ILLUSTRATION BY STANLEY CHOW
Mama’s Last Hug: Animal Emotions and What They Teach Us About Ourselves by Frans de Waal (Granta, £14.99)
On YouTube there is a moving clip of a brief encounter between a dying chimpanzee called Mama, and the Dutch biology professor Jan van Hooff. The two had known each other for over 40 years. At the beginning of the clip, we see Mama curled up in the foetal position.