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Polygenic scores are measures of the contributions of many genes to hereditability, what else do you think they are? There are two questions here: 1) What gen

by pcrh 5y ago

Polygenic scores are measures of the contributions of many genes to hereditability, what else do you think they are? There are two questions here: 1) What genes contribute to human intelligence? Evidently there are some, as the structure of the brain humans are uniquely endowed with at birth is mostly determined genetically. 2) Do common variations in these genes contribute to common variations in human intelligence? For 2) the answer is categorically "a few percent at most", even according to the sources you provide yourself. It's pointless denying this fact. Repeating that ~80% of variation in intelligence is genetic is displaying a limited understanding of inheritance. To answer 1) it may be possible to identify those genes that contribute to intelligence by performing large scale genetic studies to identify the rare cases where a small signal is detected from one or several of these (a polygenic test, for example, as you are fond of). Once these genes have been identified, one could then in theory investigate how they function, etc, in order to better understand the genetic basis of human intelligence, but it is unlikely to help understand the basis of the difference in intelligence between individuals.

xyzzyz 5y ago
> Polygenic scores are measures of the contributions of many genes to hereditability, what else do you think they are? They are not “measures” in the same sense measuring tape is a measure of length. They are like credit scores: they are useful to predict likelihood of defaulting on a loan, but they do not give you full understanding of the entire reality on the ground. With better constructed credit scores you can get better at predicting defaults, just like Lee et al got better at predicting educational attainment than the 2-3% figure Plomin quoted. No sane person would say that Experian credit scores give you complete understanding of given persons credit ability and their future credit behavior, and no sane person will tell you that polygenic scores of intelligence/educational attainment give you complete picture of a person’s intelligence or education. Do you understand it now? If you’re still confused, try to think about this: if what Plomin meant, like you suggest, that genes only explain 2-3% of variance in educational attainment, how is it possible that only 4 years later, Lee et al exhibited PGS explaining 11-13% of variance? Have genes got 4 times stronger in 4 years? > For 2) the answer is categorically "a few percent at most", even according to the sources you provide yourself. No, it is not. I encourage you to put some effort into understanding what is being talked about here.

by pcrh 5y ago

xyzzyz 5y ago

> Polygenic scores are measures of the contributions of many genes to hereditability, what else do you think they are? They are not “measures” in the same sense measuring tape is a measure of length. They are like credit scores: they are useful to predict likelihood of defaulting on a loan, but they do not give you full understanding of the entire reality on the ground. With better constructed credit scores you can get better at predicting defaults, just like Lee et al got better at predicting educational attainment than the 2-3% figure Plomin quoted. No sane person would say that Experian credit scores give you complete understanding of given persons credit ability and their future credit behavior, and no sane person will tell you that polygenic scores of intelligence/educational attainment give you complete picture of a person’s intelligence or education. Do you understand it now? If you’re still confused, try to think about this: if what Plomin meant, like you suggest, that genes only explain 2-3% of variance in educational attainment, how is it possible that only 4 years later, Lee et al exhibited PGS explaining 11-13% of variance? Have genes got 4 times stronger in 4 years? > For 2) the answer is categorically "a few percent at most", even according to the sources you provide yourself. No, it is not. I encourage you to put some effort into understanding what is being talked about here.