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Selected Abstracts — Primate Cognition Week 11

Boysen, S.T. and Himes, G.T. (1999) Current issues and emerging theories in animal cognition. Annual Review of Psychology, 50, 683-705.

Comparative cognition is an emerging interdisciplinary field with contributions from comparative psychology, cognitive/experimental and developmental psychology, animal learning, and ethology, and is poised to move toward greater understanding of animal and human information-processing, reasoning, memory, and the phylogenetic emergence of mind. This chapter highlights some current issues and discusses four areas within comparative cognition that are yielding new approaches and hypotheses for studying basic conceptual capacities in nonhuman species. These include studies of imitation, tool use, mirror self-recognition, and the potential for attribution of mental states by nonhuman animals. Though a very old question in psychology, the study of imitation continues to provide new avenues for examining the complex relationships among and between the levels of imitative behaviors exhibited by many species. Similarly, recent work in animal tool use, mirror self- recognition (with all its contentious issues), and recent attempts to empirically study the potential for attributional capacities in nonhumans, all continue to provide fresh insights and novel paradigms for addressing the defining characteristics of these complex phenomena.

Call, J. (2001a). Chimpanzee social cognition. Trends in Cognitive Sciences, 5(9), 388-393.

In the late 1970s, Premack and Woodruff asked whether chimpanzees had a theory of mind. The answer to this question has remained elusive. Whereas some authors argue that chimpanzees are capable of mental state attribution, others maintain that they simply learn certain cues in certain situations. Recent studies challenge both views. On the one hand, chimpanzees know much more about seeing than cue-based explanations suggest; on the other hand, this knowledge does not necessarily entail understanding of the mental states of others. The hypothesis I put forward here is that chimpanzees learn cues in social situations but that they are also capable of knowledge abstraction to solve novel problems.

Epstein, R., Lanza, R. P., & Skinner, B. F. (1981). "Self- awareness" in the pigeon. Science, 212(4495), 695-696.

Three adult White Carneaux pigeons used a mirror to locate a spot on its body that it could not see directly. Although similar behavior in primates has been attributed to a self- concept or other cognitive process, the present example suggests an account in terms of environmental events.

Humle, T., & Matsuzawa, T. (2004). Oil palm use by adjacent communities of chimpanzees at Bossou and Nimba Mountains, West Africa. International Journal of Primatology, 25(3), 551- 581.

We investigated oil palm (Elaeis guineensis) use for feeding in 3 chimpanzee communities: Bossou and Seringbara in Guinea and Yeale in Cote d'Ivoire. Bossou was used as the benchmark for comparison. Bossou chimpanzees ( Pan troglodytes verus) exhibit a wide range of oil palm targeted behaviors. We used direct observations of their two tool use, i.e., nut-cracking and pestle pounding, to establish strict and reliable criteria to ascertain the presence of comparable behaviors at the two adjacent Nimba sites. Based on monthly surveys of oil palms across the three sites, significant differences in patterns of use emerged. Bossou chimpanzees demonstrated the greatest frequency of oil palm use, while Seringbara chimpanzees, 6 km away, failed to exhibit any use and Yeale chimpanzees, 12 km away, showed all uses comparable to Bossou chimpanzees except pestle pounding and mature leaf pith- feeding. We examined the density and distribution of oil palms, tool availability for nut-cracking and pestle pounding, fruit, flower and nut availability, competition with sympatric species for fruit and nuts and the diversity of fruit species in the diet across the 3 sites. We found no clear difference in proximate environmental variables underlying observed variations in oil palm use among the 3 sites, yielding the conclusion that the differences are cultural. Assuming individual interchange between communities and the involvement of social learning in the intracommunity transmission and maintenance of oil palm uses, the result raises interesting questions about diffusion of behavior between neighboring chimpanzee communities.

Jensen, K., Hare, B., Call, J., & Tomasello, M. (2006). What's in it for me? Self-regard precludes altruism and spite in chimpanzees. Proceedings of the Royal Society B-Biological Sciences, 273(1589), 1013-1021.

Sensitivity to fairness may influence whether individuals choose to engage in acts that are mutually beneficial, selfish, altruistic, or spiteful. In a series of three experiments, chimpanzees (Pan troglodytes) could pull a rope to access out-of-reach food while concomitantly pulling another piece of food further away. In the first study, they could make a choice that solely benefited themselves (selfishness), or both themselves and another chimpanzee (mutualism). In the next two experiments, they could choose between providing food solely for another chimpanzee (altruism), or for neither while preventing the other chimpanzee from receiving a benefit (spite). The main result across all studies was that chimpanzees made their choices based solely on personal gain, with no regard for the outcomes of a conspecific. These results raise questions about the origins of human cooperative behaviour.

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Povinelli, DJ, Gallup, GG, Eddy, TJ, Bierschwale, DT, Engstrom, MC, Perilloux, HK, Toxopeus, IB (1997) Chimpanzees recognize themselves in mirrors [full text availability]. Animal Behaviour, Vol.53, No.Pt5, Pp.1083- 1088.

