A chimpanzee is not a bodybuilder. A typical adult male weighs around 60 kg — about the same as a lean adult man, sometimes less. Yet when a chimp and a human collide, the fight isn't close, and it isn't close by a wide margin.
In 2009, a pet chimpanzee named Travis, who weighed roughly 90 kg — heavy for a chimp, unremarkable for a human male — attacked a woman named Charla Nash in Stamford, Connecticut. Paramedics compared the scene to a car crash. Nash lost both hands, her nose, her eyelids, and most of her facial structure, and survived only because of an extraordinary trauma response and, years later, a face and hand transplant. Travis was shot dead by police at the scene after continuing to attack an officer's patrol car.
This wasn't a freak outlier. Every documented case of a captive chimp attacking a caretaker or visitor — and there are dozens on record — follows the same pattern: catastrophic, almost surgical tissue destruction, delivered by an animal that a strong human could plausibly out-bench-press.
So here is the real puzzle, and it's a better one than "why are chimps so strong": why are humans, of all animals, so specifically and deliberately weak?
The answer