Yeah that's a crappy argument, IQ tests are heavily skewed for people with formal education and other "privileges". Africa has a turgid educational system hence why people there score so low. Also, Jews test for higher IQ mostly because all over the world Jews are an elite economic group with emphasis on education, in Israel where you have economic variety among Jews you'll find a wide spectrum.
so different groups might score differently but you can't conclude anything regarding the basic intelligence of group members by IQ tests