3 ms·

I am going out of a limb and say that there is a chance that immigration is a factor as well. Pre 1990, the immigration in Europe was very limited, and after t

I am going out of a limb and say that there is a chance that immigration is a factor as well. Pre 1990, the immigration in Europe was very limited, and after the fall of Communism there have been large immigration movements within Europe, and now from outside it. Two main reasons immigrants could cause IQ changes: 1. Genetic variation (you are actually not measuring the same population in the 80s, and the 2000's). eg, Denmark's minority/immigrant population has changed a lot since the 80s, going from 3% to almost 12% today. That could be affecting the score. You are not measuring just Danes, but 88% Danes, 8% Turkish, and 4% others..... 2. Lots of immigrants came either for economic reasons, or actually from WAR (Yugoslav wars in the 90s). Early child trauma, lack of nutrition, and the difficulties of restarting life somewhere could affect IQ scores, as we know environment, especially in early childhood could affect the score If these measurements are coming from the Army, but they are not actually differentiating from first/second gen immigrants and original Danes, and then they are not really indicating that the local (original) population is having a decrease of IQ. Mostly than the newcomers have slightly lower IQs. Since Denmark was mentioned in the article, here is a chart of their immigrant population change over time, and it is pretty drastic. From a homogeneous population to a more diverse one: https://www.researchgate.net/profile/Emil_O_W_Kirkegaard/publication/273063136/figure/fig1/AS:294935698919426@1447329558387/Immigrant-population-size-over-time-in-Denmark.png https://www.researchgate.net/profile/Emil_O_W_Kirkegaard/pub...

bsaul 7y ago
Wondered about that as well, but another article, linked in the original one, mentions the original study dismisses that hypothesis, since it happens between members of the same family : https://www.sciencealert.com/iq-scores-falling-in-worrying-reversal-20th-century-intelligence-boom-flynn-effect-intelligence https://www.sciencealert.com/iq-scores-falling-in-worrying-r... "In the new study, the researchers observed IQ drops occurring within actual families, between brothers and sons – meaning the effect likely isn't due to shifting demographic factors as some have suggested, such as the dysgenic accumulation of disadvantageous genes across areas of society"
inscionent 7y ago
From the article: "However, a 2018 study of Norway has punctured these theories by showing that IQs are dropping not just across societies but within families. In other words, the issue is not that educated Norwegians are increasingly outnumbered by lower-IQ immigrants or the children of less-educated citizens. Even children born to high-IQ parents are slipping down the IQ ladder."
- ardit33 7y ago
  Interesting, thanks for the explanation
- iq-thrower1 7y ago
  One hypothesis which offers an explanation for this is the accumulation of deleterious mutations over generations, caused by a less harsh environment (e.g. medical care, technology) and advanced parental age, then accelerated by cultural changes [1]. [1] https://link.springer.com/article/10.1007/s40806-017-0084-x https://link.springer.com/article/10.1007/s40806-017-0084-x

bsaul 7y ago

Wondered about that as well, but another article, linked in the original one, mentions the original study dismisses that hypothesis, since it happens between members of the same family : https://www.sciencealert.com/iq-scores-falling-in-worrying-reversal-20th-century-intelligence-boom-flynn-effect-intelligence https://www.sciencealert.com/iq-scores-falling-in-worrying-r... "In the new study, the researchers observed IQ drops occurring within actual families, between brothers and sons – meaning the effect likely isn't due to shifting demographic factors as some have suggested, such as the dysgenic accumulation of disadvantageous genes across areas of society"

inscionent 7y ago

From the article: "However, a 2018 study of Norway has punctured these theories by showing that IQs are dropping not just across societies but within families. In other words, the issue is not that educated Norwegians are increasingly outnumbered by lower-IQ immigrants or the children of less-educated citizens. Even children born to high-IQ parents are slipping down the IQ ladder."

ardit33 7y ago
Interesting, thanks for the explanation
iq-thrower1 7y ago
One hypothesis which offers an explanation for this is the accumulation of deleterious mutations over generations, caused by a less harsh environment (e.g. medical care, technology) and advanced parental age, then accelerated by cultural changes [1]. [1] https://link.springer.com/article/10.1007/s40806-017-0084-x https://link.springer.com/article/10.1007/s40806-017-0084-x