This paper reviews recent and continuing research undertaken in eastern Africa on aspects that characterize proto-human behavioral patterns. Flaked stone from amongst other places, Olduvai Gorge, Tanzania, and Koobi Fora, Kenya, represent some of the earliest definite signs of modification of natural materials for use as tools. Fossil fauna from these sites show cut marks and other modification, which establish that hominids were using stone tools on animal tissues as early as the Lower Pleistocene; that hominids acquired meat based foods through scavenging rather than hunting; and that hominids and carnivores were in competition for carcasses and/or bones. Presently, there is no indisputable archaeological evidence for Plio Pleistocene hominid deliberate construction of habitation shelter. However, it is possible that Oldowan hominids may have used their most sophisticated organizational abilities in activities such as foraging, social relations or communication, but employed only simple organizations in the actual manufacture of stone tools.