Humans evolved to get better sleep in less time. Duke Today, Dec. 14, 2015. Insomniacs take heart: Humans get by on significantly less sleep than our closest animal relatives. The secret, according to a new study of slumber patterns across 21 species of primates, is that our sleep is more efficient. Picked up by The New York Times, The Washington Post, TIME, the Daily Mail, BBC, Huffington Post, WPTV, News & Observer, Futurity, U.S. News & World Report and Voice of America.