Chimpanzees in Ivory Coast Combine Vocalizations with Syntax-like Structures

Deep in the Ivorian forests, chimpanzees, our closest evolutionary relatives, are showing precursors to human speech. A new study reveals their ability to combine vocalizations in a syntax-like manner. Researchers from the Max Planck Institute for Evolutionary Anthropology and the Lyon Neuroscience Research Center observed three chimpanzee communities in Taï National Park, Ivory Coast. They analyzed over 9,000 vocalizations, identifying 12 individual call types combined into at least 16 different forms. These combinations weren't random; chimpanzees modified or expanded the meaning of their calls. Some combinations were compositional, adding the meaning of both elements (e.g., "feeding + rest"). Others were idiomatic, generating new messages impossible to decipher from their parts (e.g., "rest + affiliation" resulting in "nesting"). This communication structure resembles how humans construct sentences with syntax. Cédric Girard-Buttoz, the study's first author, stated, "Our results indicate a generative vocal system in chimpanzees, something that has not been observed with such clarity in any other animal." The discovery has significant evolutionary implications. If chimpanzees can combine sounds to express complex ideas, their common ancestor with humans likely had sophisticated combinatorial abilities. This vocal vestige could be the seed of human language. Roman Wittig, director of the Taï Chimpanzee Project, emphasizes the need to preserve these communities. Catherine Crockford, a senior author, highlights the need to reframe questions about language. She asks, "If we combine sounds to form complex meanings, and chimpanzees also, how unique is our linguistic ability?"