"What we are testing is whether the U-shaped curve can describe the association between age and well-being in non-human primates as it does in humans," psychologist and lead author Dr Alexander Weiss of the University of Edinburgh told BBC Nature.
An international team of researchers is suggesting that orangutans and chimpanzees might be going through a "mid life crises" aswell, just as humans.
Experiments have shown that happiness and enjoying life is rich in the younger ages of apes, they tend to be unhappy while being an "adult" but return to the state of happiness again when reaching the old age. This is the known u-shaped curve, which humans also go through.
Testings :
"Dr Weiss said that the similarities between humans, chimps and orangutans go beyond genetics and physiology. You don't have the chimpanzee hitting midlife and suddenly they want a bright red sports car. But there may be other things that they want like mating with more females or gaining access to more resources."

