Interview with Dr Min Hooi Yong
Dr Min Hooi Yong is a lecturer at Sunway University, Malaysia. Her research interests are in the shared and different mechanisms in empathy development between humans and nonhuman species. In this interview she speaks about her research in whether dogs are able to recognise human emotions… “The increase in cortisol levels, coupled with the increased alert and submissive behaviour, suggests that dogs find crying distressing”
1. Min, you have recently completed your PhD, please tell us a little bit about your research
My research investigated whether domestic dogs could differentiate human emotional expressions when expressed by an unfamiliar human. Specifically, I examined 4 emotions (anger, sadness, fear, happiness) and 3 types of expressions (unimodal, bimodal, dynamic) in four studies. The four studies were command task, social referencing, matching-to-sample, and infant crying sounds task. In addition, I compared whether canine responses were similar to those of humans and, therefore, included both young adults and infants in two studies. Results showed that dogs responded similarly to fear and control expressions, but differently to a happy expression in a social referencing task, suggesting that they might not have understood the fearful expression meaningfully (Yong & Ruffman, 2015). However, dogs were able to discriminate happiness and anger in a command task, but in a matching-to-sample task, they looked equally at both expressions and looked much less at sad faces compared to happy and angry faces, similar to human infants. In the crying sounds study, both dogs and humans had increased cortisol levels after listening to a human infant crying but not to babbling or white noise. Dogs also showed a combination of alert and submissive behaviour when listening to crying, but not to the others (Yong & Ruffman, 2014). In conclusion, the results provided some evidence that dogs tended to respond differently to human emotional expressions and, similar to humans, may have an aversion to human expressions of sadness, indicating the presence of emotional contagion, a form of rudimentary empathy.
2. Some of your research has shown that dogs show signs of emotional contagion to human distress. Do you think this could have implications for their welfare?
Definitely. When we observe a dog approaching a crying person (Custance & Mayer, 2012; Yong & Ruffman, 2014), we immediately think that “this dog understands that I am feeling sad”. While this thought gives us comfort and generally induces more loving responses from us, we fail to recognise that our crying is actually distressing to them. My research showed that dogs experienced an increase in cortisol levels, as measured in their saliva, after listening to crying, similar to young adult humans (Yong & Ruffman, 2014). The increase in cortisol levels coupled with the increased alert and submissive behaviour suggests that dogs find the crying sound distressing. Therefore, we as owners, should be aware that exposure to distressing situations e.g. crying, may have a detrimental effect on their health and welfare. In addition, dogs are a popular choice for animal-assisted therapy (AAT) for both children and adults. AAT dogs have a higher frequency of being exposed to crying bouts and this would certainly not be healthy for the dogs.
3. In your opinion do you think knowledge of how dogs respond to human emotion is considered enough? And what research/education is needed?
In short, the answer is no. Dogs are an ideal social cognition animal model. Unlike other animals, dogs have higher exposure to human emotional expressions, because of their involvement in human activities, including distress. The long history of domestication has certainly shown that dogs are superior in some human communicative cues e.g. pointing and gazing, compared to other species (Miklosi & Soproni, 2006), which contributes to their ability in recognising our human emotions. The current research activities in social cognition in dogs, specifically using emotions as stimuli is certainly flourishing and have contributed to the overall body of knowledge. Nonetheless, I strongly encourage more research in other forms and not limited to laboratory ones. We need research that are both ecologically valid, and across types (laboratory-raised, companion, working) and using other forms of stimuli. The recent interest in citizen science research can be applied easily (Dickinson, Zuckerberg, & Bonter, 2010). For example, we do not have qualitative feedback on owner’s perception of their dogs’ responses. Considering that these dogs spend almost all of their time with a familiar human, owners/familiar humans could provide valuable feedback on dogs’ responses.
* Any views or opinions represented in this interview are personal and belong solely to the interviewee, and do not necessarily represent the views or policies of World Animal Protection.