Abstract

The social trackways theory is centered on the remarkable 3.66 mya Laetoli Fossilized Trackways, for they incontrovertibly reveal our ancestors were already obligate bipeds with very human-like feet, and were intentionally stepping in other band members’ footprints to maintain safe footing. Trackways are unique among natural sign systems in possessing a depictive narratively generative structure, somewhat like the symbolic sign systems of gestural languages. Therefore, due to daily embodied reiteration of their own and other band member’s old footprints, both for bipedal safety and as recognizable wayfinding markers for socio-ecological navigation, incrementally our Mid-Pliocene ancestors began to acquire a cognitive capacity for episodic personal memories and episodic future simulations. They began mentally representing themselves as intentional agents continuously travelling from the past into the future. This spatially and temporally self-projecting awareness manifested itself as extra theory of mind and mental space-and-time-travel capacities, which increasingly enabled intentional or conscious, top-down executive adjustment of past behaviors for the sake of achieving better ways of doing things in the future. Future-directed behavioral and cultural adaptations began to increase fitness in all domains, thus creating powerful selective feedback for further entrenchment. Here we focus on overtly or consciously intentional exploratory wayfinding and transmission of elsewhere-and-when information, using pragmatic, discursive modes of communication, which enabled far more cooperative and efficient foraging practices. Selection for better communication thus led to intentional trail marking and the earliest emergence of more conventional/symbolic depictive and gestural “protolanguages.”