Monsters have always enjoyed a significant presence in the human imagination, and religion was instrumental in replacing the physical horror they engendered with that of a moral threat. Zombies, however, are amoral - their motivation purely instinctive and arbitrary, yet they are, perhaps, the most loathed of all contemporary monsters. One explanation for this lies in the theory of the uncanny valley, proposed by robotics engineer Masahiro Mori. According to the theory, we reserve our greatest fears for those things which seem most human, yet are not - such as dead bodies. Such a reaction is most likely a survival mechanism to protect us from danger and disease - a mechanism even more essential when the dead rise up and walk. From their beginnings zombies have reflected western societies' greatest fears - be they of revolutionary Haitians, women, or communists. In recent years the rise in the popularity of the zombie in films, books and television series reflects our fears for the planet, the economy, and of death itself