Even if there were a genetic switch for IQ (by our narrow definition), a eugenic program that selected for that trait would still yield inferior results to the

Even if there were a genetic switch for IQ (by our narrow definition), a eugenic program that selected for that trait would still yield inferior results to the number of outliers produced by randomness at scale. Using r/K theory as an analogy, K-selection (few, high effort offspring) works for organisms without a lot of intra-species competition, and few of those species tribalize or murder each other at any scale. r-Selection (many, low effort offspring) lack sophistication, but dominate by sheer numbers. If you started breeding modified high-IQ humans, the rest would just end up organizing to hunt them to extinction. There are others who say this has already happened.