Erica Cartmill

Erica Cartmill is an anthropologist and cognitive scientist at Indiana University whose interdisciplinary work spans animal behaviour, comparative cognition, and the evolution of communication. She is best known for reframing play, teasing, and humour in great apes as a serious window on the social mind.

Cartmill began by studying gestural communication in orangutans and language more broadly — long treated as the bulwark dividing humans from other animals. Her central claim inverts the old ladder of intelligence: there is no linear scale rising towards human perfection, only a unique constellation of abilities in which humans assemble pieces — syntax, reference, cooperation, planning — that exist singly in other species but nowhere else all together. Over the last several years her research has centred on playful teasing as the evolutionary root of humour, and on building biometric measures of positive emotion (laughter, thermal signatures of arousal, optimism tests) in kea parrots, dolphins, and great apes. She founded and directs the Center for Possible Minds (with Jacob Foster), runs the Diverse Intelligences Summer Institute, and is opening a canine cognition lab at Indiana University; her citizen-science project observinganimals.org collects public reports of animals teasing.

Core positions

Cartmill holds that cognitive strengths are niche-shaped and unequal even within the great apes — chimpanzees and bonobos excel at reading social relationships, orangutans at patient material manipulation — so no single ability marks the human difference. She treats teasing as a grey zone between aggression and play whose structure (set up an expectation, then violate it) is the architecture of a basic joke, and reads it as social hypothesis-testing: a low-stakes way to probe how far a specific relationship can be pushed, and an honest signal of how much a partner values the bond. On artificial intelligence she argues that comparative and developmental methods — built for subjects who cannot be simply asked why they acted — should discipline claims about LLM understanding: a fluent verbal answer cannot be taken at face value, and these are problems no amount of algorithmic engineering will resolve.

In the wiki

• Erica Cartmill on Animal Minds, Play and Teasing, and Comparative Cognition — Sean Carroll’s Mindscape #346 (9 March 2026): the constellation view of intelligence, unequal cognition across the great apes, playful teasing as proto-humour and social hypothesis-testing, laughter and the biometrics of positive emotion, and animal-cognition methods as a discipline for probing whether LLMs understand