Intelligence Decline in the average intelligence of the population in advanced industrial nations

@Dagne,
I think you are still missing the point :)

Humans have not just 1 chromosome (the XX or XY one) but 23 of them - one sex based (XX, XY) and 22 autosomal. And genes responsible for IQ are not exclusively located in sex based allosome, but also are present in some or all of 22 others. The ones from X are indeed not passed from father to son, but all the other 22 are a combination from both parents.

Apparently Y chromosome does not pass IQ related traits or it is not found out yet.

But you see, the point is that IQ gene variants that are received from father are conditioned
"scientists now believe genes for advanced cognitive functions which are inherited from the father may be automatically deactivated"

this is a new finding that we are talking about.
 
some studies suggest that intelligence is inherited from the mother. These findings were initially found in studies on mice, but confirmed when extrapolated to human brains. This was carried out by a study conducting a survey on >12,000 people. Paternal genes tend to accumulate in the limbic system, which is concerned with aggression, hunger, e.t.c. basic instincts. No paternal gene is found in the cerebral cortex, which is concerned with advanced functions like learning, reading, e.t.c. Intelligence genes are carried by the X chromosome, which are 2 with women. Even if it comes from the X chromosome of the father, it gets deactivated."
https://www.newtimes.co.rw/section/read/228963
Sorry, Dagne, but it doesn't seem new. That must be 1996. The article I posted from Forbes explained it (it's not about environment only, and the first I posted not even mention X chromosome).

"What they’re really describing (I think) is the results of a 1996 paper that reports using mouse embryos that were a mix of cells, some carrying double paternal genomes and some carrying double maternal genomes. Some parts of the mouse brain that developed carried far more of one than the other whereas other parts of the brain showed a reverse pattern. The senior author on that paper, Cambridge University neuroscientist Barry E. Keverne, himself wrote in 2013 that some of the findings may have been the result of a 'failure of these (double paternal) cells to thrive and survive when they reach the developing cortex.'"

And the article continues... I won't quote it all here, but anyone interested on the matter should read it all.

Point is, in short, that intelligence is a very complex phenotype, and saying "intelligence comes from mother" (or X), this way, seems an exaggeration, apparently not really supported by science so far.

@Farstar
Interesting point.
 
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I find it really sad is that humanity will have less and less IQ because clever women are less reproductive. It is likely that men can inherit their IQ only from their mothers...




Reminds me of the intro of the film, idiocracy. Where the intelligent refuse to have kids until they are more financially secure.

 
But you see, the point is that IQ gene variants that are received from father are conditioned
"scientists now believe genes for advanced cognitive functions which are inherited from the father may be automatically deactivated"

this is a new finding that we are talking about.
Full quote I guess is this:
“Even if it comes from the X chromosome of the father, it gets deactivated."
From X chromosome..

What I am saying is - cognitive functions do not come exclusively from sex based chromosome which is just 1 of 23 chromosomes..

Do you think autosomes do not contain genes enhancing/impacting cognitive functions?
 
George Bernard Shaw may have anticipated this debate. A beautiful young society woman approached him at a party and said "George, with your intelligence and my looks, imagine the wonderful children we could have together." He replied "But, my dear, what if they have my looks and your intelligence?"
 
Would be interesting to research if these feminist lesbians and single mothers who go to sperm banks and choose very high IQ genius men as donors, give birth to genius kids. If they don't then probably Dagne is right.
 
Want to know the possible IQ of a child? Take the father's and mother's, add and divide by 2. :)

There was a Nobel Scientist who started a sperm bank with donors who were also Nobel scientists or otherwise could show they had a high IQ.

To be accepted as a "donee", a woman had to have a certain minimum IQ. If my memory serves, it was pretty high, above 120.

He clearly knew that the mother's IQ matters as well.
 
Want to know the possible IQ of a child? Take the father's and mother's, add and divide by 2. :)

There was a Nobel Scientist who started a sperm bank with donors who were also Nobel scientists or otherwise could show they had a high IQ.

To be accepted as a "donee", a woman had to have a certain minimum IQ. If my memory serves, it was pretty high, above 120.

He clearly knew that the mother's IQ matters as well.

