February 23, 2025, 9:43 am | Read time: 5 minutes
Dogs communicate not only by barking but, above all, through body language. This also includes subtle facial movements such as blinking or licking the nose. One study shows that the animals even respond to each other — similar to what has been observed in primates and cats.
Visual signals play a central role in the communication of many social animals. While blinking has been recognized as a form of social interaction in primates and cats, it was not well understood if dogs also use their facial expressions to react to fellow canines. A study by the University of Parma in Italy has now investigated this in more detail. The study looked at how dogs respond when other dogs blink.
In particular, so-called “blink mimicry” — the reflex-like imitation of a blink — could indicate that dogs perceive their social environment more intensively than previously assumed.
“If You Blink, I Blink Too” — Dogs Blink when Others Blink
The Italian researchers published their findings in the journal Royal Society Open Science, revealing intriguing results. Until now, it was thought that dogs mainly used blinking as an appeasement signal for de-escalation. If one dog blinks at the other, it wants to let him know that he is peaceful and poses no danger.
However, blinking also appears to have another social component. The researchers, therefore, wanted to see which physical signs the dogs actively responded to among themselves. To do this, they were shown videos in which other dogs either blinked, licked their noses, or simply looked attentively.
At the same time, their heart rate was measured to check whether emotional arousal played a role. The results provide new insights into how dogs communicate with each other – and could even explain why our best friend is so attuned to humans.
More Than Just Reflexes?
In the study, 54 dogs of different breeds and ages were examined. All dogs were tested in the university laboratory. The experiments were conducted in a darkened room where stimuli were projected onto a screen using a video projector.
Three videos were shown to each dog in turn:
- One dog blinked.
- One dog licked its nose.
- One dog looked calmly into the camera (control video).
During the demonstration, cameras recorded the dogs’ behavior, which was then analyzed using the standardized DogFACS behavior coding system. In addition, the dogs’ heart rate was measured with a heart rate monitor to determine whether blinking triggered an emotional response.
The order of the videos varied randomly for each dog in order to rule out possible habituation effects. There were breaks between the individual test runs to allow the animals to relax.
Dogs Did Not Respond to Nose Licking
The results showed that dogs actually blinked more often when watching a blink video than when watching a nose-licking or control video. This response was statistically significant and suggests that dogs do indeed respond to the blinking of their conspecifics as a social cue.
In contrast, the nose-licking video showed no significant responses in the watching dogs. Instead, they more frequently showed a visible sclera, i.e., the whites of their eyes. This could indicate that they perceived the gesture shown as potentially stress- or conflict-related.
The heart rate measurements, on the other hand, showed no differences between the individual video conditions. This indicates that the observed behavioral reactions were not triggered by increased emotional arousal or a reflex but by social interaction.
Dogs Read Each Other and Respond to Signals
The results show for the first time that dogs actually actively respond to the blinking of a conspecific. This suggests that blinking may serve a social function, signaling relaxation or non-verbal consent.
However, the fact that dogs did not respond to the nose-licking of their conspecifics does not suggest that this behavior has a comparable social synchronization. Rather, it could have different meanings depending on the context — from stress relief to appeasement.
The fact that the dogs were able to classify this was shown by the slightly tense look in which the researchers could see the whites of the animals’ eyes. Both gestures could, therefore, actually represent a conscious social reaction. 1
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Phenomenon Still Needs to Be Investigated More Thoroughly
This study provides new insights into the fact that dogs use their facial expressions specifically to communicate with conspecifics. It would be exciting to examine the communication between humans and dogs for the same dynamics in a further study.
This could make the interaction between owner and animal much easier and provide clarity in uncertain situations. For instance, understanding the difference when a dog does not blink at another dog during a walk but instead uses a steady gaze. Further work on this topic could make it easier for us to better read the subtle cues of our four-legged friends.
However, there are also some limitations, as the dogs reacted to videos rather than to other dogs present. Direct social interaction could be different. In addition, mainly dogs with medium-length snouts were examined. It remains to be seen whether the short muzzle of a Pug or the long muzzle of an Afghan Hound affects communication.
Additionally, dogs learn from experience. Their response to facial movements could depend on their socialization and previous interactions with other dogs or humans. Despite these limitations, the study is an important step towards understanding how dogs communicate non-verbally with each other and the importance of seemingly subtle body language cues.