Humans and chimpanzees share 96 per cent of the same DNA, yet how do we view our closest biological relatives? Our relationship with apes is recorded as far back as Aristotle, and various mentions appear in the Bible. Yet despite the publication of Darwin's theory of evolution in 1859, very little factual scientific information was known about chimpanzees until the early part of last century, when psychologists Wolfgang Khler and Robert Yerkes conducted a study focused specifically on the intellectual abilities of chimpanzees. Khler eventually concluded in Mentality of Apes, published in 1925, that: 'Chimpanzees manifest intelligent behaviour of the general kind familiar in human beings ... a type of behaviour which counts as specifically human.' CLOSE FRIENDS & RELATIVES is a heart-warming and thought-provoking portrait of primates from multi-award-winning photographer Bob Elsdale.