Are captive chimpanzee attacks on humans common?
Yeah, definitely common. Most of the time they attack through cage bars. They bite off fingers. It happens more often with people they don't know very well and people who aren't familiar with chimpanzees. But it has happened to many of the best scientists and researchers, who are now missing digits. The reason we have them behind bars in zoos and research settings is because chimpanzees can be very dangerous—it's to protect ourselves. This was a sort of free-ranging chimp, which is much more dangerous. But chimps in the wild are not used to people—they're afraid of them. That's why Jane Goodall had to habituate them. So, really wild chimps don't attack people. But in captivity, they have learned in the meantime that they are stronger than humans.