It is not unusual for parents to comment that their children are brainier than they are. In doing so, they hide a boastful remark about their offspring behind a self-deprecating one about themselves. But a new study, published in the journal Intelligence, provides fresh evidence that in many cases this may actually be true. The researchers - Peera Wongupparaj, Veena Kumari and Robin Morris at Kings College London - did not themselves ask anyone to sit an IQ test, but they analysed data from 405 previous studies. Altogether, they harvested IQ test data from more than 200,000 participants, captured over 64 years and from 48 countries. Focusing on one part of the IQ test, the Raven's Progressive Matrices, they found that on average intelligence has risen the equivalent of 20 IQ points since 1950. IQ tests are designed to ensure that the average result is always 100, so this is a significant jump. The gains have not been evenly spread. IQ has generally increased more rapidly in developing countries, with the biggest leaps seen in China and India. Progress in the developed world has been chequered - the data seem to indicate steady increases in the US, for example, but a decline in the UK. The new research is further confirmation of a trend that scientists have been aware of for some time. In 1982, James Flynn, a philosopher and psychologist based at the University of Otago in New Zealand, was looking through old American test manuals for IQ tests. He noticed that when tests were revised every 25 years or so, the test-setters would get a panel to sit both the old test and the new one. "And I noticed in all the test manuals, in every instance, those who took the old test got a higher score than they did on the new test," says Flynn. In other words, the tests were becoming harder. This became known as the Flynn Effect, though Flynn stresses he was not the first to notice the pattern, and did not come up with the name. But if the tests were getting harder, and the average score was steady at 100, people must have been getting better at them. It would seem they were getting more intelligent. If Americans today took the tests from a century ago, Flynn says, they would have an extraordinarily high average IQ of 130. And if the Americans of 100 years ago took today's tests, they would have an average IQ of 70 - the recognized cut-off for people with intellectual disabilities. To put it another way, IQ has been rising at roughly three points per decade. This is a puzzle not just for the US, but for all countries demonstrating the Flynn Effect. "Does it make sense," Flynn wrote in one paper, "to assume that at one time almost 40% of Dutch men lacked the capacity to understand soccer, their most favoured national sport?" So what is going on? "There are lots of theories, none of which is particularly proven," says Robin Morris.
One possible explanation has to do with changes in education.
In most of the developed world, more people are now in school for longer, and teaching methods have evolved, moving away from the simple memorising of names, dates and facts. It seems like a reasonable assumption that education is training people to think better.
But in fact, the evidence is mixed. There has been no clear correlation between the rising IQ scores and US school performance - in SAT tests, for example.
But school prepares children for sitting IQ tests in other ways - what the psychologist Arthur Jensen has called "test wiseness". Over time, students become used to the pressure of tests and they pick up examination-room tactics that improve their performance. The full article can be found here:-
Further information –follow up at James Flynn’s Ted Talk where he challenges our fundamental assumptions about intelligence.