"Others tried to rationalise it by arguing non-whites are also racist" ... well, the low IQ ones must be racists if low IQ white people are.<quoted text>
Others attempted to rationalise their racism by arguing we are all naturally racists, we are born that way. Others tried to rationalise it by arguing non-whites are also racist. But none of these refutes the relationship between racism and low IQ.
There are also physiological studies, with MRI scans which support the evidence and add weight to the argument. Then there are the forums like topix. The more racist a poster, the more obvious is their lack of intellect.
IQ doesn't discriminate between skin colours!