IQ shouldn't be conflated with human worth. It should be taken as a measure of societal progress, however. Poles and Italian immigrants in the US raised their average IQ scores over the 1st half of the 20th century -- by over 15 points!
Where there has been no progress and backsliding in average IQ scores, this should be taken as an indictment of the policies at play in those times and places.
Where there has been no progress and backsliding in average IQ scores, this should be taken as an indictment of the policies at play in those times and places.