Our Shrinking IQ: New Icelandic Study Shows 0.04 Point Drop In IQ Per Decade

A new study in Iceland is one of the latest to show that natural selection may be slowly eradicating our education genes and reducing our IQ scores each decade. The newest research on this phenomenon was conducted by deCODE, a genetics firm located in Reykjavik. They have discovered that groups of genes which would normally "predispose" people to spend many years involved in higher education have gone down in Iceland over the years 1910 to 1975.

In order to study the phenomenon of the shrinking IQ, scientists looked at a database of 100,000 people in Iceland to try to learn how different gene variants could affect education over time and found a small decline over 65 years. But scientists also discovered that these same genes not only affected education, they also affected fertility, as The Guardian report.

The fertility issue was noticed as the Icelandic people who were found to carry more of the education genes had less children than others. Scientists decided that perhaps this was because those with education genes tended to have smaller families, thus contributing less to the gene pool than others in Iceland. However, this study showed that spending longer years studying wasn't the cause of those with education genes having fewer children as many of those who had these education genes left school early and still had fewer children than the general Icelandic population.

Students graduating from Harvard University on June 4, 2009.
Students graduating from Harvard University on June 4, 2009. New research in Iceland shows a possible decline in our IQs over the coming decades. [Image by Darren McCollester/Getty Images]

Kari Stefansson, who led the study on the declining IQ, explained that education wasn't the cause of people with education genes have less children.

"It isn't the case that education, or the career opportunities it provides, prevents you from having more children. If you are genetically predisposed to have a lot of education, you are also predisposed to have fewer children."
This new research shows that while there is a statistical drop in our IQs, that effect is still small. Researchers writing in the Proceedings of the National Academy of Sciences have said that the drop in IQ is 0.04 points each decade. However, Kari Stefansson does feel that if this trend were to continue over the coming centuries that there is the potential of a much greater impact.
"The cumulative effect over time means this is going to have a dramatic effect on the genetic predisposition to educational attainment, and unless something comes along to counteract that, it could have a profound effect on educational attainment in our society."
Other scientists point out that genes only have a small influence on our education. Melina Mills, a professor of Sociology at the University of Oxford, explained that despite studies showing drops in our IQ, these effects are really quite small.
"There are a number of studies saying we are getting dumb and dumber, but the effects are really weak. The education we have, when we have children and how many, is largely socially and environmentally determined. It overrides the genetic effect. Over the years, we've had an expansion in education and women can now have three to four more years of education than they did in 1910. There is definitely a genetic overlap between higher educational attainment, having children later and having fewer children. But whether you can say that results in changes over time, and in evolution, I'm not so sure."
In 2016, Harvard economist Jonathan Beauchamp stated that natural selection was in place and acting against genetic variants when it came to education in the American population. However, he also said that if you wanted to predict future trends with this that it would be extremely difficult as nobody knows what kind of changes there will be in society over the coming decades or centuries.

Kari Stefansson does concede that if there are any changes within the population, it will "swamp" any genetic effects. Kari noted that IQ points actually jumped 14 points between the years 1932 and 1978 as there were such large socioeconomic changes within the population. Stefansson noted that there were many changes in the environment that could stop the decline of IQs.

Cambridge Univeristy students punt along the River Cam on April 19, 2011.
Cambridge University students punt along the River Cam on April 19, 2011. [Image by Oli Scarff/Getty Images]

Behavioral Geneticist at Kings College London, Richard Plomin, explained that this latest study in shrinking IQs was a demonstration showing how polygenic scores, which are the things that measure an individual's strengths and weaknesses in a genetic sense, are part of the DNA revolution.

"They have already changed science and will soon affect the clinic and society."
What do you think of this latest Icelandic study on the small decline in IQs and how do you think it might change over the coming decades or centuries?

[Featured Image by Carl Court/Getty Images]