IQ decreases

The Flynn Effect was the name given to the fact that several countries had reported findings which suggested that average IQ levels were increasing at a rate of 3 IQ points per decade in the United States. This finding would in fact suggest that Americans were getting smarter at a rate of 8-9 IQ points per generation. Scientists never reached consensus as to why this effect may have been taking place. Several explanations and theories were put worth including better diets and healthcare, the addition of iodine to salt, and the bombardment of information via technology. But although 3 IQ points per decade sounds large, this is eclipsed by some of the reported Flynn gains in other countries including the Netherlands, Belgium and Canada which experienced gains per decade of between 4-6 points according to some estimates. So for a while, it appeared that people were getting smarter, although this assertion was and is still debated. A new study has found the opposite and reports that IQs in the UK, Denmark and Australia have declined by 1.5 points since 1998, a finding that suggests the opposite of the Flynn Effect may be happening. Specifically, an IQ test used in Denmark to establish whether individuals are fit to serve in military has recorded a 1.5 point decline over a 16 year period. The IQ decreases have elicited a raft of responses by scientists. Although this could well be just a blip, these IQ decreases have caused a strong reaction in the scientific community, with some researchers suggesting that humans have reached an intellectual peak, and therefore that a gradual decline may have begun and that further IQ decreases may be yet to come. The relaxation of education standards may also be behind the trend.

IQ decreases: global vs national data

Richard Lynn from the University of Ulster has used average IQ data from several countries and has calculated that IQs have dropped by 1 point between 1950 and 2000.  If the answer really happens to be that average populations are 1 point dumber than they were 60 years ago, this is nothing to get alarmed about. This level of detail would be largely insignificant. One interesting explanation for these IQ decreases is that more educated people are having less children, which would mean that the less educated masses would be sustaining population numbers. This is not only entirely implausible but especially relevant when looking at the changes in IQ for the world as a whole given the very low birth rates in industrialized nations relative to developing economies. That said, developing countries are likely to experience some level of positive Flynn effect as they develop and begin offering their citizens better education, nutrition and healthcare. In fact, there is evidence that gains are more likely to accrue from a lower base than from a higher one. To test your IQ, go to and take our three fluid intelligence IQ tests.