Scientists: Genes determine intelligence

Scientists: Genes Determine Intelligence -

Ya don't say!? I figured I was smart from all the ghetto's and country and city areas I grew up in!? Noooo! It comes from my parents? Wow!
Only a shock for Blank-slate liberals.

Heritability of IQ - Wikipedia, the free encyclopedia
[......]
Estimates of the heritability of IQ

Various studies have found the heritability of IQ to be between 0.7 and 0.8 in adults and 0.45 in childhood in the United States.[7][5][18] It may seem reasonable to expect that genetic influences on traits like IQ should become less important as one gains experiences with age. However, that the opposite occurs is well documented. Heritability measures in infancy are as low as 0.2, around 0.4 in middle childhood, and as high as 0.8 in adulthood.[8][19] One proposed explanation is that people with different genes tend to seek out different environments that reinforce the effects of those genes.[7]

A 1994 review in Behavior Genetics based on identical/fraternal twin studies found that heritability is as high as 0.80 in general cognitive ability but it also varies based on the trait, with .60 for verbal tests, .50 for spatial and speed-of-processing tests, and only .40 for memory tests.[5]

In 2006, 'The New York Times Magazine" listed about three quarters as a figure held by the majority of studies,[9] while a 2004 meta-analysis of reports in Current Directions in Psychological Science gave an overall estimate of around .85 for 18-year-olds and older.[8]
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Scientists Tie 52 Genes to Human Intelligence...
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In ‘Enormous Success,’ Scientists Tie 52 Genes to Human Intelligence
MAY 22, 2017 - In a significant advance in the study of mental ability, a team of European and American scientists announced on Monday that they had identified 52 genes linked to intelligence in nearly 80,000 people.
These genes do not determine intelligence, however. Their combined influence is minuscule, the researchers said, suggesting that thousands more are likely to be involved and still await discovery. Just as important, intelligence is profoundly shaped by the environment. Still, the findings could make it possible to begin new experiments into the biological basis of reasoning and problem-solving, experts said. They could even help researchers determine which interventions would be most effective for children struggling to learn. “This represents an enormous success,” said Paige Harden, a psychologist at the University of Texas, who was not involved in the study.

For over a century, psychologists have studied intelligence by asking people questions. Their exams have evolved into batteries of tests, each probing a different mental ability, such as verbal reasoning or memorization. In a typical test, the tasks might include imagining an object rotating, picking out a shape to complete a figure, and then pressing a button as fast as possible whenever a particular type of word appears. Each test-taker may get varying scores for different abilities. But over all, these scores tend to hang together — people who score low on one measure tend to score low on the others, and vice versa. Psychologists sometimes refer to this similarity as general intelligence.

It’s still not clear what in the brain accounts for intelligence. Neuroscientists have compared the brains of people with high and low test scores for clues, and they’ve found a few. Brain size explains a small part of the variation, for example, although there are plenty of people with small brains who score higher than others with bigger brains. Other studies hint that intelligence has something to do with how efficiently a brain can send signals from one region to another. Danielle Posthuma, a geneticist at Vrije University Amsterdam and senior author of the new paper, first became interested in the study of intelligence in the 1990s. “I’ve always been intrigued by how it works,” she said. “Is it a matter of connections in the brain, or neurotransmitters that aren’t sufficient?”

Dr. Posthuma wanted to find the genes that influence intelligence. She started by studying identical twins who share the same DNA. Identical twins tended to have more similar intelligence test scores than fraternal twins, she and her colleagues found. Hundreds of other studies have come to the same conclusion, showing a clear genetic influence on intelligence. But that doesn’t mean that intelligence is determined by genes alone. Our environment exerts its own effects, only some of which scientists understand well. Lead in drinking water, for instance, can drag down test scores. In places where food doesn’t contain iodine, giving supplements to children can raise scores.

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When Palin, Toddler Nugent, and Kid Rock were in the White House they all heard this news and thought they said jeans. "Well hell we all wear jeans so ah guess we's all gen'yusses!".
 
Scientists: Genes Determine Intelligence -

Ya don't say!? I figured I was smart from all the ghetto's and country and city areas I grew up in!? Noooo! It comes from my parents? Wow!
Only a shock for Blank-slate liberals.

Heritability of IQ - Wikipedia, the free encyclopedia
[......]
Estimates of the heritability of IQ

Various studies have found the heritability of IQ to be between 0.7 and 0.8 in adults and 0.45 in childhood in the United States.[7][5][18] It may seem reasonable to expect that genetic influences on traits like IQ should become less important as one gains experiences with age. However, that the opposite occurs is well documented. Heritability measures in infancy are as low as 0.2, around 0.4 in middle childhood, and as high as 0.8 in adulthood.[8][19] One proposed explanation is that people with different genes tend to seek out different environments that reinforce the effects of those genes.[7]

A 1994 review in Behavior Genetics based on identical/fraternal twin studies found that heritability is as high as 0.80 in general cognitive ability but it also varies based on the trait, with .60 for verbal tests, .50 for spatial and speed-of-processing tests, and only .40 for memory tests.[5]

In 2006, 'The New York Times Magazine" listed about three quarters as a figure held by the majority of studies,[9] while a 2004 meta-analysis of reports in Current Directions in Psychological Science gave an overall estimate of around .85 for 18-year-olds and older.[8]
`​

The fulcrum of the intelligence debate is Nurture v Nature.
 

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