IQ scores of young people are dropping by seven points every generation, research shows
The decline in IQ is thought to have begun with those born in 1975 and became adults in the early 1990s
A new study has found that young people's IQ scores have once again started to deteriorate after climbing steadily since the World War II.
According to the first authoritative study of the phenomenon, the fall is believed to have started with those born in the year 1975 and equates to about seven points per generation.
The trend apparently marks the end of the "Flynn effect", which saw average IQ scores rise by roughly three points a decade for the past 60 to 70 years, reports The Sun.
According to the Times, scientists are describing the drop in scores as "impressive" but "pretty worrying".
Scientists are attributing the decline to a difference in technique in the way maths and languages are taught in schools.
But it could also be due to people spending more time on mobile devices and less time reading books, some others suggested.
Stuart Ritchie, a psychologist at the University of Edinburgh, did not participate in the research, but told the newspaper: "This is the most convincing evidence yet of a reversal of the Flynn Effect. If you assume their model is correct, the results are impressive, and pretty worrying."
That being said, according to previous studies, IQ scores might have fallen since the turn of the new millennium. The drop has been calculated to be between 2.5 and 4.3 points every ten years, according to two British studies.
However, the results were not widely accepted due to the limited nature of the research.
Also, it was found that Norwegian men's IQ had dropped compared to the scores their fathers got when they were of the same age, according to the latest study conducted by Ole Rogeburg and Bernt Bratsberg of the Ragnar Frisch Centre for Economic Research in Oslo.
Their evaluation was performed on the scores obtained from a standard IQ test of over 730,000 men who reported for national service between the years 1970 and 2009. The aforementioned research has already been published in the Proceedings of the National Academy of Sciences of the United States of America Journal (PNAS).
Scientists had revealed in December 2017 that regularly consuming fish improves children's intelligence and helps them sleep better. The study also found that 11-year-olds scored almost 5 points higher in IQ tests if they consume fish frequently as compared to those who "seldom" do.
More than 500 children were asked in the study conducted by US researchers about how often they ate fish in the past month. The options ranged from "never", right up to "at least once per week".
Following the multiple-choice question, the same group participated in an IQ test which constituted verbal and written communication skills.
It was found that children who eat fish at least once a week score 4.8 points higher than those who never do. The study also took into consideration factors such as occupation, marital status, and parental education.
Fascinatingly, even those subjects who sometimes included fish in their meals scored 3.3 points higher than others who didn't.
Back in August 2014, Professor James Flynn of the University of Otago, after whom the "Flynn effect" is named, said that the increase in intelligence in the Western world post World War II could be attributed to improved living conditions, better nutrition, as well as better education.
The results could also be the result of less intelligent youth culture, according to Professor Flynn.
At the time, Flynn found that children aged between five and 10 saw their IQs increase by half a point every year over three decades, using data gathered in IQ tests on UK children.
"Other studies have shown how pervasive teenage youth culture is, and what we see is parents' influence on IQ slowly diminishing with age," he said. "What we know is that youth culture is now more visually orientated around computer games than they are in terms of reading and holding conversations."