0112 Chapter three of Tomasello’s book concerns intentional communication among great apes.

There are two broad types of significant gestures: intentional movements and attention getters.

0113 A fun example consists of one young chimpanzee raising an arm while approaching another youngster.  This is a specifying sign-vehicle (SV_s).  The sign-object (SO_s) says, “Let’s play!”

0114 Here is the specifying sign.

0115 Do chimpanzee youngsters already know this sign?

I ask because I cannot figure how the youngsters already sense what is happening_3a or the potential of ‘something happening_1a, upon the occurrence of the raised arm gesture_2a.

I can only conclude that what is happening_3a and the potential of ‘something happening’_1a are the sign-interpretant of another sign and the sign-object of that sign is the raised arm.

In order to imagine this, a perspective-level actuality_2c is needed.

0116 Here is a picture, using the scholastic three-level interscope for how humans think.

0117 I don’t know whether scholastics have a formal causality for this sign-relation.  But, I call it “the interventional sign”.  The interventional sign is odd in so far as the actuality of the sign-vehicle_2c is mental and the actuality of the sign-object_2a is a gestural action.

It makes me wonder, is the raised arm of a young, playful, chimpanzee the sign-vehicle of the specifying sign or the sign-object of the interventional sign?

Oh, the answer is obvious.

It_2a must be both.

This is the conclusion found in Looking at Daniel Dennett’s Book (2017) “From Bacteria, To Bach and Back” in Razie Mah’s blog for December 2023.

0118 Surely, the intentionality_2c of the arm raise_2a is built into the chimpanzee as a phenotypic trait.

Surely, the sign-interpretant (SI_i) of the interventional sign informs both chimpanzee youngsters what is happening_3a and the potential of ‘something happening’_1a.

0119 But, the intention is not to inform.  The intention is to play_2c.

Consequently, there is a qualitative difference between the example of the arm raise_2a for the chimpanzee (as a stand-in for the last common ancestor) and the example of [SNAKE][THERE] of the early hominin (either Australopithecus or Homo genus).