TABLE 2.

Psychological models of animal communication including the signal origins, the signaler’s intention, the recipient’s decoding, and the cumulative requisite cognitive skills (later models include those of previous ones).

Model	Signal origin	Signaler’s intention	Recipient’s inference	Cognitive skills
Intentional Communication	Phylogenetic ritualization Ontogenetic ritualization	I want her to do X for me	n/a (I will do X to her)	Goal-directed signals Intentionality Referentiality Awareness of informational transmission
Inferential Communication	Inference	I want her to do X(= x1 + x2 + x3) for me	What does she want me to do to her?	Prosociality Informative intention
Ostensive Communication	Conventionalization Imitative learning	I want to tell her to do X for me	What does she want to tell me to do to her?	Communicative intention Recursive mental states/3rd- and 4th-order theory of mind

A key aspect of inferential communication is that the signaler creates a new signal (or modifies an existing one) to instruct the recipient what to do. X(= x₁ + x₂ + x₃) is meant to indicate that the signaler provides not just information about their goal, but also instruction about how to do a particular action. Bold lettering in the signaler and recipient column indicates the new component in each model compared to the previous one.