Social scientists have established that humans experience a U-shaped happiness curve throughout their life. Middle-aged individuals seem to be less happy than other individuals regardless of socio-cultural or economic factors. A recent study has revealed that this may be a shared pattern with great apes. Over 508 captive chimpanzees and orangutans were measured for levels of happiness. The results revealed that great apes also experience what we call a ‘mid-life crisis’. What does this tell us about our own individual happiness?