Introduction: investigating the origins of human behaviour R.A.Foley
It is hard to find a branch of anthropology and archaeology as disparate as the study of the origins and evolution of human behaviour, which may be referred to as behavioural palaeoanthropology.
At the outset there is the question of scale. The closest living relatives of hominids are the African apes, and most probably the chimpanzee (Pan troglodytes and Pan paniscus). Current evidence suggests that the split from Pan occurred between 5 and 8 million years ago (Holmes et al. 1989). The differences between these two groups of hominoids therefore developed over a period of several million years, a timescale of unique length within anthropology (although relatively short on a general palaeontological and evolutionary scale). Such a timescale makes it very difficult to conceptualize processes over long periods, to explain long-term events, and to document the timing and sequence of the major developments. As a result, the question of whether the shift from archaic to modern hominids was of evolutionary significance in itself or whether the principal evolutionary changes occurred with the appearance of the genus Homo some 2 million years earlier (Foley 1989), for example, remains problematic.