Is IQ really quantifiable and measurable and is it comparable across different people, different geographies and races? I didn’t think it was, may be I am wrong. How is IQ even defined?
The landmark study by Herb Needleman on the link between lead exposure and IQ only studied white children to reduce any doubts about the validity of its claims [1].
[1] https://www.wnycstudios.org/podcasts/radiolab/articles/g-pro...