A heredetary mneonic learning disability requiring the sufferer to evaluate observed data through a filter of 19th Century Colonial beliefs regarding race and social class. Most prevalent in Australia, due to endogamous breeding and the Founder effect, and also found in England where endogamy was an 18th Century rule. Thus, the disease perpetuates itself.
The Australian sheep rancher looked over the back of his ewe just in time to see a group of Aboriginal and Irish children walking to school. Because he had Drake-Brockman he quickly identified these children as inferior and so could no longer see them. Then, he realized he was superior to the whole planet, except for the Queen, and everyone became invisible. He became lonely again and returned to his ewe.