Here is a recent article about test scores from the New York Times, “No Rich Child Left Behind.” They got through the entire article without connecting cognitive abilities to inherited intelligence. Instead, the connection is made to wealth, poverty, and early childhood development. Do middle/upper class things for a child at night (“Goodnight Moon time”), and they are going to fit into the academic world created by the upper and middle classes in the schools. Goodnight Moon time in turn is highly correlated with poverty.
Note too that widening gaps between test scores for the upper 10% and the lowest 10% in terms of income have widened over the last 50 years. This in large part is because economic inequality has increased, and could not plausibly have to do with shifts in the gene pool of the last two generations (i.e. 50 years).