Working-Memory Capacity and the Evolution of Modern Cognitive Potential Implications from Animal and Early Human Tool Use

Tool use is the main database to track down behavioral developments in the archaeological record and thus human evolution. Working-memory capacity and modern cognitive potential, however, are no simple and obvious characters in tool behavior. Coded in cognigrams, which allow a direct comparison, animal and human tool use can be examined for specific aspects of the working-memory capacity. Detailed studies of tool behavior of wasps, sea otters, bottlenose dolphins, and chimpanzees are presented and compared with the manufacture and use of Oldowan tools and Lower Paleolithic spears. Although this shows a wide range of problem-solution distances, problem solving in animals seems to be restricted to problem complexes for which a solution can be found in spatial and temporal vicinity. In human evolution, the complexity of tool behavior increases regarding the number of active foci managed at a time in an action, the number and diversity of operational steps in a problem-solution complex, and the spatial and temporal frame in which solutions are sought. The results suggest a gradual development of the different aspects of a complex capacity instead of a late introduction of a closed phenomenon with only different facets.