Abstract: The present study investigated the influence of temperament on long-term recall and extinction of 2 instrumental tasks in 26 horses. In the first task (backward task), horses learned to walk backward, using commands given by an experimenter, in order to obtain a food reward. In the second task (active avoidance task), horses had to cross an obstacle after a bell rang in order to avoid emission of an air puff. Twenty-two months after acquisition, horses exhibited perfect recall performance in both tasks. Accordingly, no influence of temperament on recall performance could be observed for either task. In contrast, in the absence of positive or negative outcomes, the horses’ ability to extinguish their response to either task was highly variable. Resistance to extinction was related to some indicators of temperament: The most fearful horses tended to be the most resistant to extinction in the backward task, while the least sensitive horses tended to be the most resistant to extinction in the active avoidance task. These findings reveal extensive long-term memory abilities in horses and suggest an influence of temperament on learning processes other than acquisition.

Abstract: The study examines whether untrained dogs and infants take their caregiver’s visual experience into account when communicating with them. Fifteen adult dogs and 15 one-year-old infants were brought into play with their caregivers with one of their own toys. The caregiver gave the toy to the experimenter, who, in different conditions, placed it either above or under one of two containers, with both the infant or dog and the caregiver witnessing the positioning; in a third condition, the caregiver left the room before the toy was placed under one of the two containers and later returned. Afterwards, for each condition, the caregiver asked the participant to indicate the location of the toy. Neither dogs nor infants—untrained to the use of the partner’s knowledge state—showed much difference of behaviour between the three conditions. However, dogs showed more persistence for most behaviours (gaze at the owner, gaze at the toy and gaze alternation) and conditions, suggesting that the situation made more demands on dogs’ communicative behaviours than on those of infants. When all deictic behaviours of infants (arm points towards the toy and gaze at the toy) were taken into account, dogs and infants did not differ. Phylogeny, early experience and ontogeny may all play a role in the ways that both species communicate with adult humans.

Abstract: ven young humans show sensitivity to the accuracy and reliability of informants’ reports. Children are selective in soliciting information and in accepting claims. Recent research has also investigated domestic dogs’ (Canis familiaris) sensitivity to agreement among human informants. Such research utilizing a common human pointing gesture to which dogs are sensitive in a food retrieval paradigm suggests that dogs might choose among informants according to the number of points exhibited, rather than the number of individuals indicating a particular location. Here, we further investigated dogs’ use of information from human informants using a stationary pointing gesture, as well as the conditions under which dogs would utilize a stationary point. First, we explored whether the number of points or the number of individuals more strongly influenced dogs’ choices. To this end, dogs encountered a choice situation in which the number of points exhibited toward a particular location and the number of individuals exhibiting those points conflicted. Results indicated that dogs chose in accordance with the number of points exhibited toward a particular location. In a second experiment, we explored the possibility that previously learned associations drove dogs’ responses to the stationary pointing gesture. In this experiment, dogs encountered a choice situation in which artificial hands exhibited a stationary pointing gesture toward or away from choice locations in the absence of humans. Dogs chose the location to which the artificial hand pointed. These results are consistent with the notion that dogs may respond to a human pointing gesture due to their past-learning history.

Abstract: Animal communication has become a widely studied field of research, especially because of the associated debates on the origin of human language. Due to their phylogenetic proximity with humans, non-human primates represent a suitable model to investigate the precursors of language. This study focuses on the perception of the attentional states of others, an important prerequisite to intentional communication. We investigated whether capuchins (Cebus apella) produce a learnt pointing gesture towards a hidden and unreachable food reward as a function of the attentional status of the human experimenter. For that purpose, we tested five subjects that we first trained to indicate by a pointing gesture towards the human partner the position of a reward hidden by an assistant. Then, capuchins were tested in two experimental conditions randomly ordered. In the first condition—motivation trial—the experimenter was attentive to the subject gestures and rewarded him immediately when it pointed towards the baited cylinder. During the second condition—test trial—the experimenter adopted one of the following attention states and the subject was rewarded after 10 s has elapsed, regardless of the subject’s behaviour. Five attentional states were tested: (1) experimenter absent, (2) experimenter back to the monkey, (3) experimenter’s head away, (4) experimenter watching above the monkey, and (5) experimenter watching the monkey face. Our results reveal a variation in our subjects’ communicative behaviours with a discrimination of the different postural clues (body and head orientation) available in our experimental conditions. This study suggests that capuchins can flexibly use a communicative gesture to adapt to the attentional state of their partner and provides evidence that acquired communicative gestures of monkeys might be used intentionally.

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.