Bonobo Communication: Study Reveals Human-Like Language Compositionality

A new study published in *Science* reveals that bonobos, who share 98.7% of their genome with humans, possess the ability to combine vocalizations in a way that resembles human language compositionality. This capacity, previously considered unique to humans, involves creating complex messages by combining individual vocalizations. Compositionality, in linguistics, refers to the principle where the meaning of a combination of elements is derived from the meanings of its individual parts and the rules used to combine them. Mélissa Berthet, from the University of Zürich, conducted research at the Kokolopori Bonobo Reserve, where she observed bonobos, recorded their vocalizations, and documented the contexts in which they occurred. Her analysis revealed patterns, such as a specific vocalization consistently followed by group movement, likely indicating 'let's travel.' The research team identified 11 types of individual vocalizations and analyzed 38 combinations of two calls. They found that bonobos adhere to a simple version of compositionality. In some cases, the combination results in a sum of meanings, while in others, one element modifies the other. For example, a combination of a howl (call to unite) and a high-pitched hoot (pay attention) results in a call to coordinate movement. Whistles and whispers often appear in contexts of social intimacy. Simon W. Townsend, also from the University of Zürich, suggests that the presence of compositionality in humans, chimpanzees, and bonobos indicates that their last common ancestor, living approximately seven million years ago, possessed basic compositional abilities. The study, published on April 3, 2025, suggests that the ability to construct complex meanings from smaller vocal units existed long before human language emerged.