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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2009.03.008 Byline: Claudio Tennie (a), Eileen Glabsch (a), Sebastian Tempelmann (a)(b), Juliane Brauer (a), Juliane Kaminski (a)(c), Josep Call (a) Abstract: Contextual imitation of intransitive actions within a third-party copying setting was tested in 180 household dogs. A demonstrator dog, in sight of observer dogs, performed one of two trained actions upon hearing verbal commands given by an experimenter. Observer dogs were later tested to see whether they produced more target actions than control groups who had not seen demonstrations of those actions. In all conditions, except one, the demonstrated actions had been previously trained in the observer dogs by their owners, but had been attached to a different verbal command to that used in our study. For these 'pretrained' actions we further investigated whether reward contingency, the relationship of the dog to the human experimenter and ostensive cues had an effect. In no condition did we find any contextual imitation. A subsample of all tested dogs had, during their lifetimes, received extensive training in a diverse range of tasks outside of social learning, but this background similarly did not lead to contextual imitation. We conclude that dogs, even when highly trained, fail to show evidence of contextual imitation for intransitive actions within a third-party copying paradigm. Author Affiliation: (a) Department of Comparitive Psychology, Max Planck Institute for Evolutionary Anthropology, Germany (b) Department of Psychology, University of Portsmouth, U.K. (c) Sub-Department of Animal Behaviour, University of Cambridge, U.K. Article History: Received 19 August 2008; Revised 15 October 2008; Accepted 9 March 2009 Article Note: (miscellaneous) MS. number: 08-00548R

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2007.08.010 Byline: Julia Riedel, Katrin Schumann, Juliane Kaminski, Josep Call, Michael Tomasello Abstract: Although dogs, Canis familiaris, are skilful at responding to human social cues, the role of ontogeny in the development of these abilities has not been systematically examined. We studied the ability of very young dog puppies to follow human communicative cues and successfully find hidden food. In the first experiment we compared 6-, 8-, 16- and 24-week-old puppies in their ability to use pointing gestures or a marker as a cue. The results showed that puppies, independent of age, could use all human communicative cues provided; only their success at using the marker cue increased with age. In the second and third experiments we investigated the flexibility of the puppies' understanding by reducing the degree to which they could use local enhancement to solve these problems. Here, subjects could not simply approach the hand of the experimenter and follow its direction to the correct location because cups were placed next to the dog instead of next to the experimenter. Six-week-old puppies readily used all of the human communicative cues provided. These findings support the hypothesis that domestication played a critical role in shaping the ability of dogs to follow human-given cues. Author Affiliation: Department of Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, Germany Article History: Received 12 January 2007; Revised 2 March 2007; Accepted 28 August 2007 Article Note: (miscellaneous) MS. number: 9231R

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2007.04.018 Byline: Jana Uher, Jens B. Asendorpf, Josep Call Abstract: Using a multidisciplinary approach, the present study complements ethological behaviour measurements with basic theoretical concepts, methods and approaches of the personality psychological trait paradigm. Its adoptability and usefulness for animal studies are tested exemplarily on a sample of 20 zoo-housed great apes (five of each of the following species): bonobos, Pan paniscus; chimpanzees, Pan troglodytes verus; gorillas, Gorilla gorilla gorilla; and orang-utans, Pongo pygmaeus abelii. Data on 76 single trait-relevant behaviours were recorded in a series of 14 laboratory-based situations and in two different group situations. Data collection was repeated completely after a break of 2 weeks within a 50-day period. All behaviour records were sufficiently reliable. Individual- and variable-oriented analyses showed high/substantial temporal stability on different levels of aggregation. Distinctive and stable individual situational and response profiles clarified the importance of situations and of multiple trait-relevant behaviours. The present study calls for a closer collaboration between behavioural biologists and personality psychologists to tap the full potential of animal personality research. Author Affiliation: (a) Humboldt-University Berlin, Institute for Psychology, Germany (a ) Max Planck Institute for Evolutionary Anthropology, Germany Article History: Received 22 June 2006; Revised 5 March 2007; Accepted 17 April 2007 Article Note: (miscellaneous) MS. number: 9010R2

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2004.05.008 Byline: Juliane Kaminski, Julia Riedel, Josep Call, Michael Tomasello Abstract: Gaze following is a basic social cognitive skill with many potential benefits for animals that live in social groups. At least five primate species are known to follow the gaze of conspecifics, but there have been no studies on gaze following in other mammals. We investigated whether domestic goats can use the gaze direction of a conspecific as a cue to find food. They were able to do this, at a level comparable to that of primates. In a second experiment, we tested goats' ability to use gaze and other communicative cues given by a human in a so-called object choice situation. An experimenter hid food out of sight of the subject under one of two cups. After baiting the cup the experimenter indicated the location of the food to the subject by using different cues. The goats used communicative cues (touching and pointing) but not gaze by itself. Since domestic dogs are very skilled in this task, whereas wolves are not, one hypothesis is that the use of communicative cues in the object choice task is a side-effect of domestication. Author Affiliation: Max Planck Institute for Evolutionary Anthropology, Germany Article History: Received 18 November 2003; Revised 21 January 2004; Accepted 20 May 2004 Article Note: (miscellaneous) MS. number: 7910R

Stumptailed macaques, Macaca arctoides, have a high conciliatory tendency, according to research using multivariate analysis to investigate the relative significance of factors that may have an impact on the occurrence of reconciliation or specific postconflict behaviour patterns. The multivariate approach made it possible to determine the factors affecting the occurrence of reconciliation. These were found to be initial interopponent distance in postconflict, friendship and kinship.

