THE PSYCHOLOGIST : Scientists find the human brain has grown by whopping 7% since 1930... but there are signs IQs have gone backwards in recent years

Scientists find the human brain has grown by whopping 7% since 1930... but there are signs IQs have gone backwards in recent years

This is an interesting paradox. There is a long-standing correlation of about 0.3 between brain size and IQ. So the findings are weakly contradictory. I think, however, that I may be able to give an outline of a solution to that puzzle.

I once hypthesized that better perinatal practices were reponsible for the average IQ gains that were observed in many countries during the 20th century

http://jonjayray.com/iqgain.html

If my hypothesis is correct, the benefit of improved obstetric practice should level out once best delivery procedures became normal. And it was so. The growth in IQ scores did level out towards the end of the 20th century.

But we need to ask the old legal question "cui bono?". Which babies did it help most? Babies who were physically normal would be helped to survive with undamaged brains so brain damage due to delivery practices should be rare and hence lead to a rise in average IQ.

And the correlation between higher IQ and larger brains means that less pressure on the head during delivery (due to episiotomy, Caesarians, principally) would be particulary helpful to undamaged survival among individuals with big heads. So a major source of better and undamaged survival among high IQ individuals would be the safer delivery of big headed babies

But what about babies which had some congenital problem that only modern medicine saved from oblivion? In many cases the congenital problem would have affected the brain and Left us with an individual of lower IQ, much lower in some cases

So we have two populations with opposite effects from modernity. "Normals" who avoided damage so became brighter on average and another which survived against the odds and which was on the average of lower IQ. So what we find reported below is the averaging out of those two populations

A note of caution, however. It is much easier and more accurate to measure head size than it is to measure IQ, and the IQ gain reported is quite low and of no certain reliabiity. And in general the higher you go up the IQ scale the lower is the reliability of the differences. So much more segmentaion of the populations concerned would be needed to give any certainty about what is going on

Gen Z and Alpha may have a larger brain than people who were born 100 years ago, yet studies have indicated they also have the lowest IQs of previous generations.

Researchers at the University of California (UC) Davis Health studied different brain sizes of people born from the 1930 through 1970s, finding a 6.6 percent increased in brains among Gen X compared to the Silent Generation.

The team theorized that growth could be caused by external influences like health, social, cultural and educational outside factors and could reduce the risk of age-related dementia.

It comes as more recent studies have indicated that even younger generations' IQ scores have dropped in recent decades, which researchers have linked to an overreliance on phones and the internet.

Brain size doesn't necessarily make people more intelligent, and research has suggested that their is only a slight relationship between the two.

Neuroscientists have found that extra brain mass actually accomplishes very little when it comes to intelligence, and instead it serves to allow people to store more lifetime memories, according to Psychology Today.

However, the latest findings could be a contributing factor to why younger generations have a lower risk for developing dementia or Alzheimer's.

The new study was conducted across 75 years and found the brain consistently grew by 6.6 percent for people in the 1970s compared to those born in the 1930s.

Today's generation's brains measure about 1,400 milliliters in volume, but the average brain volume for people born in the 1930s was 1,234 milliliters.

The researchers reported that factors like greater educational achievements and better management of medical issues might explain why people's brains have grown over the decades.

'The decade someone is born appears to impact brain size and potentially long-term brain health,' said Charles DeCarli, first author of the study and professor of neurology at the UC Davis Alzheimer's Disease Research Center.

Researchers looked at patterns of cardiovascular and other diseases of people born in the 1930s and introduced MRI tests (brain magnetic resonance imaging) of people of the second and third generations of the original 5,200 participants.

The MRIs were conducted between 1999 and 2019 on people born in the 1930s through the 1970s, consisting of more than 3,000 participants with an average age of 57 years old.

The area of the brain that grew the largest was the cortical surface area which controls motor activities and sensory information.

Scientists have uncovered hundreds of different and unique regions of the brain

They reported that the area increased by 15 percent in volume and the region of the brain involved in learning and memory, called the hippocampus, had also increased in size.

