W.; Brody, N.; Ceci, S. J.; Halpern, D. F.; Loehlin, J. C. et al (1996). Intelligence: Knowns and Unknowns. American Psychologist, 51: 77.

Nisbett, R. E., Aronson, J., Blair, C., Dickens, W., Flynn, J., Halpern, D. F., & Turkheimer, E. (2012, January 2). Intelligence: New Findings and Theoretical Developments. American Psychologist, 67, 130-159.


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