Perishable material choice indicates symbolic and representational capacities.

The absence of symbolic material cultural objects in the archaeological record does not prove absence of symbolic cognition. Sometimes perishable materials are selected for symbolic roles, for practical concerns or to indicate a temporary condition. Also some symbolic functions may predate the use of durable materials.

Self-organization of power at will.

We challenge and extend Ainslie's top-down view of willpower as a dual function, resolve and suppression. Instead, we propose an alternative self-organizational view of the motivational system as a network of urges, incentives, drives, and so on that interact dynamically. With such a view, resolve, suppression, and other functions emerge under certain environmental and social conditions for certain personality profiles.