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Takaoka, A., Maeda, T., Hori, Y., & Fujita, K. (2015). Do dogs follow behavioral cues from an unreliable human? Anim.Cogn., 18(2), 475–483.
Abstract: Dogs are known to consistently follow human pointing gestures. In this study, we asked whether dogs “automatically” do this or whether they flexibly adjust their behavior depending upon the reliability of the pointer, demonstrated in an immediately preceding event. We tested pet dogs in a version of the object choice task in which a piece of food was hidden in one of the two containers. In Experiment 1, Phase 1, an experimenter pointed at the baited container; the second container was empty. In Phase 2, after showing the contents of both containers to the dogs, the experimenter pointed at the empty container. In Phase 3, the procedure was exactly as in Phase 1. We compared the dogs’ responses to the experimenter’s pointing gestures in Phases 1 and 3. Most dogs followed pointing in Phase 1, but many fewer did so in Phase 3. In Experiment 2, dogs followed a new experimenter’s pointing in Phase 3 following replication of procedures of Phases 1 and 2 in Experiment 1. This ruled out the possibility that dogs simply lost motivation to participate in the task in later phases. These results suggest that not only dogs are highly skilled at understanding human pointing gestures, but also they make inferences about the reliability of a human who presents cues and consequently modify their behavior flexibly depending on the inference.
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Takimoto, A., Kuroshima, H., & Fujita, K. (2010). Capuchin monkeys (Cebus apella) are sensitive to others’ reward: an experimental analysis of food-choice for conspecifics. Anim. Cogn., 13(2), 249–261.
Abstract: Abstract The issue whether non-human primates have other-regarding preference and/or inequity aversion has been under debate. We investigated whether tufted capuchin monkeys are sensitive to others’ reward in various experimental food sharing settings. Two monkeys faced each other. The operator monkey chose one of two food containers placed between the participants, each containing a food item for him/herself and another for the recipient. The recipient passively received either high- or low-value food depending on the operator’s choice, whereas the operator obtained the same food regardless of his/her choice. The recipients were either the highest- or lowest-ranking member of the group, and the operators were middle-ranking. In Experiment 1, the operators chose the high-value food for the subordinate recipient more frequently than when there was no recipient, whereas they were indifferent in their choice for the dominant. This differentiated behavior could have been because the dominant recipient frequently ate the low-value food. In Experiment 2, we increased the difference in the value of the two food items so that both recipients would reject the low-value food. The results were the same as in Experiment 1. In Experiment 3, we placed an opaque screen in front of the recipient to examine effects of visual contact between the participants. The operators’ food choice generally shifted toward providing the low-value food for the recipient. These results suggest that capuchins are clearly sensitive to others’ reward and that they show other-regarding preference or a form of inequity aversion depending upon the recipients and the presence of visual contact.
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Hori, Y., Takimoto, A., & Fujita, K. (2012). Are there breed difference in referential behavior in horses (Equus caballus)? In K. Krueger (Ed.), Proceedings of the 2. International Equine Science Meeting (Vol. in press). Wald: Xenophon Publishing.
Abstract: Domesticated animals are characterized by variability of breeds. There is a great diversity in body size and/or coat color between different breeds. However, there are few scientific researches about difference in cognition and behavior between breeds. Comparison of behavior between breeds may be useful for the study of genetics behind the diversity of cognition and behavior. In the present study, we investigated behavioral differences between horse breeds. We tested two different breeds which have different histories, thoroughbreds and creoles. Thoroughbreds are racing horses which have been exposed to strict selection toward racing performance for about 300 years. Creoles are descendents of horses which were brought to South America by Spanish people in 15th century and used by native cowboys for riding. We compared the behavior in a difficult situation by using an “unsolvable task”. The experimenter put a food reward into a transparent box and closed it firmly so that horses could not take the reward. We compared the referential behavior (gazing behavior toward the experimenter) between thoroughbreds and creoles. We analyzed referential behavior by using generalized linear models (GLM) and model selection by Akaike’s information criterion (AIC). There were no effect of breed in the frequency and the duration of the referential behavior. But the latency before looking at the experimenter tended to be shorter in thoroughbreds than in creoles. This result suggests that there may be breed differences in horses’ social cognition and behavior. However, the effect of sex was also seen. Furthermore, we could not exclude the environmental effect (e. g. feeding environments, trainings) in this study. So we cannot explain the variation in referential behavior by breed effect only. We need to replicate the result by controlling environmental effects.
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Takimoto, A., & Fujita, K. (2008). Are horses (Equus caballus) sensitive to human attentional states? In IESM 2008.
Abstract: The ability to reliably detect what others are attending to seems important for social species to interact with their partners. Domestic horses (Equus caballus) have lived with humans for over five thousand years, hence they might have developed sensitivity to human attention. In the present study, we investigated whether horses would discriminate the situation in which a human experimenter could see them from the situation in which she could not. Specifically, we tested whether horses understand the role of eyes in human attentional states, produce more visual gestures when the experimenter can see their begging behaviors and produce more auditory or tactile gestures when she can not. We used with a slight modification the paradigm that previously yielded support for chimpanzee understanding of human attention (Hostetter et al. 2007). Twelve horses were offered food by the experimenter who showed various attentional states in front of them. We scored frequency of begging behaviors by the horses. In experiment 1, we set three kinds of condition: hand over the eyes, hand over the mouth and away. In the last condition there was only a food in front of horses, which was a control condition. The results showed that horses produced more auditory or tactile begging behaviors when the experimenter“s eyes were not visible than when her eyes were visible, but there was no difference in visual begging behaviors. In experiment 2, we set two kinds of condition: eyes closed and eyes open. The horses also produced more auditory or tactile begging behaviors when the experimenter”s eyes were closed than when they were open. However, there was no difference in visual begging behaviors. These results show that horses discriminate the situation in which humans can see from that in which humans can not. Of special interest, horses increased only auditory or tactile behaviors, not all types of communicative behaviors, when the experimenter could not see their begging behaviors. This result suggests that horses are sensitive to human attentional states. Moreover, horses may do recognize the eyes as an important indicator of whether or not humans will respond to their behavior and they may be able to behave flexibly depending upon human attentional states
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Kuroshima, H., Fujita, K., Adachi, I., Iwata, K., & Fuyuki, A. (2003). A Capuchin monkey (Cebus apella) recognizes when people do and do not know the location of food. Anim. Cogn., 6(4), 283–291.
Abstract: In a previous study, Kuroshima and colleagues demonstrated that capuchin monkeys (Cebus apella) learned to discriminate between a “knower” who inspected a box for food, and a “guesser” who did not. The aim of the present study was to specify whether the subjects learned a simple conditional discrimination or a causal relationship that seeing leads to knowing. In experiment 1, we introduced five types of novel containers to two subjects. Each container was of different shape and color. The subjects gradually learned to reach toward the container the knower suggested. In experiment 2, we diversified the behavior of the knower and the guesser. In experiment 3, in order to eliminate the possibility of discrimination based on differences in the magnitude and the complexity of two trainers, we equated their behaviors. One subject adapted to the novel behaviors of the knower and the guesser, successfully discriminating the two trainers. Thus this monkey clearly learned to use the inspecting action of the knower and the non-inspecting action of the guesser as a discriminative cue to recognize the baited container. This result suggests that one capuchin monkey learned to recognize the relationship between seeing and knowing.
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