In my earlier post on IQ trends, Steve Sailer asked if age had something to do with pattern. I don't have enough cases to do a fine-grain analysis, but I was able to split blacks and whites into under 41 and 41 and over. Looking at whites first, the prevalence of mid-level IQs grew over the past 35 years for both young and older groups at the expense of the low IQ category. The percent with high IQs (10 for 10 on the vocab test) dropped for both groups, but the younger group stayed consistenly below the older. (In fact, those 40 and under fell to zero in 2006--not perfectly accurate, I'm sure).
Black trends bounce around more due to small samples sizes. I think all we can conclude from them is that more blacks--both young and old--are in the mid-range compared to 35 years ago, and there seems to be noticeable improvement for both age groups in the past decade.