0220 Okay, Tomasello’s shared-intentionality hypothesis fits, like a hand, into the glove of the exemplar sign.

The exemplar sign is embedded within the situation and perspective levels of the scholastic interscope for the way humans think.

0221 What are the implications in terms of hominin evolution?

Tomasello addresses this question at the conclusion of chapter one.

To me, the first implication is that the exemplar sign contains the components that are missing within great ape cognition.

The second implication is that the exemplar sign is part and parcel of the adaptation of joint attention.  Reflective and normative characteristics of the exemplar sign adapt to the opportunities and the dangers of collaboration and cooperation with others.

0222 In contrast, the LCAs are not so much interested in whether their perceptions make sense.  They are more inclined toward individual goals.  So, an interventional sign is typically triggered as a reaction to a situation (which humans would not typically label a “judgment”, but may have the same relational structure as judgment).  Plus, the specifying sign is the bread and butter of daily life in the band.  In particular, the specifying sign addresses the question, “Should I eat this thing or not?”

0223 Chapter two is titled, “Individual Intentionality”.

Here is a diagram of the actualization of the scholastic interscope for our last common ancestor.  The sign-interpretant for the exemplar sign is missing.  The sign-object for the exemplar sign has the same relational structure as judgment, but we (modern humans) would not call it that.  The interventional sign pales in comparison to the specifying sign, because it rarely occurs and engages involuntary gestures and vocalizations.  The specifying sign reflects those cognitive features that are under voluntary control.

So, the depth of color reflects actualization of each element.

0224 This interscope manifests during the era of individual intentionality, lasting from our last common ancestor (7Myr) to the start of bipedalism, coinciding with the earliest appearance of the southern apes (around 3.5Myr).   Bipedalism emerges in the Pliocene.  The Pliocene marks a change of global environment starting a little over 5Myr.  The emergence of bipedalism opens the door to the era of joint attention (which I tentatively locate between 3.5 and 0.8Myr).

Technical note: Bipedal australopithecines and Homo were once called “hominids”.  “Hominids” are bipedal apes or humans.  The subset of these who belong to our own lineage are called “hominins”.

0225 Tomasello suggests that our lineage is forced into cooperative lifeways, by a changing environment and ecology,.  In particular, individuals foraging alone could not quite acquire enough food to survive.  But, individuals working together not only acquired enough food for themselves, they acquired enough to share with other individuals in the band.

Tomasello’s suggestion makes sense in so far as (1) the Pliocene environment and ecology are changing enough for bipedalism to evolve and (2) bipedalism must be an adaptation to seasonally rich, yet widely distributed food resources, as expected in mixed forest and savannah.