Human minds do not operate in isolation. From birth, our thinking is shaped by language, symbols, norms, and institutions that bind individuals into coordinated societies. Chapter 4 moves from mind to meaning, showing how individual cognition scales into culture—and how culture, in turn, reshapes the mind. The chapter reframes culture not as habit or decoration, but as the scaffolding of social life: a layered system that synchronizes perception, belief, roles, knowledge, and decision-making. Introducing a clear model that traces the path from individual cognition to collective intelligence, it explains how language creates shared meaning, how norms and institutions stabilize cooperation, and how accumulated knowledge enables societies to think and act at scale. By presenting culture as a cognitive multiplier, this chapter reveals why human intelligence is fundamentally collective. Understanding this layered architecture is essential for explaining institutions, learning, coordination, and ultimately how complex societies endure, adapt, and survive.