Fellow humans may look alarmed or move away when you show anger, but your dog will likely lick his mouth. Researchers trying to determine whether dogs truly had an understanding of human emotion discovered that yes, indeed they do–and they consistently demonstrate that understanding by licking their mouths when humans express anger.
Animal behavior researchers in the UK and Brazil have found that dogs lick their mouths as a response to angry human faces, according to new study.
Scientists examined the behavior of dogs in response to emotionally significant images and sounds, and found that mouth licking in domestic dogs is not simply a response to food or uncertainty, but appears to be used as a signal to try to communicate with humans in response to visual cues of anger.
Significantly, audio cues of angry human voices did not elicit the same response.
Dogs were exposed simultaneously to two facial expressions (one positive and one negative from the same individual), which could be either human or canine of either sex, along with a sound, which could be positive or negative from the same species and gender.
The findings indicate that this mouth licking behavior is linked to the animals’ perception of negative emotions and shine new light on our understanding of the emotional world of dogs.
Journal Reference: Natalia Albuquerque, Kun Guo, Anna Wilkinson, Briseida Resende, Daniel S. Mills. Mouth-licking by dogs as a response to emotional stimuli. Behavioural Processes, 2018; 146: 42 DOI: 10.1016/j.beproc.2017.11.006