Why St Elmo's fire can warn of lightning

People in Britain and the United States both speak English, but their major sign languages developed along different historical paths. British Sign Language and American Sign Language have different vocabulary and grammar, so knowing one does not automatically let someone understand the other. Sign languages are independent natural languages, not spoken English translated into gestures.

Carl Linnaeus organized humans into geographical varieties in his influential classification of nature. Later versions associated these groups not only with physical traits but also with supposed differences in temperament and behavior. Such descriptions helped give cultural prejudices an appearance of scientific authority, contributing to the history of racial classification.