StoneByStone
It's OK to Be White
Here too, 2006 PISA scores in Germany were highest in Saxony & Bavaria.
https://lesacreduprintemps19.files.wordpress.com/2012/09/roivainen.pdf
The lowest were Lower Saxony near the Netherlands.
Does Bavaria have as many Turks & Yugoslavian immigrants as Lower Saxony?
If so, then Bavarians definitely appear to be superior over Lower Saxons of the North-West.
It's hard to say if that means Bavarians are more intelligent than Lower Saxons. It could also be the living standard factor. Though it is interesting that Saxony did that well, since it's part of East Germany. But then East Germany also has much less immigration. So there are a lot of factors.
Bavaria and Lower Saxony have about the same amount of immigrants from the Balkans and Turkey, but Lower Saxony also has lots of immigrants from the Middle East.