5 ms·

How much of IQ do you think is correlated to genetics?

sillysaurus3 9y ago
It's a politically-charged question, so people tend to be very careful to ensure that whatever they say is correct. It's probably difficult to give a convincing argument in the space of an average HN comment.
- berberous 9y ago
  Is linking genetics to intelligence politically-charged, or just linking race to intelligence?
  - sillysaurus3 9y ago
    Why not take a guess and see what happens?
andrewprock 9y ago
Given that the definition of IQ is built upon constantly shifting sands, it's really hard to say.
maroonblazer 9y ago
According to this study[0] - and if experts are to be believed - it's not zero (in the case of B-W differences). "Around 90% of experts believed that genes had at least some influence on cross-national differences in cognitive ability." [0]http://journal.frontiersin.org/article/10.3389/fpsyg.2016.00399/full http://journal.frontiersin.org/article/10.3389/fpsyg.2016.00...
lacker 9y ago
According to the NIH: Researchers have conducted many studies to look for genes that influence intelligence. Many of these studies have focused on similarities and differences in IQ within families, particularly looking at adopted children and twins. These studies suggest that genetic factors underlie about 50 percent of the difference in intelligence among individuals. https://ghr.nlm.nih.gov/primer/traits/intelligence https://ghr.nlm.nih.gov/primer/traits/intelligence So, going with the NIH, I'd say about half.
haihaibye 9y ago
https://media.springernature.com/m685/springer-static/image/art%3A10.1038%2Fs41539-017-0005-6/MediaObjects/41539_2017_5_Fig1_HTML.jpg https://media.springernature.com/m685/springer-static/image/...
Symmetry 9y ago
Well, if you compare any human child with a snail you'll find that the human does almost infinity better at answering questions on IQ tests so we could say it's all genetic. Or we could take a sample of humans and feed the control group but not the other group over a course of a few weeks and see that environment plays a huge role. But over the range of upbringings we see in the US and genotypes we see in the US it's more genetic than not. But that doesn't mean that that's true across the globe. If some dirt farmer from a place with no iodine in the salt, no folate in the bread, and no access to modern public health, medicine, or schooling comes to the US their kids will tend to have an IQ something like 20 points higher.
gwern 9y ago
Somewhere around 70-80% of variance. People citing 50% as being conservative and generally ignoring measurement error and the heritability increasing with age. The latest GCTA methods, expanding the genetics considered but still far short of all genetic effects, turn in a lower bound of ~50% ("Genomic analysis of family data reveals additional genetic effects on intelligence and personality" http://biorxiv.org/content/early/2017/02/06/106203 http://biorxiv.org/content/early/2017/02/06/106203 , Hill et al 2017; "Comparison of methods that use whole genome data to estimate the heritability and genetic architecture of complex traits" http://biorxiv.org/content/early/2017/03/10/115527 http://biorxiv.org/content/early/2017/03/10/115527 , Evans et al 2017), so the true figure is definitely going to be much higher.

It's a politically-charged question, so people tend to be very careful to ensure that whatever they say is correct. It's probably difficult to give a convincing argument in the space of an average HN comment.

berberous 9y ago
Is linking genetics to intelligence politically-charged, or just linking race to intelligence?
- sillysaurus3 9y ago
  Why not take a guess and see what happens?

andrewprock 9y ago

Given that the definition of IQ is built upon constantly shifting sands, it's really hard to say.

maroonblazer 9y ago

According to this study[0] - and if experts are to be believed - it's not zero (in the case of B-W differences). "Around 90% of experts believed that genes had at least some influence on cross-national differences in cognitive ability." [0]http://journal.frontiersin.org/article/10.3389/fpsyg.2016.00399/full http://journal.frontiersin.org/article/10.3389/fpsyg.2016.00...

lacker 9y ago

According to the NIH: Researchers have conducted many studies to look for genes that influence intelligence. Many of these studies have focused on similarities and differences in IQ within families, particularly looking at adopted children and twins. These studies suggest that genetic factors underlie about 50 percent of the difference in intelligence among individuals. https://ghr.nlm.nih.gov/primer/traits/intelligence https://ghr.nlm.nih.gov/primer/traits/intelligence So, going with the NIH, I'd say about half.

haihaibye 9y ago

https://media.springernature.com/m685/springer-static/image/art%3A10.1038%2Fs41539-017-0005-6/MediaObjects/41539_2017_5_Fig1_HTML.jpg https://media.springernature.com/m685/springer-static/image/...

Symmetry 9y ago

Well, if you compare any human child with a snail you'll find that the human does almost infinity better at answering questions on IQ tests so we could say it's all genetic. Or we could take a sample of humans and feed the control group but not the other group over a course of a few weeks and see that environment plays a huge role. But over the range of upbringings we see in the US and genotypes we see in the US it's more genetic than not. But that doesn't mean that that's true across the globe. If some dirt farmer from a place with no iodine in the salt, no folate in the bread, and no access to modern public health, medicine, or schooling comes to the US their kids will tend to have an IQ something like 20 points higher.

gwern 9y ago

Somewhere around 70-80% of variance. People citing 50% as being conservative and generally ignoring measurement error and the heritability increasing with age. The latest GCTA methods, expanding the genetics considered but still far short of all genetic effects, turn in a lower bound of ~50% ("Genomic analysis of family data reveals additional genetic effects on intelligence and personality" http://biorxiv.org/content/early/2017/02/06/106203 http://biorxiv.org/content/early/2017/02/06/106203 , Hill et al 2017; "Comparison of methods that use whole genome data to estimate the heritability and genetic architecture of complex traits" http://biorxiv.org/content/early/2017/03/10/115527 http://biorxiv.org/content/early/2017/03/10/115527 , Evans et al 2017), so the true figure is definitely going to be much higher.