However, the number of people struck by Alzheimer's has decreased by 20 percent since the 1970s, according to a separate study, and researchers are now saying increased brain size may be the culprit.

'Larger brain structures like those observed in our study may reflect improved brain development and improved brain health,' DeCarli said.

'A larger brain structure represents a larger brain reserve and may buffer the late-life effects of age-related brain diseases like Alzheimer's and related dementias.'

The brain growth in younger generations could increase brain connectivity, the study said, which could lead to more accurate and efficient performances on tasks.

Yet, even as researchers report the brain is growing with each generation, Gen Z and Alpha's IQs have dropped by at least two points, according to studies in Finland, France, the UK and other countries.

A 2023 study reported that IQ scores in the US have also dropped, but did not specify the exact drop, adding that the decrease could be due to disruptions to in-person learning during the Covid-19 pandemic.

The researchers also said the rise in social media use could be at fault, as skills like verbal reasoning, visual problem solving and numerical series tests have all gone down.

Academic and science presenter professor Jim Al-Khalili previously told Dailymail.com in 2022 that despite our ‘vastly increased scientific knowledge… the human brain hasn’t got bigger or more efficient or better than it was thousands of years ago.'

This is in direct contrast to the newest findings that the human brain is getting larger, but also raises the question of how cognitive development is increasing while gen Z and Alpha struggle to meet the same IQ levels as past generations.

https://www.dailymail.co.uk/sciencetech/article-13244559/Gen-Z-Alpha-larger-brains-IQs-decreasing.html

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Background

The essence of conservatism is caution. The essence of Leftism is anger

This blog is written solely by John Ray, who has a Ph.D. degree in psychology and 200+ papers published in the academic journals of the social sciences. It does occasionally comment on issues in psychology but is mainly aimed at giving a conservative psychologist's view on a broad range of topics. There are very few conservative psychologists.

The blog originated in Australia and many (but not most) posts discuss Australian matters. Australians have an unusually good awareness of events outside their own country. Australian newspapers feature news from Britain and the USA not as an afterthought but as a major part of their coverage. So Australians do tend to have a truly Western heart, which is the reason behind the old name for this blog. So events in Australia, Britain and the USA all feature frequently here, plus occasional coverage of other places, particularly Israel.

A primer in American politics for non-Americans:

SCOTUS is the Supreme Court of the United States, the highest court in the land

The "GOP" stands for "Grand Old Party" and refers to the Republican party. The GOP is at present center/Right, while the Democrats have been undergoing a steady drift Leftwards and now have policies similar to mainstream European Leftist parties.

The ideological identity of both parties has however been very fluid -- almost reversing itself over time. In the mid 19th century, the GOP was the party of big government and concern for minorities while the Democrats advertised themselves as "The party of the white man" -- an orientation that lasted into the mid 20th century in the South. The Democrats are still obsessed with race but have now flipped into support for discrimination AGAINST whites.

Was Pope Urban VIII the first Warmist? Below we see him refusing to look through Galileo's telescope. People tend to refuse to consider evidence— if what they might discover contradicts what they believe.

Global warming

Calibrated in whole degrees. Larger graph here

Climate scientist Lennart Bengtsson said. “The warming we have had the last 100 years is so small that if we didn’t have meteorologists and climatologists to measure it we wouldn’t have noticed it at all.”

The term "Fascism" is mostly used by the Left as a brainless term of abuse. But when they do make a serious attempt to define it, they produce very complex and elaborate definitions -- e.g. here and here. In fact, Fascism is simply extreme socialism plus nationalism. But great gyrations are needed to avoid mentioning the first part of that recipe, of course.

Two examples of Leftist racism below (much more here and here):

Beatrice Webb, a founder of the London School of Economics and the Fabian Society, and married to a Labour MP, mused in 1922 on whether when English children were "dying from lack of milk", one should extend "the charitable impulse" to Russian and Chinese children who, if saved this year, might anyway die next. Besides, she continued, there was "the larger question of whether those races are desirable inhabitants" and "obviously" one wouldn't "spend one's available income" on "a Central African negro".

