4 ms·

It's both fixed and innate. Education can stretch it a little, but it benefits more high IQs than low IQs. (It's fixed, but stretchable, and you can squeeze it

It's both fixed and innate. Education can stretch it a little, but it benefits more high IQs than low IQs. (It's fixed, but stretchable, and you can squeeze it, with stress, hunger, poverty, etc).

sametmax 8y ago
I'd like 20cc of study with that statement, given that brain plasticity can change radically the way your brain works all your life. Also, accidents can alter the brain and lower your IQ, so are you saying you can go down but not up ?
- mockingbirdy 8y ago
  > so are you saying you can go down but not up You have a specific amount of neurons and a lot of them die every day. The body doesn't produce them like other cells after a certain age threshold (age 21 IIRC, also depends on the individual). - Although this theory is currently on the edge of being disproved, it's clear that adult brains are not producing many of them. Training and experience can compensate this loss, but the general cognitive capacity gets reduced each day. Pretty depressive to think about it, but maybe we'll be able to use stem cell research to change this in the future. edit: I don't want to state this as definitive facts. The field of neurogenesis is currently heavily researched and there are some hints that adult brains might be able to produce new neurons. See https://www.scientificamerican.com/article/does-the-adult-brain-really-grow-new-neurons/ https://www.scientificamerican.com/article/does-the-adult-br... for a discussion. What I think is most likely is that we lose 10x times the amount of neurons that we create each day, so even if it's producing new ones, the rate of death is higher.
- TangoTrotFox 8y ago
  Heritability of IQ is the term you're looking for. Wiki has a page on it here [1]. The numbers have not been pinned down and it was previously thought to be as low as 57%, but recent studies tend to show heritability rates upwards of 80%. There are a lot of complex issues that make study difficult. For instance there's the paradoxical issue that childhood IQ can be somewhat meaningfully influenced by environment, yet that notwithstanding, as children approach adolescence and especially adulthood their IQ becomes ever more a product of genetics. That said environment obviously does play some role, but that role is already a minority player and seems to be getting smaller as we learn more about genetics. [1] - https://en.wikipedia.org/wiki/Heritability_of_IQ https://en.wikipedia.org/wiki/Heritability_of_IQ
  - bildung 8y ago
    From the article: "Heritability measures the proportion of variation in a trait that can be attributed to genes, and not the proportion of a trait caused by genes." If e.g. schools get better, and the whole population would have access to these better schools, everyone would be more intelligent, yet the heritability would still be at 80%.
    - TangoTrotFox 8y ago
      You've gotta be careful with Wiki at times. In that same paragraph you'll also see the sentence "Contrary to popular[citation needed] belief, two parents of higher IQ will not necessarily produce offspring of equal or higher intelligence. In fact, according to the concept of regression toward the mean, parents whose IQ is at either extreme are more likely to produce offspring with IQ closer to the mean (or average)." That literally made me laugh. Whoever wrote that has no absolutely clue what regression towards the mean is or means, yet felt qualified to write on it. The reason Wiki is useful is as a collection of sources to meaningful information and statistics. But much of what is written by Wikipedia editors themselves is often very bad, and exponentially more so when you enter into any area that could be in any way controversial -- which includes this topic. It should be taken with a grain of salt. In this case, however, the statement you mention is technically correct. But one thing you have to account for is that 20% encompasses all environmental differences. Put another way, if we all had a 100% identical upbringing and environmental factors then the heritability of any given observation would obviously be 100%, since any deviations from the norm would be primarily due to genetic factors. So that means that all of the wild variations in our upbringings and backgrounds are constrained to as little as 20% of any variation in IQ.
- 21 8y ago
  > Also, accidents can alter the brain and lower your IQ, so are you saying you can go down but not up What sort of an argument is this? You can lose an arm in an accident, does this mean you can also gain an arm?
  - sametmax 8y ago
    If you can lose mobility in an accident by making your muscle stiffer, you can game some by making it more flexible.
arethuza 8y ago
Funny how people around here are usually rather skeptical about any results in psychology apart from intelligence tests!
- AmericanChopper 8y ago
  If there's one thing in the field of psychology that is actually science, it's IQ tests. Empirically, IQ has been shown to not change much at all over time, and is the single most reliable factor for predicting outcomes that psychology has ever produced. The big 5 personality model is the next best tool psychologists have, but it's not nearly as reliable as IQ. That said, it's still not an excellent measure for basing predictions on, by the standards of "traditional" science. But if you don't put any weight in IQ, then there's nothing in the entire field that you should have any faith in.

