...which raises the question: do these people lack the capacity for racial prejudice, or do they lack the intelligence required to determine what race a person

...which raises the question: do these people lack the capacity for racial prejudice, or do they lack the intelligence required to determine what race a person belongs to? The boundaries between races are, after all, determined by culture (a hundred years ago, Italians, Russians, and Jews would not have been considered “white”), and culture has to be learned. To make matters worse, Williams is associated with severe deficits in visual perception (http://www.udel.edu/PR/UDaily/2004/WSDrawingslg.jpg http://www.udel.edu/PR/UDaily/2004/WSDrawingslg.jpg), so it’s possible that someone with the syndrome would have trouble even recognizing the facial characteristics that neurotypical folks associate with various races.