Précis ofOrigins of the modern mind: Three stages in the evolution of culture and cognition

Abstract

Donald maintains that there is a need for a theory of cognitive evolution. He has two propositions: (1) To test an evolutionary thesis corresponding with a "cognitive model of the transition from apes to humans", and (2) To work out "a model of higher cognitive structure that is compatible with available cognitive and neurolinguistic evidence, within conventional evolutionary constraints" (p. 14). The theory involves a multidisciplinary approach to the emergence of Homo sapiens sapiens, by taking into account data of neurology, palaeontology, ethological aspects of cognitive growth, and cultural change. The discussion is divided into nine chapters.He starts with several theories of neuropsychology and neurolinguistic that might have a bearing on understanding cognitive processes (Chapters 2 and 3). Interestingly, he pays attention to brain lesions, especially with regard to lateralization of functions. Of special interest is his discussion of the relations between semantic reference, intellectual and cognitive skill on the one hand, and language on the other. He concludes that in comparison with apes and all other animals "human skill is uniquely powerful, even in the absence of language" (p. 85), so that language alone does not underly all that is distinctly human in cognition. These two statements have important consequences for his ensuing evolutionary scenario.In Chapter 4 Donald focuses on the question of the emergence of thought and language in relation to the chronology of anatomical and cultural change. In comparison with some non-human species, human morphological characteristics (like bipedalism, opposable thumb, elaborate vocal apparatus, large brain) are not of necessity sufficient for an explanation of the emergence of language. Even the modern human supralaryngeal vocal tract cannot be considered as the cause of the emergence of speech. Such a monocausal explanation would obscure the evolutionary changes in hominid communication, whose origin depended on appropriate cognitive skills.From his discussion of bipedalism (already present in Australopithecines), encephalization (hominids in general), and the capacity for culture (Homo habilis, erectus, and sapiens) Donald concludes that the emergence and subsequent evolution of culture are exemplary for growing cognitive skills that were not dependent on the "recent innovations" (p. 115) of speech. His discussion covers the relation between two anatomical developments having contributed to the emergence of language and thought, namely, those of the brain and the human covcal tract. Although the former will have been fundamental for the complexification of behaviour, the emergence of culture and its subsequent evolution did no longer correspond with an increase in brain size (p. 115). Language constituted the specialized adaptation which underlaid cultural change, but, so wonders Donald, how is its emergence to be explained?He assumes that the encephalization quotient of Homo erectus paralleled a slight descent

Indexical and referential pointing in chimpanzees (Pan troglodytes).

“…To summarize, contrary to several recent claims (Butterworth & Grover, 1988;Corballis, 1991;Donald, 1991) referential pointing does occur in laboratory-reared chimpanzees in the absence of language training or explicit shaping. Furthermore, contra Povinelli and Davis (1994), referential pointing with the index finger also occurs.…”

“…This has been well documented for all four great ape species" (p. 287). Nevertheless, a number of authorities have recently claimed either that apes do not point (Butterworth & Grover, 1988;Corballis, 1991;Donald, 1991) or that apes do not point with the index finger (Povinelli & Davis, 1994). For example, Donald (1991) remarked that the putative lack of intentionality in the communicative gestures of home-reared chimpanzees is "emphasized by the absence of spontaneous pointing behavior" (p. 127).…”

“…Nevertheless, a number of authorities have recently claimed either that apes do not point (Butterworth & Grover, 1988;Corballis, 1991;Donald, 1991) or that apes do not point with the index finger (Povinelli & Davis, 1994). For example, Donald (1991) remarked that the putative lack of intentionality in the communicative gestures of home-reared chimpanzees is "emphasized by the absence of spontaneous pointing behavior" (p. 127). With respect to indexical pointing, Povinelli and Davis (1994) asserted that, in laboratory-reared chimpanzees that exhibit pointlike gestures, "pointing with the index finger does not develop, even in those subjects trained to respond to human indexical pointing" (p. 134).…”

Towards a unified science of cultural evolution

“…It may also be fruitful to study the adaptation of cultural traits to alternative transmission media such as printed documents or the Internet, and to examine whether such media are merely direct extensions of cognitive capacities or whether they generate their own novel transmission constraints (see Donald 1991).…”

Substantive Thoughts about Substantive Thoughts: A Reply to Galin

“…In particular, he argues that spoken language can be parsed into ''intonation units,'' which are generally four-to five-word phrases that convey a single substantive thought. There is some evidence that language has evolved quite recently (Donald, 1991), and neuroimaging and neuropsychological evidence indicates that many brain regions are involved in linguistic processing. Together, these results suggest that language is a composite function that developed from a number of simpler, previously nonlinguistic, functions.…”