One of the key concepts for the human part of the grand narrative of Big History is known as “collective learning.” It is one very prominent broad trend that sweeps across all human history. Collective learning to a certain degree distinguishes us as a species, got us out of Africa and the foraging lifestyle of the Paleolithic, and underpinned demographic cycles and human progress for 250,000 years. This paper looks at collective learning as a concept, its evolution within hominine species, its role in human demography, and the two great revolutions of human history: agriculture and industry. The paper then goes on to explain the connection of collective learning to Jared Diamond’s Tasmanian Effect. Collective learning also played a key role in the two Great Divergences of the past two thousand years. One is industry and the rise of the West, described to great effect by Kenneth Pomeranz; the other is the less well known: the burst of demography and innovation in Song China at the turn of the second millennium c.e . Finally the paper concludes with insights into how collective learning forges a strong connection between human history and cosmology, geology, and biology, through what is widely recognized as one of the unifying themes of Big History: the rise of complexity in the universe.