[danharaj]

Heritability is a relative measurement. You need to know what environmental factors you are controlling for in order to measure it. Because we live in societies that are highly stratified based on attributes that are genetically linked there can be environmental effects on intelligence that are difficult or impossible to correct for that create a correlation between genetics and intelligence.

[burkaman]

I know, that's why I linked to an article written by scientists that understand that, with hundreds of references to actual studies. The article goes into a lot of depth about what they mean by heritability, what genes are involved and how they are involved, what studies have led to these conclusions, etc.

The section titled "Intelligence brings (some) genetics to ‘social’ epidemiology" addresses your concerns about environmental factors.

I don't think it's very controversial to say genes contribute to intelligence. Genes contribute to everything, how could they not affect intelligence? This isn't eugenics, nobody is saying we should (or could) use this information to selectively breed humans, and nobody is saying intelligence can be correlated to race.

[danharaj]

I get what you're saying. I don't think it's contentious to say genetics influence intelligence. One thing that I strongly disagree with about the way intelligence research is done is that it seems highly based on tests of individual intelligence. There's no IQ test for groups of people.

We know that selection happens at the level of genes, not individuals. You can't measure the fitness of genes by evaluating their effects solely on individuals because their effects may involve ensembles of individuals. Since humans are highly social beings, I'd expect our genes to be selected for intelligence at the level of cooperating brains as well as individual brains. There doesn't seem to be much research on measuring this aspect of intelligence.