Chris Sinha, at Hunan University, publishes an article in Interaction Studies (volume 19(1-2), 2018, pages 239-255). The full title is "Praxis, symbol and language: developmental, ecological and linguistic issues".
Sinha has been working on these questions for a very long time, picking up specialized terminology along the way. He is one of the signature authors for a project called "The Road Map", which outlines a path for research into how the brain got language, using comparative neuroprimatology, among other approaches (Interaction Studies, 19:1-2 (2018), 370-387).
Sinha is one of the few to offers an alternate approach, focused on the concept that symbols are precursors to language. In this article, he intends to translate his idea into a modular EvoDevoSocio, which represents the evolution (evo-, or phylogenesis) of developmental processes (devo- or ontogenesis) adapted to social interactions (socio-, as if it is an ecological process). The modules expand to include ecology (eco-, as distinct from socio-), depending on the topic.
To me, EcoEvoDevoSocio sounds like sloganeering, rather than skeptical inquiry. So does the name of the road, "How the Brain Got Language". After all, I have never heard a brain express itself in language, until, of course, that IBM Deep Blue character that decimated all challengers on the televised game show, "Jeopardy".
Fortunately, the category-based nested form comes to the rescue with diagrams that work through Sinha's terminology-laden argument and recast Sinha's two foundational figures. Sinha's program appears to describe the evolution of hand talk within team activities (in early Homo erectus) followed by the generalization of hand talk after the domestication of fire (corresponding to later Homo erectus).
Notable, the two-level interscopes developed in these comments cohere to Gregory Sandstrom's project of Extension and Intension, as postmodern versions of the disciplines of Sociology and Psychology, although the correspondence is not exact. Sinha's work delineates adaptations in the Lebenswelt that we evolved in.
Complementary comments appear in mid-May 2021.