First, lets establish whether there is a correlation between IQ and wealth before we conclude the causation.

Now if you manage to convince me that there is a correlation, twin studies is not enough to convince me of the causation. Twin studies are controversial as they do not provide a random sample and have a number of inherit biases.

And even if you find a way to convince me that the causation is not wealth → IQ, it is still not enough to convince me that IQ causes wealth. You still have to eliminate any third variable that causes both.

This is all after you’ve convinced me that IQ is a useful and interesting metric (see nibling comments), as well as useful and unbiased, all of which is up for debate in academic studies as of yet. Good luck.

>, twin studies is not enough to convince me of the causation. Twin studies are controversial as they do not provide a random sample and have a number of inherit biases.

I wasn't talking about Twin studies. It is a fact that among adopted kids their intelligence correlates almost as much with their biological parents as for non adopted kids. Adopted kids is such a big group that there is no lack of data.

I thought it was pretty widely known that there was one. I mean, the article discusses salary vs. IQ and it should be clear that salary ends up correlating with wealth, especially if it accrues over many generations.