Angela, taking the average IQ of the parents is known to be (by research) the best IQ estimate for their children? It seems logical, but I have never been able to find literature stating this fact. Very often, researchers speak about the correlation in IQ (between children and parents), but they do not explain how this correlation is calculated.
 
Angela, taking the average IQ of the parents is known to be (by research) the best IQ estimate for their children? It seems logical, but I have never been able to find literature stating this fact. Very often, researchers speak about the correlation in IQ (between children and parents), but they do not explain how this correlation is calculated.

It's not quite as simple as that, i.e. a strict average. :) I was being a bit flip. It will, however, be somewhere in that range. It's just so obvious that I can't understand the resistance to the idea that it's heritable and that one has to consider the IQ of both parents, especially in light of all the data that's been generated for decades.

There are many components to an IQ score. When you get recombination in the sex cells, there isn't a strict division.

I'm sure people are sick about hearing about my brother and me, but we're really a very good illustration of this. We're sort of mirror opposites of each other. On the SAT scores I got an 800 on the verbal and 720 on the math. He got 800 on the math and 720 on the verbal. Total IQ scores are in the same ballpark, but not exactly the same. He got more of certain skills and I got more of others. I think he is better functioning on the visual/spatial side of the equation because he got those alleles both from my mother's side (her father and a cousin were/are both engineers, the latter working on managing the water problem in Venice), and my father, wonderful at math, and very visually oriented (his dream had been to be an architect). I don't think I got those same alleles from my mother as my brother got. I got the verbal aptitude ones from her instead, with a brother and cousin who were writers and journalists, and from my father as well, along with some of his math skills. My brother's IQ is not only slightly higher than mine, but I think it's probably a bit higher than my father's and mother's as well. It's serendipity depending upon which specific alleles are inherited and how they influence one another.

Also, after awhile there's what they call regression toward the mean. For example, the children of two people with a genius level IQ will still have a high IQ, but perhaps not as high as the parents. It applies to things like musical ability too. The Bach family is an example. Generations of talented musicians, before and after him, but only one Johann Sebastian Bach, unfortunately. :)

You can also have rare cases where parents with high average IQ can produce a prodigy. Again, serendipity. Just the right combination of alleles from both lines, plus, perhaps, some de novo mutations.

Those are the subtleties.

The general takeaway is the same, however. The IQ of both parents is important, and the IQ of the child will more than likely be in the same ballpark as the parents sort of averaged. In most cases there isn't a big disparity in the IQ of the father versus the mother anyway, of course, because in this day and age assortative mating is particularly strong in the area of intellectual functioning. That wasn't always the case. Many marriages in the past, as I'm sure you know, were based on land and property, or an older man on his second or third wife just marrying someone on the basis of looks.

Fwiw, I looked up that sperm bank, and the Wiki article says that the media reports about the qualifications of the women "donees" were incorrect.

See:
https://en.wikipedia.org/wiki/Repository_for_Germinal_Choice
 
Individuals are getting more moronic. That is not a judgment; it's a worldwide actuality. In a large group of driving countries, IQ scores have begun to decrease.


Despite the fact that there are real issues about the connection among IQ and insight, and wide acknowledgment that achievement depends as much on different excellencies like coarseness, IQ tests being used all through the present reality truly appear to catch something important and tough. Many years of exploration have demonstrated that singular IQ scores foresee things, for example, instructive accomplishment and life span. All the more comprehensively, the normal IQ score of a nation is connected to monetary development and logical advancement.


So if IQ scores are truly dropping, that couldn't just mean 15 additional periods of the Kardashians, yet additionally the possible finish of progress on all these different fronts, at last prompting less logical achievements, stale economies and a general darkening of our aggregate future.
 
Individuals are getting more moronic. That is not a judgment; it's a worldwide actuality. In a large group of driving countries, IQ scores have begun to decrease.

I'm not sure what a driving country is, but can you cite published research that supports your claim?

Previous research has shown that average IQ increased in many countries during the 20th century. This is called the Flynn effect. James Flynn is the IQ researcher who showed this. Because of the Flynn effect, IQ tests had to be re-calibrated to keep the average at 100.

If this trend has reversed recently, IQ scores will have to decrease markedly to be back to what they were 100 years ago, so perhaps there is no reason for pessimism yet.
 

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