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Abstract

Children love to play. Why do they find such a frivolous activity so pleasurable and desirable? Perhaps it is not frivolous, but instead is an adaptation designed to guide proper cognitive development in human children. To understand why, I marshal evidence from different fields to build a case for play as a central behavioral mechanism of human brain and cognitive development. I start with a discussion of human evolution, focusing on the evolution of human physiology, tool-use, the human brain, and life-history strategy, and development, and how these are all connected as an adaptive suite. The anthropological and developmental evidence suggests the existence of an extended childhood adapted to establish the skills, knowledge, and understanding necessary to become a successful hunter-gatherer. I also compare human and chimpanzee brain development, and how brain-specific genes evolved uniquely in humans to foster human brain development. I conclude with the evidence from developmental psychology that even contemporary, first-world children are born with the drive to learn and develop intellectually through play. In this framework, human play can be viewed as an adaptation that guides human brain development to produce curious, intelligent and well-adjusted adults. I close by speculating on the possibility that barriers to or constraints on play may hamper intellectual and cognitive development. I focus on the important concept of developmental decanlization as a mechanism of evolutionary mismatch. I argue that more empirical study is needed to better understand the importance of play compared to other forms of education for optimal intellectual and cognitive development.