The African Middle Stone Age

The Middle Stone Age (MSA) is a period of African prehistory characterized by the production of flake-based assemblages, often with a focus on stone points and blades using prepared core reduction techniques. The MSA follows the Earlier Stone Age and precedes the Later Stone Age, although the boundaries between these periods are not as sharp as originally defined. The MSA is generally regarded as having started by at least three hundred thousand years ago (ka) and lasted until roughly forty to twenty thousand years ago. Identifying the chronological limits for the MSA is challenging because some aspects of MSA technology are found in assemblages outside this time range that also have Earlier or Later Stone Age-type tools. The earlier part of the MSA is associated with fossils belonging to the Homo sapiens clade (alternatively referred to as Homo heidelbergensis, Homo rhodesiensis, or archaic Homo sapiens). The later part of the MSA post 200 ka is associated with Homo sapiens. Determining the processes underlying the anatomical evolution of Homo sapiens during the MSA is a major aim of ongoing research, however fossil remains are rare. Across the African continent and through time, the MSA exhibits a high degree of variability in the types of stone tools that were manufactured and used. Archaeologists have used this variability to define several technocomplexes and industries within the MSA that include, but are not limited to, the “Aterian,” “Howiesons Poort,” “Still Bay,” and “Lupemban.” Variation in point styles, presumably hafted to wooden handles or in some cases projectiles, is considered a hallmark of the regional diversification that originates in the MSA. This variability, which is temporally and spatially restricted, differs in both degree and kind from the preceding Earlier Stone Age. The MSA is significant from an evolutionary perspective because, in addition to being associated with the anatomical origins of Homo sapiens, this period in time documents several significant changes in human behavior. Populations in the MSA practiced a foraging economy, were proficient hunters, and began efficiently and systematically utilizing aquatic resources such as shellfish and freshwater fish for the first time. Other significant changes include the elaboration of and increased reliance on symbolic resources and complex technologies. For example, the first known externally stored symbols in the form of crosshatched incised pigments date to ~100 ka. In contexts of similar age, shell beads for making jewelry have been recovered from Morocco and South Africa. The earliest evidence for complex projectiles dates to at least 74 ka. The meaning, utility, and persistence of symbols and complex technologies depend on social conventions and confer advantages in contexts that involve long-distance, complex social networks. While many of these earliest finds linked to behavioral modernity have so far been geographically restricted, the combined suite of genetic, fossil, and archaeological evidence may better support a polycentric African origin for Homo sapiens over the course of the MSA.