Fact #1: It's not actually obvious what IQ scores measure, what amount of cultural bias the scores have and does it even make sense to compare IQ scores between different populations. Well, it's a number so yes, you can numerically compare it, but - as we engineers would put it - it's not obvious that the scalar value of 'IQ' has the same dimension in disjoint populations.
There are various attempts to map human beings mental capabilites on various basis functions (IQ, Briggs-Meyers etc.). From the point of view of armchair natural scientist none of the the approaches are very convincing as hard core analysis tools. As facilitation tools they can provide value, but facilitation always includes discussion and holistic analysis of what actually the number means in each situtation.
Fact #2: Tatu Vanhanen has quite a lot of publicized work where he expresses views that are quite openly racist - veiled in a thin cloack of pseudoscientific analysis. It appears that he starts from the theory that some populations have higher IQ:s and then he massages the numbers until he can "prove" his original hypothesis of bias between some populations. I will not trust any number that man quotes because figuring out who he computed it would be a waste of time. IMHO, YMMV and so on but this has been his way or working for at least three decades. So, yes, crackpot radars ahoy.
Although it would be cool to pat oneself in the back and say yes, we finns are really smart... seeing Vanhanens work quoted here makes me actually a bit shamed.