You have shared two sources of broad, country-level data.
The study tracked localized effects on individuals.
These are not necessarily in contradiction! Though whatever you're inferring with your broad correlation (air pollution has no negative effect on intelligence? air pollution improves intelligence?) is much weaker than the study, which clearly has made attempts to isolate variables.
The study tracked localized effects on individuals.
These are not necessarily in contradiction! Though whatever you're inferring with your broad correlation (air pollution has no negative effect on intelligence? air pollution improves intelligence?) is much weaker than the study, which clearly has made attempts to isolate variables.