The two fundamental approaches to studying human evolution are those of using data relating to the past itself (i.e., archaeology, palaeontology), and those of establishing comparative frameworks, usually based on the study of extant related species. Work with primates has been important in establishing comparisons of social structure, frameworks of subsistence, and base levels of intelligence, and has recently been used to generate ideas about the origins of language. This chapter examines how archaeology can be used to address critically the application of comparative ideas, especially those which are based on the concept of ‘Machiavellian intelligence’, linking group size and neocortex ratio. Archaeology is able to map out the communication of cultural information in a number of ways. Its direct evidence establishes that early Homo had far greater ranges than those of living apes. Technology used across these ranges had to pay for itself in energetic terms. It is argued that such factors may be as important as group size in accounting for evolutionary change.