You don't need to eat lead paint to be affected by it. Just by constantly touching it you can absorb it through your skin, it can be from leaded gasoline, it can be from contaminated water like flint. Lead was also just one example. What about income disparity between different classes of people, how can it just be race if one person is able to have a higher quality of education, and more opportunities presented to them. Preference of choosing between prestigious post secondary education and not even having the option because you and your family could never afford. Societal pressures and stigmas also can affect that. While not an example of race women in the past have published books under male names because of stigma. Not an exact comparable but just an example of social stigma. Education can also be more difficult because of being in a troubled family or in a rough part of town. I think assigning all this value to race is a huge over simplification of the incredible amount of nuances and intricacies that surrounds human intelligence. Especially when IQ isn't even a proper evaluation of full intelligence in my opinion. Does it account for someone's ability to be a mechanic? What about welding or carpentry? A farmer might score way less than a university professor of say English on a IQ test but certainly the farmer knows way more about crops and livestock than the English academic. Every human is a unique individual with strengths and weaknesses that are not predetermined by ethnicity.