Chimpanzees Behavior 29 Psychology 11 Mammals 9 Human-animal communication 8 Animal communication 5 Ecology 5 Law and legislation 5 Sign language 5 Social behavior in animals 5 Animal intelligence 4 Bonobo 4 Cognition in animals 4 Laboratory animals 4 Human evolution 3 Psychology, Comparative 3 Research 3 Animal societies 2 Chimpanzees as laboratory animals 2 Conservation 2 Human behavior 2 Human-animal relationships 2 Intellect 2 Language and languages 2 Learning in animals 2 Primatologists 2 Sexual behavior in animals 2 Zoo animals 2 African American families 1 Anatomy 1