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I think what this is all saying is that we call "intelligence" requires _both_ genetics and environment. So, you have the following truth table (very simplified

by sfblah 4y ago

I think what this is all saying is that we call "intelligence" requires _both_ genetics and environment. So, you have the following truth table (very simplified obviously): * Good genetics, bad environment = bad outcome * Bad genetics, good environment = bad outcome * Good genetics, good environment = good outcome * Bad genetics, bad environment = bad outcome So, it's basically an "and" gate. I see nothing wrong with this reasoning, and it makes perfect sense to me. A couple points, however. 1. You'd still have to ask the question of which of the variables is malleable. 2. There would remain this question along the lines of, "let's say you took 1000 children from low-SES environments and put them in high-SES environments. What happens?" My recollection of the literature on this is it's somewhat sparse (because this doesn't happen that often), but that there's a strong regression to the genetic intelligence in the teenage years. BUT, even if you argue all such studies are methodologically flawed, the US government, with its $N trillion budget could easily simply run this experiment and find out what happens. Why don't people advocate to run this experiment? Edit: Just to sidestep bad-faith responses, here's how the experiment would work. You run a program where all low-SES babies put up for adoption starting on a random day become eligible for something such that high-SES families who adopt them get some massive tax break or even subsidy while raising them. They would be required to show proof they spent $Nk per year on private schools, that they live in a high-SES neighborhood the entire time, and there would be home visits to ensure the kid is being treated appropriately by the parents. Any families where this isn't the case would be excluded.

runarberg 4y ago
Before we start, Turkheimer and I disagree about the utility of IQ and the existence of general intelligence. Whereas I believe IQ is dead, and general intelligence is a made up construct, Turkheimer still believes general intelligence exists and IQ is a good way of measuring it. What Turkheimer has done however is show us a way to use IQ while not going into the race science of it. As such I think he has done a terrific job, even though I disagree with him philosophically. Now just to clarify, G + E is a different model from G + E + G×E. Many twin studies in the past century were done on a pretty homogeneous demographic, across a very slim slice of SES (mostly inside high SES; as you correctly pointed out). This skewed the models such that it completely missed the G×E part, this is, if you don’t measure across different SES, you’ll miss how SES interacts with genotypes. What Turkheimer did was actually measure heritability inside low SES, and his results were that in a G + E model, the proportions were flipped. That is, instead of G=60% and E=40%, he and his team found E=60%. When your get results that flip in this way, it is a pretty clear indicator that you have interactions between your main effects (G and E), so Turkheimer fitted a model which includes the G×E interaction[1] (which all researchers with some level of statistical literacy would do) and found that almost all of the variance previously attributed to genes, would perish into the interaction effects. You can read the study here. The methodology is not that far off from what you are proposing (just without the controlled interventions; which is bound to cause some biases anyway). https://www.researchgate.net/publication/8997472_Socioeconomic_Status_Modifies_Heritability_of_IQ_in_Young_Children https://www.researchgate.net/publication/8997472_Socioeconom... --- 1: Note the models are a bit more complicated than G+E. Usually they use an ACE model, with Genotype (A), shared environment (C), and non-shared environment (E; also known as gloomy prospect), and than model A + C + E. In Turkheimer, et. al. (2003) the model was s*SES + A*(a + a'*SES) + C*(c + c'*SES) + E*(e + e'*SES) where a,c,e are the main effects of A, C, E; s the main effect of SES; and a', c', e' are interactions of a,c,e with respects to SES.

by sfblah 4y ago

runarberg 4y ago

Before we start, Turkheimer and I disagree about the utility of IQ and the existence of general intelligence. Whereas I believe IQ is dead, and general intelligence is a made up construct, Turkheimer still believes general intelligence exists and IQ is a good way of measuring it. What Turkheimer has done however is show us a way to use IQ while not going into the race science of it. As such I think he has done a terrific job, even though I disagree with him philosophically. Now just to clarify, G + E is a different model from G + E + G×E. Many twin studies in the past century were done on a pretty homogeneous demographic, across a very slim slice of SES (mostly inside high SES; as you correctly pointed out). This skewed the models such that it completely missed the G×E part, this is, if you don’t measure across different SES, you’ll miss how SES interacts with genotypes. What Turkheimer did was actually measure heritability inside low SES, and his results were that in a G + E model, the proportions were flipped. That is, instead of G=60% and E=40%, he and his team found E=60%. When your get results that flip in this way, it is a pretty clear indicator that you have interactions between your main effects (G and E), so Turkheimer fitted a model which includes the G×E interaction[1] (which all researchers with some level of statistical literacy would do) and found that almost all of the variance previously attributed to genes, would perish into the interaction effects. You can read the study here. The methodology is not that far off from what you are proposing (just without the controlled interventions; which is bound to cause some biases anyway). https://www.researchgate.net/publication/8997472_Socioeconomic_Status_Modifies_Heritability_of_IQ_in_Young_Children https://www.researchgate.net/publication/8997472_Socioeconom... --- 1: Note the models are a bit more complicated than G+E. Usually they use an ACE model, with Genotype (A), shared environment (C), and non-shared environment (E; also known as gloomy prospect), and than model A + C + E. In Turkheimer, et. al. (2003) the model was s*SES + A*(a + a'*SES) + C*(c + c'*SES) + E*(e + e'*SES) where a,c,e are the main effects of A, C, E; s the main effect of SES; and a', c', e' are interactions of a,c,e with respects to SES.