encephalization-hypothesis

This chapter argues for the necessity of a theory of cognitive evolution that accounts for the emergence of modern human mental architecture. It contrasts two main approaches to higher cognitive functions: modular theories, which propose multiple specialized cognitive modules, and unitary theories, which suggest a single general cognitive structure primarily supported by brain size increase (encephalization). The chapter highlights the evolutionary implications of these models, emphasizing the importance of continuity with ancestral forms and the biological feasibility of proposed mental structures.

The chapter traces the evolutionary increase in brain size and cognitive capacity from early primates through hominids, emphasizing the neocortex expansion as a key factor. It highlights Homo habilis as the first hominid with notable encephalization and primitive tool use, followed by Homo erectus, who exhibited significant brain enlargement, advanced Acheulian tools, complex social organization, controlled fire use, and extensive migration across continents. These developments mark critical stages in the emergence of modern human cognition and cultural complexity.