The role of play objects and object play in human cognitive evolution and innovation

In this contribution, we address a major puzzle in the evolution of human material culture: If matur-ing individuals just learn their parental generation’s material culture, then what is the origin of keyinnovations as documented in the archeological record? We approach this question by coupling alife-history model of the costs and benefits of experimentation with a niche-construction perspec-tive. Niche-construction theory suggests that the behavior of organisms and their modification ofthe world around them have important evolutionary ramifications by altering developmentalsettings and selection pressures. Part ofHomo sapiens’niche is the active provisioning of childrenwith play objects—sometimes functional miniatures of adult tools—and the encouragement ofobject play, such as playful knapping with stones. Our model suggests that salient material cultureinnovation may occur or be primed in a late childhood or adolescence sweet spot when cognitiveand physical abilities are sufficiently mature but before the full onset of the concerns and costsassociated with reproduction. We evaluate the model against a series of archeological cases andmake suggestions for future research