Reasonable or Racist?

I've just read an article in this month's Scientific American about the IQ scores of black people. It says that black people tested around the world show an average IQ score that is fifteen points lower than the average IQ score of white people. Some researchers say this gap is narrowing, others say it isn't, but all say that there is definitely a sizable gap. The question is, Why? Is it because blacks, on average, don't eat as well as whites, have poorer health than whites, or have a less intellectually enriching environment than whites? Is it because blacks, on average, inherit genes that account for their lower IQ scores? Or is it some combination of these factors? If the IQ disparity is all or mostly acquired, why is it? That is, why is the black diet, on average, worse than the white diet, or black health worse than white, or the black environment more intellectually impoverished than the white? If it's genetic, what accounts for this genetic discrepancy? If it's a combination of these factors, what percentage does each play in the mix, and how do these various acquired and innate factors interact to produce their effect? And what, if anything, can and should be done to change things and narrow if not eliminate the gap?

Many would say that it's wrong and even egregiously racist to even talk about this issue, much less to research it in depth. Not long ago, I would have agreed with them to the point where I would have never posted an entry like this in a personal blog or written or talked about it anywhere else, and I would have probably criticized if not condemned anyone who did or who conducted scientific research on it. Now I'm uncertain of what to do. Uncertain enough not to dwell on the matter at great length. But also uncertain enough to say something about it instead of abstaining entirely.

Yet, what this entry is about, far more than it's about apparent IQ differences between races, is the broader philosophical issue of which subjects or issues one should be free to consider and publicly discuss and which not, and how we determine the difference between the two. And I pose these questions not as a prelude to presenting answers, tentative or otherwise, but simply because, as I read the aforementioned article and thought about it, I thought of these questions to which I want to give ongoing consideration and you an opportunity to respond if you so desire.