How primates learn novel complex skills:

The evolutionary origins of generative planning?

Richard W Byrne

University of St. Andrews, UK

Great apes have long been considered to display more 'human-like' behaviour than monkeys, and in recent years attention has particularly focused on their abilities in responding appropriately to the mental states of others – warning only the naïve, following only the informed, teaching only the ignorant, and so on. Though limited compared with even young humans, some 'theory of mind' in great apes but not monkeys now seems clear. However, great apes do not live in environments that are socially more challenging than those of monkeys, so any cognitive superiority of great apes needs a different explanation. In the domain of feeding, great apes do face more challenging environmental pressures than monkeys. Apes' large size and specialized locomotion impose greater locomotor costs, their digestion is less able to cope with unripe fruit, and yet they face competition from the more efficient monkeys throughout their world range. That they have survived at all shows they possess some compensatory advantage, and I will suggest in this talk that it lies in their ability to understand and construct novel, skilful programs of hierarchically organized manual action-making available to them foods that monkeys cannot process. In particular, to work out the planning structure that underlies fluid behaviour it is necessary that that the behaviour be segmented into units, and then that the statistical regularities of strings of these units be detected as clues to the organization lying behind the behaviour – great apes must be able to parse visible actions. (Some suggestions as to neural systems capable of performing these component processes can already be made.) These processes may in turn have formed the building blocks of the much more abstract uses of generative planning in humans, and in particular, language.

Byrne, R. W. (1997). The technical intelligence hypothesis: An additional evolutionary stimulus to intelligence? In (Eds.) A. Whiten & R. W. Byrne (Ed.), Machiavellian intelligence II: Extensions and evaluations (pp. 289-311). Cambridge: Cambridge University Press.

Byrne, R. W., & Russon, A. E. (1998). Learning by imitation: A hierarchical approach. Behavioral and Brain Sciences, 21, 667-721.

Byrne, R. W. (1999). Imitation without intentionality. Using string parsing to copy the organization of behaviour. Animal Cognition, 2, 63-72.

Byrne, Richard W.

School of Psychology, University of St. Andrews

St Andrews, Fife, Scotland KY16 9AJ

rwb@st-and.ac.uk