Hugh Dalton, offered the Colonial Office during Attlee's 1945-51 Labour government, turned it down because "I had a horrid vision of pullulating, poverty stricken, diseased nigger communities, for whom one can do nothing in the short run and who, the more one tries to help them, are querulous and ungrateful."

Defensible and indefensible usages of the term "racism"

The book, The authoritarian personality, authored by T.W. Adorno et al. in 1950, has been massively popular among psychologists. It claims that a set of ideas that were popular in the "Progressive"-dominated America of the prewar era were "authoritarian". Leftist regimes always are authoritarian so that claim was not a big problem. What was quite amazing however is that Adorno et al. identified such ideas as "conservative". They were in fact simply popular ideas of the day but ones that had been most heavily promoted by the Left right up until the then-recent WWII. See here for details of prewar "Progressive" thinking.

R.I.P. Augusto Pinochet. Pinochet deposed a law-defying Marxist President at the express and desperate invitation of the Chilean parliament. He pioneered the free-market reforms which Reagan and Thatcher later unleashed to world-changing effect. That he used far-Leftist methods to suppress far-Leftist violence is reasonable if not ideal. The Leftist view that they should have a monopoly of violence and that others should follow the law is a total absurdity which shows only that their hate overcomes their reason

Franklin Delano Roosevelt was a war criminal. Both British and American codebreakers had cracked the Japanese naval code so FDR knew what was coming at Pearl Harbor. But for his own political reasons he warned no-one there. So responsibility for the civilian and military deaths at Pearl Harbor lies with FDR as well as with the Japanese. The huge firepower available at Pearl Harbor, both aboard ship and on land, could have largely neutered the attack. Can you imagine 8 battleships and various lesser craft firing all their AA batteries as the Japanese came in? The Japanese naval airforce would have been annihilated and the war would have been over before it began.

FDR prolonged the Depression. He certainly didn't cure it.

WWII did NOT end the Great Depression. It just concealed it. It in fact made living standards worse

Joe McCarthy was eventually proved right after the fall of the Soviet Union. To accuse anyone of McCarthyism is to accuse them of accuracy!

The KKK was intimately associated with the Democratic party. They ATTACKED Republicans!

People who mention differences in black vs. white IQ are these days almost universally howled down and subjected to the most extreme abuse. I am a psychometrician, however, so I feel obliged to defend the scientific truth of the matter:

The average African adult has about the same IQ as an average white 11-year-old and African Americans (who are partly white in ancestry) average out at a mental age of 14. The American Psychological Association is generally Left-leaning but it is the world's most prestigious body of academic psychologists. And even they have had to concede that sort of gap (one SD) in black vs. white average IQ. 11-year olds can do a lot of things but they also have their limits and there are times when such limits need to be allowed for.

America's uncivil war was caused by trade protectionism. The slavery issue was just camouflage, as Abraham Lincoln himself admitted. See also here

Did William Zantzinger kill poor Hattie Carroll?

Did Bismarck predict where WWI would start or was it just a "free" translation by Churchill?

Leftist psychologists have an amusingly simplistic conception of military organizations and military men. They seem to base it on occasions they have seen troops marching together on parade rather than any real knowledge of military men and the military life. They think that military men are "rigid" -- automatons who are unable to adjust to new challenges or think for themselves. What is incomprehensible to them is that being kadaver gehorsam (to use the extreme Prussian term for following orders) actually requires great flexibility -- enough flexibility to put your own ideas and wishes aside and do something very difficult. Ask any soldier if all commands are easy to obey.

A good article on Leftist hate

The real history of social Darwinism

Some personal memoirs

Memoir highlights

THE PSYCHOLOGIST

Scientists find the human brain has grown by whopping 7% since 1930... but there are signs IQs have gone backwards in recent years

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