Like the first volume of Machiavellian Intelligence this successor is concerned with the role of social intelligence in primate evolution. The editors note ‘three principal branch points’ in primate evolution at which selective pressures for intellectual change need to be identified, of which the Homo line is the last (Chapter 1). The Homo line is characterised by ‘massive brain enlargement, and extensive stone tool use, (see p. 14). My own chapter begins by looking briefly at questions raised by this astonishing trajectory from apes to Homo sapiens sapiens. If Machiavellian social intelligence can be traced from the strepsirhine line to its greater elaboration in apes, was it further refinement of this form of social intelligence by which the apes bootstrapped themselves to fully human intelligence? If so, were there no new characteristics linked to the hominid transition? The editors suggest that this may have occurred as a legacy from ape intelligence, or as a consequence of ‘social bias’ in solving problems of survival in the changing conditions of hominid ecology. Another possibility they note is the ‘specific development of a social module or modules, independent from other modules used for non-social tasks’ (see p. 14).

What form might a ‘social bias’ have taken? How would a ‘social module’ operate? Both would seem to involve some sort of linking of cognitive processes and social interaction. Indeed primate social intelligence can be seen as the progressively effective cognitive mapping of the interdependency of own and others' actions. Here primate cognitive mapping of feeding territories (Milton, 1988) may have been a precurser of the cognitive modelling ofcontingent interaction.

It is both a hazard and a delight of anthropological fieldwork that the more completely one becomes immersed in a society and culture totally different from one's own, the more similar people seem to kin and friends at home. Despite the manifest, subtle and profound differences there is a level on which people seem to feel and act in basically similar ways. The dynamics of this dialectic between socio-cultural uniqueness and common humanity lie in part at the intersection between cultural forms and inter-personal interaction. This is an area I first explored in papers on the links between greeting, giving and constraining (1972) and on questioning (1978a). However these two problems raised more general issues concerning the inferring of intentions in interaction, and thus the significance of social roles for making interaction more predictable (1978b). Ethologists are now suggesting that primate intelligence was directly linked to the challenges of social interdependence. This insight places the problems of greeting, questioning and inferring intentions in an even wider context. What can we learn about the nature of human society by taking seriously the possibility that human intelligence is in this fundamental sense social intelligence?

It is difficult to know where to begin with such a general problem, particularly if there is a commitment to a firm empirical base. The Working Papers were essays directed at particular aspects: the implications for primate social intelligence of an emerging spoken language; the new potentiality of language for meeting the challenges of social interdependence; language and the emergence of institutionalized gender roles; language and the emergence of rules.

THE DIVISION OF LABOUR AND INVESTMENT IN PRODUCTION

Both Adam Smith and Karl Marx were fascinated by the way in which the process of production had been subdivided and specialized in eighteenthand nineteenth-century industry. Smith describes the way in which the making of pins was broken down into 18 separate operations, which could be carried out by as many workers with an astonishing 240-fold increase in productivity, using the same technique and tools (Adam Smith 1776: vol. 1, 6-7). Marx was intrigued by the different forms of cooperation which could occur in articulating the tasks separated by the division of labour. He saw this in a highly formal way, distinguishing between organic manufacture, in which the basic raw material passes through a sequence of stages in which it is converted into the finished product (pin-making would be one example), and heterogeneous manufacture. The making of a watch is used as an example here. It used to be the individual product of one craftsman. Then (in the nineteenth century) it became the social product of a large number of detail workers; there were mainspring makers, dial makers, hairspring makers, jewelled-hold makers, ruby-lever makers, case makers, screw makers and gilders. And these had numerous subdivisions: among wheel makers the makers of brass wheels and the makers of steel wheels were distinct (Marx 1954:360). No advantage was seen in bringing these processes together under one roof: there were fewer overheads with outworkers, and more competition amongst them.