Can domestic dogs (Canis familiaris) use referential emotional expressions to locate hidden food?

Abstract

Although many studies have investigated domestic dogs' (Canis familiaris) use of human communicative cues, little is known about their use of humans' emotional expressions. We conducted a study following the general paradigm of Repacholi in Dev Psychol 34:1017-1025, (1998) and tested four breeds of dogs in the laboratory and another breed in the open air. In our study, a human reacted emotionally (happy, neutral or disgust) to the hidden contents of two boxes, after which the dog was then allowed to choose one of the boxes. Dogs tested in the laboratory distinguished between the most distinct of the expressed emotions (Happy-Disgust condition) by choosing appropriately, but performed at chance level when the two emotions were less distinct (Happy-Neutral condition). The breed tested in the open air passed both conditions, but this breed's differing testing setup might have been responsible for their success. Although without meaningful emotional expressions, when given a choice, these subjects chose randomly, their performance did not differ from that in the experimental conditions. Based on the findings revealed in the laboratory, we suggest that some domestic dogs recognize both the directedness and the valence of some human emotional expressions.

A Shared System of Representation Governing Quantity Discrimination in Canids

“…There were some small but nevertheless important procedural differences between Ward and Smuts (2007) and the results reported here; for example, the dogs used in Ward and Smuts (2007) were tested in a single testing room environment that was devoid of distractions, while the dogs used in the current study were tested at their own homes. Importantly, despite such environmental differences, similar results were obtained; this contrasts with other recent tests of canine choice behavior in lab vs. open-air environments, where differences in dogs’ choice behavior based on referential emotions displayed by the experimenter have specifically been found (Buttelmann and Tomasello, 2012; though breed also was confounded with testing environment in these conditions). Thus, our replication will do well to justify future research endeavors, which intend to test canid quantitative discrimination abilities in a naturalistic environment.…”

“…Similarly, the dogs did not reach 100% accuracy on all visual trials – even though the experimenter always knew which side held the larger food item – suggesting lack of use of any unintentional human cues. Moreover, as reported by Buttelmann and Tomasello (2012), domestic dogs do not modify their choice behavior when humans display non-meaningful emotional expressions in the direction of one of two choices. The experimenter in the current study remained emotionally neutral throughout all trials.…”

Decoding Human Emotional Faces in the Dog’s Brain

“…Although we cannot determine the degree of attention that dogs paid to our stimuli, this interpretation is compatible with the fact that happy faces are salient for dogs. Several behavioral studies in dogs have not found differences between happy and neutral human faces 5,6,28,33 , yet we found differences in brain activity related to these two types of stimuli. Our results suggest that the specific brain activity to happy human faces reflects that these stimuli are important for dogs.…”

Humans Process Dog and Human Facial Affect in Similar Ways

“…Among others, the evidence includes the dog’s capacity to learn spoken words and symbols [2], to know when a human communication is intended for it [3], and to understand human gestures like pointing [4]. Importantly for the present study, there is also evidence that dogs are sensitive to human emotional expressions and use these expressions to guide their actions [5], [6]. For example, when faced with a novel object, dogs will look at their owner and more readily approach the object if their owner talks in an encouraging as compared to a discouraging manner [6].…”