It’s surprisingly difficult to understand our closest living relatives. The death of Harambe the gorilla in 2016 sent shock waves around the world after a three-year-old boy clambered into his enclosure. Many behaviourists agree that the boy was in danger, and the gorilla was displaying more than just play. The child escaped unharmed, but Harambe lost his life because his behaviour indicated increasing aggression.

Misinterpretation of behaviour can be a deadly mistake. A male western gorilla named Bokito escaped his enclosure at Diergaarde Blijdorp Zoo in Rotterdam, the Netherlands, in 2007 following a perceived challenge by a regular visitor. A female guest ‘bonded’ with Bokito through the glass by holding his gaze and smiling up to four times a week, until the ape finally snapped. He scaled the enclosure walls and attacked the woman, leaving her alive but with severe injuries.

Direct eye contact may be helpful in an interview, but staring a male gorilla in the eye and displaying your teeth tells him that you question his dominance. Luckily, Bokito was tranquillised and returned to his reinforced enclosure, where he lives peacefully with his family.