There's one segment of the black population that suffers only a 9.9 percent poverty rate, and only 13.7 percent of their under-5-year-olds are poor. There's another segment of the black population that suffers a 39.5 percent poverty rate, and 58.1 percent of its under-5-year-olds are poor.
Among whites, one population segment suffers a 6 percent poverty rate, and only 9.9 percent of its under-5-year-olds are poor. Another segment of the white population suffers a 26.4 percent poverty rate, and 52 percent of its under-5-year-olds are poor.
What do you think distinguishes the high and low poverty populations? The only statistical distinction between both the black and white populations is marriage.
I tend to think that race is over-rated as a predictive factor in America. For instance, in education, they always talk about the "black-white test gap." They never talk about the "unwed mother vs. two-parent test gap." I'll bet that the latter is larger.
UPDATE: Once again, commenters cite better posts than this one. See Jason Malloy. That long post has many interesting links, including some recent thoughts of Flynn on the Flynn Effect. He thinks it's more a matter of average people getting better at answering some types of questions on IQ tests, not an indicator of improving general intelligence.