World State in Brave New World uses Sleep-learning
Brave New World is a dystopian novel by English author Aldous Huxley, written in 1931 and published in 1932. Largely set in a futuristic World State, whose citizens are environmentally engineered into an intelligence-based social hierarchy, the novel anticipates huge scientific advancements in reproductive technology, sleep-learning, psychological manipulation and classical conditioning that are combined to make a dystopian society which is challenged by the story's protagonist. Huxley followed this book with a reassessment in essay form, Brave New World Revisited (1958), and with his final novel, Island (1962), the utopian counterpart. This novel is often compared to George Orwell's Nineteen Eighty-Four (1949).
In 1999, the Modern Library ranked Brave New World at number 5 on its list of the 100 best English-language novels of the 20th century. In 2003, Robert McCrum, writing for The Observer, included Brave New World chronologically at number 53 in "the top 100 greatest novels of all time", and the novel was listed at number 87 on The Big Read survey by the BBC. Brave New World  has frequently been banned and challenged since its original publication. It has landed on the American Library Association list of top 100 banned and challenged books of the decade since the association began the list in 1990.