IQ scores are falling, reversing a trend that saw scores rise at a steady rate through the 20th century, according to a new study.
Researchers from the Ragnar Frisch Center for Economic Research in Norway studied the IQ scores of about 730,000 Norwegian men born between 1962 and 1991. They found that scores increased by nearly three percentage points each decade for those born between 1962 and 1975. But among those born after 1975, the scores drop.
The cause of the drop in IQ is due to environmental factors, not genetics, said Ole Rogeburg, principal investigator at the Ragnar Frisch Center and co-author of the IQ score study, published in the journal Proceedings of the National Academy of Sciences. .
“It’s not that stupid people have more children than smart people, to put it bluntly,” Rogeburg told CNN. “It’s something to do with the environment, because we see the same differences within families.”
Environmental factors include differences in how young people are educated, increased time spent online, changes in nutrition and less reading in general.
The downward trend is a reversal of the Flynn Effect, a term that describes the vast improvement in IQ scores in many parts of the world throughout the 20th century. According to the study, the Flynn effect peaked in the mid-1970s and declined in the decades that followed.
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