Asians in the U.S. traditionally scored slightly lower than whites on school-level tests except in mathematics. They caught up a couple of years ago.
Does anyone know what the literacy rate was in Korea during the 19th century? It strikes me that the bulk of variation in these test results can be explained by 19th century literacy rates (as a proxy of the strength of natural selection towards higher intelligence) plus migration patterns in the last century. Finland, for example, was one of the most literate countries of the world by 1800. But I’m not sure about Korea, it could be a major outlier.