Chimpanzee tool use demonstrates cognitive complexity that has direct implications for how we think about their welfare and the moral significance of their suffering.
The cognitive sophistication demonstrated through tool use, cultural learning, and medical self-medication places chimpanzees firmly in the category of beings with rich inner lives whose suffering is morally significant. Captive chimpanzees deprived of opportunities to use and develop tools experience cognitive deprivation that is as much a welfare harm as physical deprivation. Wild chimpanzees whose forests are fragmented lose access to the raw materials and social learning opportunities that tool culture requires, representing a cultural as well as biological welfare loss. The parallel between chimpanzee and human cultural transmission of knowledge provides a framework for understanding their welfare needs that goes beyond basic physical requirements.