Heyes’ (1994, Anim. Behav., 97, 909-919; 1995, Anim. Behav., 50, 1533-1542) recent account of chimpanzees’, Pan troglodytes, reactions to mirrors challenged the view that they are capable of recognizing the equivalence between their mirror images and their physical appearance. In particular, she argued that observations that chimpanzees touch surreptitiously placed marks on their faces while in front of mirrors can be explained as an interaction between ambient levels of face touching and procedural artefacts of the anaesthetization and markings of the subjects. Using new analytical techniques, data are reported that falsify the central predictions generated by her account and confirm predictions derived from the self- recognition model.

Suda, C., & Call, J. (2006). What does an intermediate success rate mean? An analysis of a Piagetian liquid conservation task in the great apes. Cognition, 99(1), 53-71.

The study investigates what an intermediate success rate means in bonobos, chimpanzees, and orangutans. Apes participated in liquid conservation experiments where they had to track the larger of two different quantities of juice after various kinds of transformations [Suda, C., & Call, J. (2004). Piagetian liquid conservation in the great apes (Pan paniscus, Pan troglodytes, and Pongo pygmaeus). Journal of Comparative Psychology, 118, 265-279). When making a decision, apes sometimes demonstrated hesitant behavior, concurrently pointing to both alternatives or successively changing their choice. Moderately Successful apes showed more hesitation than highly Successful or unsuccessful apes. The results are consistent with the cognitive conflict model: The experiments created a higher decree of cognitive conflict on moderately successful apes than on very Successful or unsuccessful apes. This indicates that an intermediate performance reflects the joint operation and potential conflict between two different cognitive strategies (identity and appearance) inherent to the Piagetian conservation task. (C) 2005 Elsevier B.V. All rights reserved.

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Tomasello, M. (1998). Uniquely primate, uniquely human. Developmental Science, 1(1), 1-16.

Proposes 2 hypotheses about primate cognition. First, it is proposed that primates, but not other mammals, understand categories of relations among external entities. In the physical domain primates have special skills in tasks such as oddity, transitivity, and relation matching that require facility with relational categories; in the social domain primates have special skills in understanding the 3rd-party social relationships that hold among other individuals in their groups. Second, it is proposed that humans, but not other primates, understand the causal and intentional relations that hold among external entities. In the physical domain only humans understand causal forces as mediating the connection between sequentially ordered events; in the social domain only humans understand the behavior of others as intentionally directed and controlled by desired outcomes. Both these uniquely primate and these uniquely human cognitive skills are hypothesized to have their origins in adaptations for negotiating complex social interactions. (PsycINFO Database Record (c) 2000 APA, all rights reserved)

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Tomasello, M., Call, J., & Hare, B. (2003). Chimpanzees understand psychological states – the question is which ones and to what extent. Trends in Cognitive Sciences, 7(4), 153-156.

New data suggest that relatively drastic revisions are needed in our theoretical accounts of what other animal species understand about the psychological states of others. Specifically, chimpanzees seem to understand some things about what others do and do not see, or have and have not seen in the immediate past, as well as some things about others' goal-directed activities. This is especially so in competitive situations. They clearly do not have a human-like theory of mind, however, and so the challenge is to specify precisely how ape and human social cognition are similar and different.

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Tomasello, M., Carpenter, M., Call, J., Behne, T., & Moll, H. (2005). Understanding and sharing intentions: The origins of cultural cognition. Behavioral and Brain Sciences, 28(5), 675-+.

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 (and some children with autism) understand the basics of intentional action, but they still do not participate in activities involving joint intentions and attention (shared intentionality). Human children's skills of shared intentionality develop gradually during the first 14 months of life as two ontogenetic pathways intertwine: (1) the general ape line of understanding others as animate, goal-directed, and intentional agents; and (2) 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.

Tomasello, M., & Rakoczy, H. (2003). What makes human cognition unique? From individual to shared to collective intentionality. Mind & Language, 18(2), 121-147.

It is widely believed that what distinguishes the social cognition of humans from that of other animals is the belief- desire psychology of four-year-old children and adults (so- called theory of mind). We argue here that this is actually the second ontogenetic step in uniquely human social cognition. The first step is one year old children's understanding of persons as intentional agents, which enables skills of cultural learning and shared intentionality. This initial step is 'the real thing' in the sense that it enables young children to participate in cultural activities using shared, perspectival symbols with a conventional/normative/reflective dimension-for example, linguistic communication and pretend play-thus inaugurating children's understanding of things mental. Understanding beliefs and participating in collective intentionality at four years of age-enabling the comprehension of such things as money and marriage-results from several years of engagement with other persons in perspective-shifting and reflective discourse containing propositional attitude constructions.

Whiten, A. (2005). The second inheritance system of chimpanzees and humans. Nature, 437(7055), 52-55.

Half a century of dedicated field research has brought us from ignorance of our closest relatives to the discovery that chimpanzee communities resemble human cultures in possessing suites of local traditions that uniquely identify them. The collaborative effort required to establish this picture parallels the one set up to sequence the chimpanzee genome, and has revealed a complex social inheritance system that complements the genetic picture we are now developing.