How would YOU know? Because, as an experimental physicist, statistical analysis is what I spend a good part of my time doing.
Misusing statistics the way the authors of TBC have, is very offensive to me.
According to the last thing written about race, by Murray, he was trying to show the futility of using certain statistical measures to measure the performance of teaching institutions in regards to racial differences in standardized testing. For example, if you say that you will modify your teaching strategies in order to equalize the average scores of different races on standardized tests, then one might never be satisfied, because statistically (I use them all the time, BTW, in my line of work as well), it can be demonstrated that there are "racial differences" in abilities. Of course, this depends on how you define "race", but as defined in most studies where racial differences are examined, it appears that you DO find differences that no amount of teaching can overcome. Those differences are in the TEST scores, get it? Not that some "Race" is "smarter" than others, but according to standardized testing, it can appear that way, so you will never be satisfied because these tests can always show a difference.
All that said, it is also apparent that I have a difficult time sometimes, making sense. Shows ya what good a 135 IQ is...