In this enlightening exploration of our nearest primate relatives, Michael Tomasello and JosepCall address the current state of our knowledge about the cognitive skills of non-human primates and integrate empirical findings from the beginning of the century to the present.
We propose that the crucial difference between human cognition and that of other species is the ability to participate with others in collaborative activities with shared goals and intentions: shared intentionality. Participation in such activities requires not only especially powerful forms of intention reading and cultural learning, but also a unique motivation to share psychological states with others and unique forms of cognitive representation for doing so. The result of participating in these activities is species-unique forms of cultural cognition and (...) evolution, enabling everything from the creation and use of linguistic symbols to the construction of social norms and individual beliefs to the establishment of social institutions. In support of this proposal we argue and present evidence that great apes understand the basics of intentional action, but they still do not participate in activities involving joint intentions and attention. Human children's skills of shared intentionality develop gradually during the first 14 months of life as two ontogenetic pathways intertwine: the general ape line of understanding others as animate, goal-directed, and intentional agents; and a species-unique motivation to share emotions, experience, and activities with other persons. The developmental outcome is children's ability to construct dialogic cognitive representations, which enable them to participate in earnest in the collectivity that is human cognition. Key Words: collaboration; cooperation; cultural learning; culture; evolutionary psychology; intentions; shared intentionality; social cognition; social learning; theory of mind; joint attention. (shrink)
Cognitive abilities cannot be measured directly. What we can measure is individual variation in task performance. In this paper, we first make the case for why we should be interested in mapping individual differences in task performance on to particular cognitive abilities: we suggest that it is crucial for examining the causes and consequences of variation both within and between species. As a case study, we examine whether multiple measures of inhibitory control for non-human animals do indeed produce correlated task (...) performance; however, no clear pattern emerges that would support the notion of a common cognitive ability underpinning individual differences in performance. We advocate a psychometric approach involving a three-step programme to make theoretical and empirical progress: first, we need tasks that reveal signature limits in performance. Second, we need to assess the reliability of individual differences in task performance. Third, multi-trait multi-method test batteries will be instrumental in validating cognitive abilities. Together, these steps will help us to establish what varies between individuals that could impact their fitness and ultimately shape the course of the evolution of animal minds. Finally, we propose executive functions, including working memory, inhibitory control and attentional shifting, as a sensible starting point for this endeavour. (shrink)
Orang-utans played a communication game in two studies testing their ability to produce and comprehend requestive pointing. While the ‘communicator’ could see but not obtain hidden food, the ‘donor’ could release the food to the communicator, but could not see its location for herself. They could coordinate successfully if the communicator pointed to the food, and if the donor comprehended his communicative goal and responded pro-socially. In Study 1, one orang-utan pointed regularly and accurately for peers. However, they responded only (...) rarely. In Study 2, a human experimenter played the communicator’s role in three conditions, testing the apes’ comprehension of points of different heights and different degrees of ostension. There was no effect of condition. However, across conditions one donor performed well individually, and as a group orang-utans’ comprehension performance tended towards significance. We explain this on the grounds that comprehension required inferences that they found difficult – but not impossible. The finding has valuable implications for our thinking about the development of pointing in phylogeny. (shrink)
Chimpanzees follow the gaze of conspecifics and humans — follow it past distractors and behind barriers, ‘check back’ with humans when gaze following does not yield interesting sights, use gestures appropriately depending on the visual access of their recipient, and select different pieces of food depending on whether their competitor has visual access to them. Taken together, these findings make a strong case for the hypothesis that chimpanzees have some understanding of what other individuals can and cannot see. However, chimpanzees (...) do not seem nearly so skillful in the Gesture Choice and Object Choice experimental paradigms. Neither behavioral conditioning nor theory of mind explanations can account for these results satisfactorily. Instead this chapter proposes the idea that chimpanzees have the cognitive skills to recall, represent, categorize, and reason about the behavior and perception of others, but not their intentional or mental states, because they do not know that others have such states since they cannot make a link to their own. Human beings began their own evolutionary trajectory with these same skills, but then at some point in their evolution (probably quite recently) they began to understand that their own experience could serve as some kind of model for that of other persons. This allowed for even better prediction and control of the behavior of others and better communication and cooperation with them as well, and so it was an adaptation with immediate adaptive consequences that ensured its survival. (shrink)
Smith et al.'s article provides a convincing argument for devoting increased research attention to comparative metacognition. However, this increased attention should be complemented with establishing links with comparative theory of mind (ToM) research, which are currently missing. I present a task in which pairs of subjects are presented with incomplete information in an object-choice situation that could be used to establish that link.
