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IQ is 75% heritable. That means it's 75% nature, 25% nurture.
https://en.wikipedia.org/wiki/Heritability_of_IQ
Average black IQ is 85
https://en.wikipedia.org/wiki/Race_and_intelligence#United_States_test_scores
https://en.wikipedia.org/wiki/Heritability_of_IQ
Average black IQ is 85
https://en.wikipedia.org/wiki/Race_and_intelligence#United_States_test_scores