As an undergraduate at the University of London's Institute of Archaeology, I was taught that archaeology was ultimately about "the mind behind the artifact." It was about the person who made the ancient object I happened to be studying. That perspective seemed easy enough when I contemplated the simple chipped stones that represent most of human prehistory. The minds responsible for those artifacts, I naively thought, must have been pretty simple. But when my studies advanced to the explosion of cave art, burial relics and complex tools that signaled the appearance of modern humans more than 30,000 years ago, I just could not understand how that new mind had come to be. What could account for the radical cognitive bloom? So I asked an instructor. His cheerful, rhetorical response was quintessentially British: "They became very smart?"