Cognition is readily seen to be connected to evolution through plots of the ratio of cranial capacity to body size of hominids which show two regions of sharply increasing ratios beginning at 2.5 and 0.5 million years ago – precisely the critical times inferred by the author from his study of tools. A similar correlation exists between current human brain growth spurts and the onsets of the Piagetian stages of reasoning development. The first goal of the author's target article is stated to be “to make a case for the relevance of archeological contributions to studies of the evolution of cognition” (sect. 1, Introduction). His analysis focuses on spatial cognition.