In 1905 psychologists Alfred Binet and Théodore Simon devised a psychological test to find out which children needed special attention in school. The pair later believed demonstrable skills such as verbal reasoning and working memory were indicative of intelligence… and created the basis of the IQ test.
“Simon and Binet thought that the skills assessed by their test reflected general intelligence. But both then and now, there is no single agreed-upon definition of general intelligence“, explains Dr. Stefan Dombrowski in a Ted-Ed Talk. At the time, however, IQ tests were misinterpreted, especially by eugenicists (i.e. those who believe in the concept of “race” and want to advance and develop only the one to which they belong by calling it “superior”) and military.
These intelligence tests were – at the time – used to determine who should be proposed for officer training, but in reality, US Army recruits came from diverse backgrounds and many were immigrants who they had no formal education or fluent Englishleading to negative scores, even if they were smarter.
Given the necessary premises, over time what scientists call the “Flynn Effect” has been observed. Put simply, i IQ points generally increase by about three points per decade. The effect can largely be explained by environmental factors, from improved schooling to better nutrition in the years following World War I and World War II.
However, a study conducted in Norway, where IQ tests have been analyzed for half a century, found shown a decline since the mid-1990s. Another Australian study of children showed no improvement in scores between 1975 and 2003, while tests in the UK showed showed a decline of about 2-6 points between 1980 and 2008. What is happening? Is humanity getting dumber?
Part of this reversal may be due to less emphasis placed on performing these testsas well as the changes in social class during this time period. It must also be considered that, before, students were educated precisely to “pass” these tests, while today it has no priority in our classrooms.
Meanwhile, the World Health Organization has proposed a possible explanation for the decline: a corresponding increase in pollution “which can damage the developing brain, which is of particular concern because this damage can impair cognitive function throughout the lifespan.“
Interestingly, in the 1980s, there was a drop in IQ of about four or five points due to lead pollution found inside gasoline for years. The good news is that – similar to the heavy metal – air pollution can be reduced, and with almost immediate health benefits.