The British zoologist Robin Baker points out in his book Human Navigation and the Sixth Sense that one reason the scientific belief in a sixth sense lasted for so long is that by the nineteenth century, people in western Europe had so many aids to navigation, such as maps, compasses, place-names, roads, and road signs, that they themselves had forgotten there were other strategies for navigating. This forgetting is remarkable because, as Baker wrote, these modern inventions had only been available to the masses for three or four generations at most.
