Recent researches in neurosciences and comparative primatology have reinforced appreciation of the importance of object manipulation and artefact use in the shaping of human intelligence, especially in the social contexts of shared knowledge. Archaeology has datasets of primary significance, which allow us to chart developments through time, and particularly the emergence or enhancement of shared concepts. When early Pleistocene artefacts are studied in sets, they exhibit some deep regularities that appear to show the operation of particular principles or concepts. The chapter uses African Acheulean datasets applying Principal Components Analysis (PCA) to explore the extent to which deeply seated elements of design form recur, whether under cultural control or reinforced by functional constraints. It highlights particular evidence that points towards shared activities and shared perceptions of rules, and the nature of the communications involved. The data are taken from sites ranging across Africa – Casablanca in the north, Kariandusi, Kilombe and Baringo in Kenya, and from two sites at Kalambo Falls in Zambia. The biface sets were measured by up to 11 variables. In general, three principal components emerge, with very similar characteristics. They indicate that the toolmakers tended to handle thickness separately from planform, to keep the butt region of the biface less variable than other areas, and to pay particular attention to the tip thickness. As this pattern is maintained almost regardless of the specific tool-form (hand-axe, cleaver, pick) and of site age, technology and refinement, it appears that the underlying concepts were strongly reinforced by external experience, as well as cultural tradition.