The Flynn effect is the substantial and long-sustained increase in both fluid and crystallized intelligence test scores that were measured in many parts of the world over the 20th century. When intelligence quotient (IQ) tests are initially standardized using a sample of test-takers, by convention the average of the test results is set to 100 and their standard deviation is set to 15 or 16 IQ points. When IQ tests are revised, they are again standardized using a new sample of test-takers, usually born more recently than the first. Again, the average result is set to 100. However, when the new test subjects take the older tests, in almost every case their average scores are significantly above 100.
Test score increases have been continuous and approximately linear from the earliest years of testing to the present. For the Raven's Progressive Matrices test, a study published in the year 2009 found that British children's average scores rose by 14 IQ points from 1942 to 2008. Similar gains have been observed in many other countries in which IQ testing has long been widely used, including other Western European countries, Japan, and South Korea.This effect is strong evidence against intelligence being overwhelmingly heritable (though since IQs run from less than 50 to 200+, there's still a fair amount of potential room for nature). As a result, James R. Flynn (for whom the Effect was named), has been somewhat of a hero for those who discount the heritable nature of intelligence.
It seems, though, that Mr. Flynn's hero status has waned substantially. He recently tried to get a book published (In Defense of Free Speech: The University as Censor), but it was rejected out-of-hand by the publisher. The reasons for the rejection were explained in an email (the whole article is interesting) from the publisher:
I am contacting you in regard to your manuscript In Defense of Free Speech: The University as Censor. Emerald believes that its publication, in particular in the United Kingdom, would raise serious concerns. By the nature of its subject matter, the work addresses sensitive topics of race, religion, and gender. The challenging manner in which you handle these topics as author, particularly at the beginning of the work, whilst no doubt editorially powerful, increase the sensitivity and the risk of reaction and legal challenge. As a result, we have taken external legal advice on the contents of the manuscript and summarize our concerns below.
There are two main causes of concern for Emerald. Firstly, the work could be seen to incite racial hatred and stir up religious hatred under United Kingdom law. Clearly you have no intention of promoting racism but intent can be irrelevant. For example, one test is merely whether it is “likely” that racial hatred could be stirred up as a result of the work. This is a particular difficulty given modern means of digital media expression. The potential for circulation of the more controversial passages of the manuscript online, without the wider intellectual context of the work as a whole and to a very broad audience—in a manner beyond our control—represents a material legal risk for Emerald. ... [emphasis added]The ironies are frightening (to me), yet delicious. The first is that a book arguing for free speech is censored. That's kinda gettin' near the end of the road for free speech, isn't it? The second is that a progressive hero is censored. As long as he was willing to research and write stuff that supports that which all right thinking people are certain is correct, he's a hero and is cited incessantly. Write something a little different and bzzzzt, throw the bastard out.
The truth may be dangerous and now we're at a point where trying to find the truth is even more dangerous.