The previous studies have shown that human infants and domestic dogs follow the gaze of a human agent only when the agent has addressed them ostensively—e.g., by making eye contact, or calling their name. This evidence is interpreted as showing that they expect ostensive signals to precede referential information. The present study tested chimpanzees, one of the closest relatives to humans, in a series of eye-tracking experiments using an experimental design adapted from these previous studies. In the ostension conditions, a (...) human actor made eye contact, called the participant’s name, and then looked at one of two objects. In the control conditions, a salient cue, which differed in each experiment (a colorful object, the actor’s nodding, or an eating action), attracted participants’ attention to the actor’s face, and then the actor looked at the object. Overall, chimpanzees followed the actor’s gaze to the cued object in both ostension and control conditions, and the ostensive signals did not enhance gaze following more than the control attention-getters. However, the ostensive signals enhanced subsequent attention to both target and distractor objects (but not to the actor’s face) more strongly than the control attention-getters—especially in the chimpanzees who had a close relationship with human caregivers. We interpret this as showing that chimpanzees have a simple form of communicative expectations on the basis of ostensive signals, but unlike human infants and dogs, they do not subsequently use the experimenter’s gaze to infer the intended referent. These results may reflect a limitation of non-domesticated species for interpreting humans’ ostensive signals in inter-species communication. (shrink)
Ape species-specific communication is grounded on the present, possesses some referential qualities and is mostly used to request objects or actions from others. Artificial systems of communication borrowed from humans transform apes' communicative exchanges by freeing them from the present (i.e. displaced reference) although requests still predominate as the main reason for communicating with others. Symbol use appears to enhance apes' relational abilities and their inhibitory control. Despite these substantial changes, it is concluded that even though artificial communication enhances thought (...) and enables its expression more openly, it does not create it or modify the motivation behind communicative exchanges. (shrink)
Flack and de Waal argue that reciprocity, revenge, and moralistic aggression are important components of the social norms that exist in some non-human primates. These and other phenomena are seen as the evolutionary building blocks of human morality. Although focussing on these phenomena is a good starting point for studying the question of morality in non-human animals, they only provide a partial answer. Two other issues deserve careful attention: perception of intentions, and the distinction between using and perceiving social norms. (...) First, perception of intention is particularly important because it modulates whether retribution is justified. There is some preliminary evidence that may indicate that some primates are sensitive to the behavioural intentions of others. Second, the evidence regarding use of social norms does not necessarily imply that individuals also perceive them . This distinction seems particularly important in any comparative analysis of morality that includes humans. Currently, it is unclear whether non- human animals are capable of perceiving social norms. Future studies should devote more attention to these issues and some possible ways to investigate them are indicated. (shrink)
As Bruner so eloquently points out, and Gauvain echoes, human beings are unique in their “locality.” Individual groups of humans develop their own unique ways of symbolizing and doing things – and these can be very different from the ways of other groups, even those living quite nearby. Our attempt in the target article was to propose a theory of the social-cognitive and social-motivational bases of humans' ability and propensity to live in this local, that is, this cultural, way – (...) which no other species does – focusing on such things as the ability to collaborate and to create shared material and symbolic artifacts. (shrink)