Human turn-taking flexibility far exceeds fixed animal signaling because it spans varied contexts.

Evidence

Many other animals show abilities for highly structured turn-taking as in mating or display behavior, but these are highly fixed and cue bound. Human turn-taking requires enormous flexibility over a range of circumstances. Not only language, but music, dance, and nonverbal expression (overt and subtle) are involved in the coordination of meaning and action. — Roderick M. Kramer, Geoffrey J. Leonardelli, Robert W. Livingston, Social Cognition, Social Identity, and…, 415

Categorization

• XREF: Coordinate flexibility in turn-taking vs. fixed animal display anticipates the distinction between rigid ingroup scripts and flexible outgroup interaction.
• corroborated: 2 independent passages support this claim — Roderick M. Kramer, Geoffrey J. Leonardelli, Robert W. Livingston, Social Cognition, Social Identity, and…, 415