Vocal labeling of others by nonhuman primates: A response to Jaakkola (2025).

In this commentary, we respond to Jaakkola, (2025), who raised several concerns regarding our findings on vocal labeling in marmosets (Oren et al. Science, 385, 996-1003, 2024). We address each point in turn, clarifying that marmosets use socially learned, arbitrary vocal labels for specific conspecifics - labels that are neither imitations nor acoustically derived from the receiver's own calls. We show that classifier models trained on individual callers reliably identify the intended receiver, while cross-caller models reveal family-specific label conventions. We also provide evidence that vocal accommodation does not account for the observed behavior, and we argue that the consistent, receiver-specific use of labels reflects a stable mapping between individuals and calls - indicative of an internal representation of identity. Taken together, our findings support cognitively controlled social calling in marmosets and suggest a primate precursor to name-like referential communication.