Quote Originally Posted by xerxe View Post
No, it says exactly what I think it does. The study was explicitly testing for outgroup intermixing. They found that the effect was greater the more distantly-related the parents were.
No. Mixing a 90 IQ person with a 140 IQ person will not result in a 150 IQ child. That's not how any of this works.

Genetic distance is only desirable to a point—i.e., not marrying your cousins reduces mutational load. Beyond that threshold you risk losing valuable SNPs.