others who worked with male and female apes of various ages to complete questionnaires on the animals. The forms included questions about each ape’s mood, the enjoyment they gained from socializing, and their success at achieving certain goals. The final question asked how carers would feel about being the ape for a week. They scored their answers from one to seven. More than 500 apes were included in the study in three separate groups. The first two groups were chimpanzees, with the third made up of orangutans from Sumatra or Borneo. The animals came from zoos, sanctuaries and research centres in the US, Australia, Japan, Canada and Singapore. When the researchers analyzed the questionnaires, they found that well-being in the apes fell in middle age and climbed again as the animals moved into old age. In captivity, great apes often live to 50 or more. The nadir in the animals’ well-being occurred, on average, at 28.3 and 27.2 years old for the chimpanzees, and 35.4 years old for the orangutans. “In all three groups we find evidence that well-being is lowest in chimpanzees and orangutans at an age that roughly corresponds to midlife in humans,” Weiss said. “On average, well-being scores are lowest when animals are around 30 years old.” The team explains that the temporary fall in ape well-being may result from watching depressed apes dying younger, or through