Three ground-breaking studies on family lives of great apes... our nearest and dearest

From mother and baby bonds to linguistic traits, animal studies have helped us understand many of the peculiarities of human behaviour

Orangutan mothers carry their offspring for years to help them develop, but some mothers do so for longer. Picture: Eric Balke 

Homo homini lupus est — man is a wolf to man

Diogenes, ‘the Cynic’, rejected convention and lived in a barrel. According to historian Frederic Copleston, he did in public "what it is generally considered should be done in private — and even what should not be done in private".