ADD Health interviewers judged the skin color of respondents as black, dark brown, medium brown, light brown, or white. Limiting the sample to just African Americans, let's treat the measure as a rough indicator of the amount of European ancestry. Here is mean educational level by skin color (sample size = 1,211):
Mean educational level
Dark brown 13.0
Medium brown 13.3*
Light brown 13.5*
*significantly higher than black category
Medium- and light-brown blacks are significantly more educated than black-skinned African Americans. White blacks--only 16 respondents--are the exception to the trend.