East Asians tend to be good at a lot of things that IQ tests don't measure, or don't give a lot of weight too.

Let me give you an example. If you took a Japanese man and Jew, and during the test you told them to accurately draw everything they saw in the waiting room they had been in, including a woman who was sitting there. Then you had a hundred people who saw a photo of the waiting room vote on which looked more accurate, and just better overall, there would probably be overwhelming unanimity on which was superior, and yet you really couldnt objectively measure this, despite it being a type of intelligence. Oh yeah, and the Jap would win the vast majority of the time as Jews tend to suck at that kind of thing. They probably arent even average much less superior, but Japs excel at it. There are numerous other things that are difficult to test for that could be considered part of intelligence but aren't measured very well, or at all, on IQ tests.

Some of this probably comes through in non verbal IQ scores, but plenty of other things don't.