Intentionality in great ape communication

The origin and evolution of human language has often been studied by comparing our cognitive and communicative abilities with other species and especially with our closest relatives, the primates. Numerous studies have focused their efforts on intentionality in communication, trying to determine whether or not other species were able to display such ability.

Dennett (1971) described several orders, or levels, of intentionality. Imperative signals, which are consistent with first-order intentionality, are produced by the signaller in an attempt to manipulate the recipient’s behaviour (i.e. in order to make him do a specific action). Primates and even other animal species have been shown to demonstrate such capacity. Declarative signals, which are consistent with second-order intentionality, are produced by the signaller in an attempt to manipulate the recipient’s mind or state of knowledge which implies the ability to assess the recipient’s mental state. Some studies have reported apes to be able to show this kind of cognitive ability but these results have been disputed.

The main issue concerning this debate is the lack of empirical data to support either theory. The aim of my PhD project is to establish key criteria to differentiate declarative from imperative signals and to conduct experimental studies to investigate communication in chimpanzees in different contexts (presence of a dangerous animal, food foraging and intergroup encounter) to determine the level of intentionality of the signals used in these contexts.