Cultural traditions, including the passing on of complex technological knowledge, have driven the behavioral diversity of our species, and ability to thrive in many distinct environments. Reliance on culture also likely influenced and was influenced by other aspects of human biology, including life history and brain size. However, the evolutionary history of cumulative culture is not well understood. Claims range from it being present only in modern humans, to it being shared across hominins and other animal species.  To trace the development of cumulative culture, this talk will discuss changes in the complexity of stone tool technologies spanning the past 3 million years of hominin evolution. These patterns are then compared to several baselines: degrees of technological complexity achieved by chimpanzees, and other primates who likely lack cumulative culture, as well as what humans in controlled experiments have achieved without the help of culture. By about 600 thousand years ago, hominins were relying on technological behaviors that were more complex than any of these baselines. This, and a synthesis of other lines of evidence, suggest that cumulative culture had developed by then. Such a time frame could provide us a better understanding of how other changes in hominin brain size, life history, and other aspects of biology and sociality, relate to the development of cumulative culture. Finally, I will discuss the challenges of collecting and analyzing data on stone tool technologies across many sites both in a reproducible and reliable manner, and some suggested solutions.