I didn't down vote, but the inherent bias in the test is a possible reason but even with that factored out, the relevance is a more reasonable objection. We're not talking the difference in between being able to grock quantum physics or not, we're talking a few questions on the exam. And IQ happens to be a pretty sweet bell curve, so if you're an average white guy, then you're still dumber than 49% of the black guys out there, and dumber than 54% of Chinese guys.
So we should give up on Africa because the average black guy didn't answer the 2 train question correctly? Should we also give up on Europe and North America because the white guys didn't answer that correctly either?
The use of this stat, were it even possible to be accurate, really only serves racists. No meaningful outcome could result from the number.