>>13029886Your population determines an extremely large part of your IQ. Since their population is average 85, a black person with 120 IQ is much more likely to exist at the population "maxima" for their group, i.e. no matter how many 120 IQ black people you mix together, you generally wont go above that until you find new genes to increase intelligence (through mutations). Essentially the genepool has been exhausted, the 120 IQ individual is homozygous for every intelligence increasing gene that could possibly exist in the black population, at least at frequencies of .25% or above.
Conversely a 100, and even a 125 IQ white person is nowhere near their population theoretical maximum. They exist as the product of hundreds of genes which both increase and decrease intelligence balanced together, they can be heterozygous for intelligence increasing genes, which in that case their children have the potential to be more intelligent than them.
These intelligence decreasing genes exist for a reason, not all genes are equal. A black person with 120 IQ could have a prohibitively large head or something, or a highly increased risk of schizophrenia, or something else which could cause problems. A difference of 3-4 IQ points is tenable in arguments of whether a group is subhuman or not, such as comparing whites with asians, because at least they're genetically comparable (i.e. approximately similar gene intelligence gene frequencies), you're going to get individuals with at least approximate abilities at the extremes. A difference of 15 IQ points renders populations completely incomparable in terms of every single possible individual that could come out of either. Example: Jews average 115 IQ, go ahead and look up with list of Abel prize winners and tell me how many jewish people you see, or the list of Jewish American mathematicians.
