Initial assumptions
It must be acknowledged first that even before environment intervenes, intrinsic, genetically transmitted features condition the kinds of culture that cultural creatures can contrive.
There is no agreement among students of the subject as to what those features are. By comparing humans with other cultural creatures, however, we can identify the traits that mark the distinctiveness (such as it is) of human culture: relative flexibility in adapting to a variety of environments and relative mutability. For two reasons, we can be sure that these traits are not simply the consequence of adjustments humans made to the diversity of the environments they colonized. First, the very impulse to traverse and occupy unfamiliar environments is itself a consequence of cultural mutability; secondly, the evidence is overwhelming that different human groups respond very differently to similar or identical environmental conditions.1The archaeological record has not so far yielded evidence of rapid cultural divergence among human groups for the first hundred thousand years or so of the existence of Homo sapiens; so the pertinent characteristics may not be of any great antiquity in evolutionary terms. For the purposes of this chapter, I make assumptions that require justification at greater length than is available at present: that the pertinent characteristics did not necessarily evolve earlier than the foraging phase of our hominid ancestors' past; that they are connected with, and perhaps account for, mental faculties that, as far as we know, feature to an exceptional degree in human psyches; that the critical mental faculty of this kind in explaining human cultural diversity is imagination; that imagination is, in evolutionary jargon, a spandrel - an unpredictable and unnecessary consequence of evolutionary change; and that it is a by-product of evolution- arily determined characteristics of two other human mental faculties: anticipation and memory.[366] [367] The power of imagination, according to my assumptions, freed human cultures to respond with extraordinary elasticity and diversity to the environments they confronted. It seems reasonable also to postulate language as a means of maintaining relatively large communities, compared with those of some other cultural creatures, and of doing innovative things with them - but we do not know when language became available, or even whether it is properly classified as a faculty, or whether it can be explained in evolutionary terms.[368]