Individuals belonging to five primates species were investigated experimentally for their capacity to follow the gaze of conspecifics to an outside object. The species were chimpanzees, sooty mangabeys, rhesus macaques, stumptail macaques and pigtail macaques. Results showed that subjects from all species were able to follow the gaze of conspecifics, looking to the food about 80% of the time in experimental trials, in contrast to 20% of the time in control trials.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2009.06.031 Byline: Brian Hare (a), Alexandra Rosati (a), Juliane Kaminski (b), Juliane Brauer (b), Josep Call (b), Michael Tomasello (b) Author Affiliation: (a) Department of Evolutionary Anthropology & Center for Cognitive Neuroscience, Duke University, Durham, NC, U.S.A. (b) Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany Article History: Received 7 February 2009; Revised 15 June 2009; Accepted 25 June 2009 Article Note: (miscellaneous) MS. number: AF-09-00115R

• Non-human primates show reciprocity as observation and experimental studies reveal. • Negative findings can be used to develop a more comprehensive theory of reciprocity. • Reciprocity has been underestimated in non-human primates. Reciprocity is a ubiquitous and important human trait. Still, the evolutionary origin is largely unclear, partly because it is believed that our closest living relatives, other primates, do not reciprocate help. Consequently, reciprocity is suggested to have evolved in the human linage only. However, our systematic review of studies investigating reciprocity in non-human primates revealed that, contrary to common perception, there are more positive than negative findings in both experimental and observational studies. Furthermore, we argue that negative findings can provide important insights. We found that reciprocity is not confined to unrelated individuals. In addition, reciprocity can be influenced by the choice of experimental design, relationship quality, social services and temporal scales. Thus, negative findings should not be used as evidence of no reciprocity but as the building blocks for a more comprehensive theory. Based on our review, we conclude that reciprocity in primates is present but underestimated. We close by suggesting further steps that could pave the way for future research aimed at understanding the evolutionary origins of reciprocity. [ABSTRACT FROM AUTHOR]

Abstract Cooperation often comes with the temptation to defect and benefit at the cost of others. This tension between cooperation and defection is best captured in social dilemmas like the Prisoner's Dilemma. Adult humans have specific strategies to maintain cooperation during Prisoner's Dilemma interactions. Yet, little is known about the ontogenetic and phylogenetic origins of human decision-making strategies in conflict scenarios. To shed light on this question, we compared the strategies used by chimpanzees and 5-year old children to overcome a social dilemma. In our task, waiting for the partner to act first produced the best results for the subject. Alternatively, they could mutually cooperate and divide the rewards. Our findings indicate that the two species differed substantially in their strategies to solve the task. Chimpanzees became more strategic across the study period by waiting longer to act in the social dilemma. Children developed a more efficient strategy of taking turns to reciprocate their rewards. Moreover, children used specific types of communication to coordinate with their partners. These results suggest that while both species behaved strategically to overcome a conflict situation, only children engaged in active cooperation to solve a social dilemma. [ABSTRACT FROM AUTHOR]

Research into social problem solving in chimpanzees seeks to determine their skills in understanding what conspecifics see and do not see.

Research is presented describing the social problem-solving behavior of chimpanzees, Pan troglodytes. A dominant and subordinate individual are put into competition over food and are found to monitor each others' behavior.

On the 30th anniversary of Premack and Woodruff''s seminal paper asking whether chimpanzees have a theory of mind, we review recent evidence that suggests in many respects they do, whereas in other respects they might not. Specifically, there is solid evidence from several different experimental paradigms that chimpanzees understand the goals and intentions of others, as well as the perception and knowledge of others. Nevertheless, despite several seemingly valid attempts, there is currently no evidence that chimpanzees understand false beliefs. Our conclusion for the moment is, thus, that chimpanzees understand others in terms of a perception–goal psychology, as opposed to a full-fledged, human-like belief–desire psychology. [Copyright &y& Elsevier]

