http://www.bbc.co.uk/nature/20359229 Interesting read! I like this bit in particular 'Dr Weiss said that the similarities between humans, chimps and orangutans go beyond genetics and physiology. it was quite mind-blowing... to find it in apes” For example, they face similar social pressures and stress factors to humans. "You don't have the chimpanzee hitting midlife and suddenly they want a bright red sports car," explained Dr Weiss. "But there may be other things that they want like mating with more females or gaining access to more resources." Or maybe they want a silver sports car which will attract more females!