It's both fixed and innate. Education can stretch it a little, but it benefits more high IQs than low IQs. (It's fixed, but stretchable, and you can squeeze it, with stress, hunger, poverty, etc).

sametmax 8y ago

I'd like 20cc of study with that statement, given that brain plasticity can change radically the way your brain works all your life. Also, accidents can alter the brain and lower your IQ, so are you saying you can go down but not up ?

mockingbirdy 8y ago
> so are you saying you can go down but not up You have a specific amount of neurons and a lot of them die every day. The body doesn't produce them like other cells after a certain age threshold (age 21 IIRC, also depends on the individual). - Although this theory is currently on the edge of being disproved, it's clear that adult brains are not producing many of them. Training and experience can compensate this loss, but the general cognitive capacity gets reduced each day. Pretty depressive to think about it, but maybe we'll be able to use stem cell research to change this in the future. edit: I don't want to state this as definitive facts. The field of neurogenesis is currently heavily researched and there are some hints that adult brains might be able to produce new neurons. See https://www.scientificamerican.com/article/does-the-adult-brain-really-grow-new-neurons/ https://www.scientificamerican.com/article/does-the-adult-br... for a discussion. What I think is most likely is that we lose 10x times the amount of neurons that we create each day, so even if it's producing new ones, the rate of death is higher.
TangoTrotFox 8y ago
Heritability of IQ is the term you're looking for. Wiki has a page on it here [1]. The numbers have not been pinned down and it was previously thought to be as low as 57%, but recent studies tend to show heritability rates upwards of 80%. There are a lot of complex issues that make study difficult. For instance there's the paradoxical issue that childhood IQ can be somewhat meaningfully influenced by environment, yet that notwithstanding, as children approach adolescence and especially adulthood their IQ becomes ever more a product of genetics. That said environment obviously does play some role, but that role is already a minority player and seems to be getting smaller as we learn more about genetics. [1] - https://en.wikipedia.org/wiki/Heritability_of_IQ https://en.wikipedia.org/wiki/Heritability_of_IQ
- bildung 8y ago
  From the article: "Heritability measures the proportion of variation in a trait that can be attributed to genes, and not the proportion of a trait caused by genes." If e.g. schools get better, and the whole population would have access to these better schools, everyone would be more intelligent, yet the heritability would still be at 80%.
  - TangoTrotFox 8y ago
    You've gotta be careful with Wiki at times. In that same paragraph you'll also see the sentence "Contrary to popular[citation needed] belief, two parents of higher IQ will not necessarily produce offspring of equal or higher intelligence. In fact, according to the concept of regression toward the mean, parents whose IQ is at either extreme are more likely to produce offspring with IQ closer to the mean (or average)." That literally made me laugh. Whoever wrote that has no absolutely clue what regression towards the mean is or means, yet felt qualified to write on it. The reason Wiki is useful is as a collection of sources to meaningful information and statistics. But much of what is written by Wikipedia editors themselves is often very bad, and exponentially more so when you enter into any area that could be in any way controversial -- which includes this topic. It should be taken with a grain of salt. In this case, however, the statement you mention is technically correct. But one thing you have to account for is that 20% encompasses all environmental differences. Put another way, if we all had a 100% identical upbringing and environmental factors then the heritability of any given observation would obviously be 100%, since any deviations from the norm would be primarily due to genetic factors. So that means that all of the wild variations in our upbringings and backgrounds are constrained to as little as 20% of any variation in IQ.
21 8y ago
> Also, accidents can alter the brain and lower your IQ, so are you saying you can go down but not up What sort of an argument is this? You can lose an arm in an accident, does this mean you can also gain an arm?
- sametmax 8y ago
  If you can lose mobility in an accident by making your muscle stiffer, you can game some by making it more flexible.

arethuza 8y ago

Funny how people around here are usually rather skeptical about any results in psychology apart from intelligence tests!

AmericanChopper 8y ago
If there's one thing in the field of psychology that is actually science, it's IQ tests. Empirically, IQ has been shown to not change much at all over time, and is the single most reliable factor for predicting outcomes that psychology has ever produced. The big 5 personality model is the next best tool psychologists have, but it's not nearly as reliable as IQ. That said, it's still not an excellent measure for basing predictions on, by the standards of "traditional" science. But if you don't put any weight in IQ, then there's nothing in the entire field that you should have any faith in.