Many gene mutations correlated with higher IQ have been identified, and while in cases of Whites and North East Asians often 50-70%+ of the population has these mutations, in case of niggers it's never higher than 10-15%. Similarly in case of detrimental gene mutations correlated with lower IQ, you will see them in single digit percentage in Whites, but over a half of niggers will have them. So while intelligent niggers are possible, they are rare spawns (and since niggers in the US are subjected to more dysgenic factors than original African niggers, these percentages look even worse for them)