Some cognitive scientists and archaeologist worked together on some ancient engravings to try to shed light on the evolution of human cognitive processes and the development of symbolic behavior.
This question is very challenging to address; human cognitive processes do not fossilize, making it very difficult to study the mental life of our Stone Age ancestors.
“Previous investigations have relied exclusively on studies of archaeological artifacts, the size and shape of cranial casts, or the mapping of genes. These are very indirect measures of human cognitive processes. While our experimental approach is also indirect in the sense that we cannot travel back in time and directly record the cognitive processes of our Stone Age ancestors, it is, on the other hand, dealing directly with those basic cognitive processes critically involved in human symbolic behavior.”