Dumb and dumber: why we’re getting less intelligent

Dumb and dumber: why we’re getting less intelligent, by Oliver Moody.

The IQ scores of young people have begun to fall after rising steadily since the Second World War, according to the first authoritative study of the phenomenon.

The decline, which is equivalent to at least seven points per generation, is thought to have started with the cohort born in 1975, who reached adulthood in the early Nineties. …

The turning point marks the end of a well-known but poorly understood trend known as the Flynn effect, in which average IQs have risen by about three points a decade for the past 60 or 70 years.

“This is the most convincing evidence yet of a reversal of the Flynn effect,” Stuart Ritchie, a psychologist at the University of Edinburgh who was not involved in the research, said. “If you assume their model is correct, the results are impressive, and pretty worrying.”

There had been signs that IQ scores might have fallen since the turn of the millennium. Two British studies suggested that the decline was between 2.5 and 4.3 points per decade. This has not been widely accepted owing to the limited research to date. A study has now shown, however, that Norwegian men’s IQs are measurably lower today than the scores of their fathers at the same age. …

The reasons behind the Flynn effect and its apparent reversal are disputed. Scientists have put the rise in IQ down to better teaching, nutrition, healthcare and even artificial lighting.

Some academics suggest the recent fall could be down to genetics. Their argument is, crudely, that less intelligent people have more babies, and so over time the gains are cancelled out by the spread of genes linked to low-intelligence.

Yet this theory has been scotched by the Norwegian paper. Because the decline can be observed within the same families, it is unlikely to be the result of a demographic shift.

Well that would be politically incorrect, and this is a PC article. Logic and PC are not renowned for hanging out together. Seriously though, the Norwegian study appears to rule out this component in the IQ drop — i.e. the reported IQ drop is not because of smarter people breeding less, which may be occurring in addition to the effect measured here.

Dr Rogeberg said it was more plausible that the changes in the way children are educated or brought up -– such as less time drilling pupils in reading and mathematics -– were at play.

He stressed that the findings did not necessarily mean that today’s young people were any more stupid than their parents. Instead, it may be that definitions of intelligence have yet to catch up with the skillset needed to navigate the digital era.

“Intelligence researchers make a distinction between fluid and crystallised intelligence,” he said. “Crystallised intelligence is stuff you have been taught and trained in, and fluid intelligence is your ability to see new patterns and use logic to solve novel problems.”

Classic IQ tests, with their emphasis on arithmetic and verbal reasoning, tend to favour the kind of crystallised intelligence that is fostered by a more traditional education. “If this is the underlying cause of the decline, this need not be overly worrying,” Dr Rogeberg said.

The other genetic reason for a declining IQ is the absence of natural selection. Until the industrial revolution all populations in the world lived on the Malthusian edge, on the limit and unable to expand much. Now that hunger and many diseases have been conquered,  individuals with more defects are breeding as fast as those with fewer, so genetic defects are presumably building up.