Do dogs have an aversion to sadness?
This is Min's second blog for the Gloabl Animal Network and here she talks about her fascinating research exploring how dogs process human emotions.
In my previous post, I mentioned about how we treat our dogs as a family member, expecting them to recognise our human emotions. Maybe the expectation is a wee bit high, but we certainly hope that they do. Doesn’t it feel wonderful if Fido recognises that we are happy from our smiling faces, or from the high-pitched squeal when we receive a much-wanted birthday gift?
We wanted to know whether dogs could match emotional faces to voices in an intermodal matching task, or whether they show preferences for looking at specific emotions over others, similar to human infants (Yong & Ruffman, 2016). An intermodal matching task or also known as Matching-to-Sample (MTS) is when two facial expressions are presented together with an auditory expression, with the interest in whether the observer looks more at the facial expression that matches the auditory expression.
Past research in human infant studies shows that 7-month-olds sometimes can match faces to a corresponding voice (Montague & Walker–Andrews, 2002; Soken & Pick, 1992, 1999). But results also showed that matching occurred in less than half (41%) of published studies. Instead, infants sometimes display preferences for certain facial emotions over others e.g. look more at happy faces when paired with either sad or angry faces, and no preference when sad and angry faces are paired.
What about dogs’ performance in human emotions? Muller et al. (2015) found that dogs approached happy faces faster compared to angry faces, and learned more quickly when rewarded with happy versus angry faces. Albuquerque et al. (2016) found that dogs could match visual and auditory expressions of anger and happiness in both dogs’ and human stimuli.
In our study, we presented 52 dogs and 24 7-month-old human infants with two different human emotional facial expressions of the same gender simultaneously, while listening to a human voice expressing an emotion that matched one of them. We included three different emotions; happy, anger and sad for every participant. The two negative emotions — anger and sadness — are to test dogs’ matching ability more comprehensively compared to previous studies. Our results were consistent with most matching studies, in that neither dogs nor infants looked longer at the matching emotional stimuli. Instead, both dogs and humans demonstrated an identical pattern of looking less at sad faces when paired with happy or angry faces (irrespective of the voice), with no preference for happy versus angry faces.
The similarity between dogs’ and infant looking preferences can be viewed either as a preference to look at happy and angry faces or as an aversion to sad faces. The aversion to sad faces could be that both dogs and infants try to reduce stressful visual information from sad faces. When infants view a crying person, they become more agitated, grimaced more, and play less.
Our findings demonstrate that dogs process emotional faces similarly to human infants, detecting differences in facial emotions and showing viewing preferences just like human infants. Taken together with dogs’ response when listening to infant crying (Yong & Ruffman, 2014), sadness is likely aversive to dogs, thus pointing to another indicator of emotional contagion.
Albuquerque, N., Guo, K., Wilkinson, A., Savalli, C., Otta, E., & Mills, D. (2016). Dogs recognize dog and human emotions. Biology Letters, 12(1), 20150883.
Montague, D. P. F., & Walker–Andrews, A. S. (2002). Mothers, fathers, and infants: The role of person familiarity and parental involvement in infants’ perception of emotion expressions. Child Development, 73(5), 1339–1352.
Müller, C. A., Schmitt, K., Barber, A. L. A., & Huber, L. (2015). Dogs can discriminate emotional expressions of human faces. Current Biology, 25(5), 601–605.
Soken, N. H., & Pick, A. D. (1992). Intermodal perception of happy and angry expressive behaviors by seven-month-old infants. Child Development, 63(4), 787–795.
Soken, N. H., & Pick, A. D. (1999). Infants’ perception of dynamic affective expressions: Do infants distinguish specific expressions? Child Development, 70(6), 1275–1282.
Yong, M. H., & Ruffman, T. (2014). Emotional contagion: Dogs and humans show a similar physiological response to human infant crying. Behavioural Processes, 108, 155–165.
Yong, M. H., & Ruffman, T. (2016). Domestic dogs and human infants look more at happy and angry faces than sad faces. Multisensory Research.
* This is a personal blog. Any views or opinions represented in this blog belong solely to the blog owner and do not necessarily represent the views or policies of World Animal Protection.