Previous studies have shown that dogs have developed a special sensitivity to the communicative signals and attentional states of humans. The aim of the current study was to further investigate what dogs know about the visual perception of humans and themselves. In the first two experiments we investigated whether dogs were sensitive to the properties of barriers as blocking the visual access of humans. We presented dogs with a situation in which a human forbade them to take a piece of food, but the type and orientation of the barrier allowed the dog to take the food undetected in some conditions. Dogs differentiated between effective and ineffective barriers, based on their orientation or the particular features of the barriers such as size or the presence of window. In the third study we investigated whether dogs know about what they themselves have seen. We presented subjects with two boxes and placed food in one of them. In the Seen condition the location of the food was shown to the dogs while in the Unseen condition dogs were prevented from seeing the destination of the food. Before selecting one of the boxes by pressing a lever, dogs had the opportunity to seek extra information regarding the contents of the boxes, which would be particularly useful in the condition in which they had not seen where the food was hidden. Dogs rarely used the opportunity to seek information about the contents of the box before making their choice in any condition. Therefore, we found no evidence suggesting that dogs have access to what they themselves have seen, which contrasts with the positive evidence about visual perspective taking in others from the first two experiments and previous studies. [Copyright &y& Elsevier]

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. [Copyright &y& Elsevier]

An abstract of the article "Past and Present Challenges in Theory of Mind Research in Nonhuman Primates," by Josep Call is presented.

There is substantial evidence for human infants' use of 2 different number processing systems, Object-File System and Approximate Number System; however, the majority of studies of non-human primates reveal processing via Approximate Number System only. The present study investigated whether apes use the Object-File System when tested with an entity-first design, often used in infant studies. Apes' performance was consistently ratio-dependent and showed no sign of an Object-File System, regardless of entity type (rigid and flexible cohesive objects vs. non-cohesive powder and liquid). After ruling out other low-level explanations, our results suggest that great apes relied solely on an Approximate Number System. These results are discussed in light of a possible developmental difference between human infants and adult great apes. [ABSTRACT FROM AUTHOR]

Abstract: Numerous studies have documented the ability of many species to make relative quantity judgments using an analogue magnitude system. We investigated whether one beluga whale, Delphinapterus leucas, and three bottlenose dolphins, Tursiops truncatus, were capable of selecting the larger of two sets of quantities, and analyzed if their performance matched predictions from the object file model versus the analog accumulator model. In Experiment 1, the two sets were presented simultaneously, under water, and they were visually (condition 1) or echoically (condition 2) available at the time of choice. In experiment 2, the two sets were presented above the water, successively (condition 1) or sequentially, item-by-item (condition 2), so that they were not visually available at the time of choice (condition 1) or at any time throughout the experiment (condition 2). We analyzed the effect of the ratio between quantities, the difference between quantities, and the total number of items presented on the subjects’ choices. All subjects selected the larger of the two sets of quantities above chance levels in all conditions. However, unlike most previous studies, the subjects’ choices did not match the predictions from the accumulator model. Whether these findings reflect interspecies differences in the mechanisms which underpin relative quantity judgments remains to be determined. [Copyright &y& Elsevier]

Abstract: Although an extensive body of literature exists on the cognitive underpinnings of gaze movements in macaques and humans, few studies have investigated this topic from a broader evolutionary perspective. This study used the gap–overlap paradigm to examine the timing of the gaze movements by four hominid species: humans, chimpanzees, gorillas, and orangutans. The saccade latency involved in shifting the gaze from central to peripheral stimuli was measured and compared under two conditions, gap and overlap. The central stimulus disappeared shortly before the onset of the peripheral stimulus under the gap condition, but it remained under the overlap condition. Although all species demonstrated similar saccade latencies under the gap condition, the species clearly differed from one another under the overlap condition, which may suggest their similar perceptual and motor mechanism of making a saccade on the one hand and their differential strategies for coping with the competition between two activities involving fixation and initiation of a saccade (i.e. central vs. peripheral visual stimuli) on the other hand. In particular, humans showed longer saccade latency under the overlap condition compared to the other great apes, which may reflect this species’ unique means of visual processing. [Copyright &y& Elsevier]

Emotion is one of the central topics in animal studies and is likely to attract attention substantially in the coming years. Recent studies have developed a thermo-imaging technique to measure the facial skin temperature in the studies of emotion in humans and macaques. Here we established the procedures and techniques needed to apply the same technique to great apes. We conducted two experiments respectively in the two established research facilities in Germany and Japan. Total twelve chimpanzees were tested in three conditions in which they were presented respectively with the playback sounds (Exp. 1) or the videos (Exp. 2) of fighting conspecifics, control sounds/videos (allospecific display call: Exp. 1; resting conspecifics: Exp. 2), and no sound/image. Behavioral, hormonal (salivary cortisol) and heart-rate responses were simultaneously recorded. The nasal temperature of chimpanzees linearly dropped up to 1.5 °C in 2 min, and recovered to the baseline in 2 min, in the experimental but not control conditions. We found the related changes in excitement behavior and heart-rate variability, but not in salivary cortisol, indicating that overall responses were involved with the activities of sympathetic nervous system but not with the measureable activities of the hypothalamus–pituitary–adrenal (HPA) axis. The influence of general activity (walking, eating) was not negligible but controllable in experiments. We propose several techniques to control those confounding factors. Overall, thermo-imaging is a promising technique that should be added to the traditional physiological and behavioral measures in primatology and comparative psychology. [ABSTRACT FROM AUTHOR]