Emotional Contagion From the Heart Between Humans and Dogs

Different measures of heart rate variability are indicators of heartfelt emotional contagion between humans and dogs.

A good deal of research has clearly shown that dogs and humans read one another very well, and this ability seems to be related to the long period of association between both social mammals during the domestication process. (See Canine Confidential, Unleashing your Dog.) These shared emotions function as "social glue" and help to develop and to maintain strong and enduring social bonds.

Not much is known about the underlying variables that influence how emotions are shared, often called "emotional contagion," and a new study published in Frontiers in Psychology by Maki Katayama and her colleagues called "Emotional Contagion From Humans to Dogs Is Facilitated by Duration of Ownership" sheds some light on these relationships. This essay is available for free online, so here are a few snippets to whet your appetite for more information about this very interesting study and what the data suggest about the nature of dog-human relationships and physiological—in this case heartfelt—correlates.

To study the factors that influence emotional contagion from humans to dogs, the researchers used heart rate variability (HRV), which changes in seconds, as a measure of autonomic nervous system activity and "positive emotional states" because previous studies have shown that this is a reliable relationship. Thirty-four dogs and their humans were studied, however, data from only 14 pairs were used in the final analyses.

Maki Katayama and her colleagues compared changes of HRV indices in humans and their dog in a stressful situation. After both were fitted with an electrocardiogram device and rested for 40 minutes, the dog and their human went into an experimental room for 30 minutes. Next, humans were exposed to stress using a slightly modified version of the Trier social stress test (TSST) in which humans were criticized for making mistakes when performing verbal mental arithmetic. So that the dogs didn't know their humans were being criticized, the researchers used a board showing the statement “It’s an error. Repeat the calculation again".

Heartfelt empathy

All in all, this study showed that emotional contagion indicated by various measures of HRV "can be transferred from the owner to the dogs, and the efficacy of the emotional contagion was depending (sic) of the duration of the time-sharing with dog and owners."¹ In addition, female dogs were more sensitive than males to the stress displayed by their humans. Another study by different researchers using variations in hair cortisol concentration levels also has shown that dogs mirror our stress levels in different situations. (See "Dumping the Dog Domestication Dump Theory Once and For All" for further discussion of physiological correlates of dog-human relationships.)

Stay tuned for further discussions on the nature of dog-human emotional connections and the various factors that can influence this relationship. When dogs "talk" from their hearts, we must listen carefully to what they want and need. (See "Calling All Dogs to a 'Talkout' Summit to Speak Their Hearts.") The above study is a good beginning toward teasing out the variables that influence heartfelt emotional contagion between humans and their canine companions. These data can be used to develop and maintain mutually beneficial relationships from which both dogs and humans benefit, a win-win for all.