This paper provides an overview of the book chapters, which developed from a symposium on the Origins of Human Creativity and Innovation sponsored by the British Academy in September, 2009. The chapters in this book are wide-ranging, and approach these questions from many different angles, focusing on a variety of human species, study regions, and time intervals. Their papers challenge, if not break, some old paradigms. One of the ways to look at the origins of creativity and innovation is to examine the physical evolution of the human brain, facilitated in recent years through the development of 3-dimensional modelling of brain size and shape. Our Early Pleistocene ancestors had brains that were about 1/3 the size of modern human brains, but modern brain size was actually achieved by at least two other species in the genus Homo, as far back as 400,000 years ago. The various lobes of the brain associated with cognitive thought achieved various sizes and shapes in our ancestors, but there is no consensus on how this phenomenon relates to innovative thought abilities. One recurring theme in the literature is that human brain size increased as humans interacted in increasingly large societies. The social brain needs to be large.